@article{2-s2.0-85183051201,

title = {Linking drought indices to atmospheric circulation in Svalbard, in the Atlantic sector of the High Arctic},

author = { K. Migała and E.B. Łupikasza and M. Osuch and M. Opała-Owczarek and P. Owczarek},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85183051201&doi=10.1038%2fs41598-024-51869-z&partnerID=40&md5=d25e4190270ea85c6818d1d7fe511f48},

doi = {10.1038/s41598-024-51869-z},

issn = {20452322},

year  = {2024},

date = {2024-01-01},

journal = {Scientific Reports},

volume = {14},

number = {1},

publisher = {Nature Research},

abstract = {Based on long-term climatological data from Ny-Ålesund, Svalbard Airport—Longyearbyen and the Polish Polar Station at Hornsund, we undertook an analysis of drought indices on Spitsbergen Island, Svalbard, for the period 1979–2019. The features and causes of spatiotemporal variability of atmospheric drought in Svalbard were identified, as expressed by the standardized precipitation evapotranspiration index (SPEI). There were several-year periods with SPEI indicating the dominance of drought or wet conditions. The long-term variability in the annual and half-year (May–October) SPEI values showed a prevalence of droughts in the 1980s and the first decade of the twenty-first century, while wet seasons were frequent in the 1990s and in the second decade of the twenty-first century. The seasonal SPEIs were characteristic of interannual variability. In MAM and JJA, droughts were more frequent after 2000; during SON and DJF of the same period, the frequency of wet seasons increased. The most remarkable changes in the scale of the entire research period occurred in autumn when negative values of SPEI occurred more often in the first part of the period, and positive values dominated in the last 20 years. The long-term pattern of the variables in consecutive seasons between 1979 and 2019 indicates relationships between the SPEI and anomalies of precipitable water and somewhat weaker relationships with anomalies of sea level pressure. The three stations are located at distances of more than 200 km from each other in the northern (Ny-Ålesund), central (Longyearbyen) and southern parts of Svalbard (Hornsund), and the most extreme values of drought conditions depended on the atmospheric circulation which could have been modified by local conditions thus droughts developed under various circulation types depending on the station. However, some similarities were identified in the atmospheric circulation patterns favouring drought conditions at Ny-Ålesund and Hornsund, both having more maritime climates than Longyearbyen. Extremely dry seasons were favoured by anticyclonic conditions, particularly a high-pressure ridge (type Ka) centred over Svalbard, air advection from the eastern sector under an influence of cyclone and negative precipitable water anomalies. During wet seasons anomalies of precipitable water were positive and cyclonic conditions dominated. These results were corroborated by the frequency of regional circulation types during JJA and DJF with the lowest and highest values of SPEI. © 2024, The Author(s).},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-85184839017,

title = {Comparing ERA5 convective environments associated with hailstorms in Poland between 1948–1955 and 2015–2022},

author = { W. Pilorz and I. Laskowski and A. Surowiecki and M. Taszarek and E.B. Łupikasza},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85184839017&doi=10.1016%2fj.atmosres.2024.107286&partnerID=40&md5=003042ae76748ade6c0b67033376c72d},

doi = {10.1016/j.atmosres.2024.107286},

issn = {01698095},

year  = {2024},

date = {2024-01-01},

journal = {Atmospheric Research},

volume = {301},

publisher = {Elsevier Ltd},

abstract = {This study compares the convective parameters between two 8-year periods of hail reporting in Poland: 1948–1955 (period A) and 2015–2022 (period B). The data on hail incidents for period A was derived from hail annuals of the Institute of Meteorology and Water Management, while for period B from the European Severe Weather Database. Period A contains more hail reports (18375) compared to the recent period B (3677). ERA5 reanalysis and thundeR package were used to calculate convective parameters for both periods. Convective environments indicated a more favourable environment for the hail occurrence in period B with larger instability, vertical wind shear and storm-relative helicity. The most widespread event with the largest hailstone ever documented in Poland (14 cm) also occurred in period B, on 24 June 2021. However, the mean number of hail reports per day was higher in period A due to a more effective method of hail reporting. In both periods convective environments were also clearly more favourable for hail in the days with hail exceeding 5 cm in diameter compared to the days with smaller hail and in days with the large quantities of hail reports. This study showed that ERA5 was able to capture convective environments reliably well for events as old as the 1950s. © 2024 Elsevier B.V.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-85176379371,

title = {Application of the ITA approach to analyze spatio-temporal trends in monthly maximum rainfall categories in the Vu Gia-Thu Bon, Vietnam},

author = { A. Karmaoui and A. Elouissi and E.B. Łupikasza and Q.B. Pham and A. Harizia and S. Fellah},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85176379371&doi=10.1007%2fs00704-023-04702-y&partnerID=40&md5=2954080a508885781fc4ccb95f4e5e3b},

doi = {10.1007/s00704-023-04702-y},

issn = {0177798X},

year  = {2024},

date = {2024-01-01},

journal = {Theoretical and Applied Climatology},

volume = {155},

number = {2},

pages = {1467-1491},

publisher = {Springer},

abstract = {This study aims to investigate the trend behavior of monthly maximum in daily rainfall categories in the Vu Gia-Thu Bon river basin located in central Vietnam. Daily maximum rainfall series from 12 rainfall stations for the period 1979–2018 were utilized to characterize six categories of the intensity of daily maximum rainfall: light (0–4 mm/day; category A), mild-moderate (4–16 mm/day; category B), moderate-heavy (16–32 mm/day; category C1), heavy (32–64 mm/day; category C2), heavy-torrential (64–128 mm/day; category D1), and torrential (≥ 128 mm/day; category D2). The new approach of the Innovative Trends Analysis was then applied to the six classified categories. The results revealed that category B had a dominant increasing trend (32% of rain events) for all the stations in January (5.85%) and February (3.44%). In March and April, category A was dominant with 45% and 20%, respectively. In July, category C1 was dominant with 25%, while in August and September, category C2 prevailed over all stations with 45% (all stations) and 20%, respectively. The categories D1 and D2 were observed at all stations in December and November, with 26% and 31% of events, respectively. These results indicate an increasing trend in the categories B, C1, C2, and D1. © 2023, The Author(s).},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-85183197407,

title = {Spatiotemporal Changes in and Driving Factors of Potential Evapotranspiration in a Hyper-Arid Locale in the Hami Region, China},

author = { Yu. Lu and L. Sun and Ch. Li and J. He and Z. Guo and Li. Duan and Ji. Zhang and E.B. Łupikasza and I. Malik and M. Wistuba and Ya. Yu},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85183197407&doi=10.3390%2fatmos15010136&partnerID=40&md5=ecb53d3e83ab408b66a789f561e3264b},

doi = {10.3390/atmos15010136},

issn = {20734433},

year  = {2024},

date = {2024-01-01},

journal = {Atmosphere},

volume = {15},

number = {1},

publisher = {Multidisciplinary Digital Publishing Institute (MDPI)},

abstract = {Potential evapotranspiration (PET) is a crucial variable for implementing adaptation measures to mitigate the potential impacts of climate change on water resources. In the context of global warming, PET is essential for predicting water resource supply and demand, guiding irrigation and water management decisions. However, there is limited understanding of the spatiotemporal changes in PET and its driving factors in the hyper-arid regions of Northwest China. In this study, the Hargreaves model was employed to estimate PET in the Hami region from 1991 to 2020. By combining relevant climate data and partial correlation analysis, we investigated the spatiotemporal distribution patterns of PET within the study area and analyzed the factors influencing these patterns. The results showed the following: (1) From 1991 to 2020, the overall PET in the Hami region demonstrated a tendency to rise. The interannual trend rates of PET for the full year, spring, summer, autumn, and winter were 0.933, 2.744, 0.906, 0.488, and −0.406 mm·a-1, respectively. Despite a decreasing trend in winter PET, the other seasonal PET values and the annual PET values exhibited an increasing trend. (2) The spatial distribution of both annual and seasonal PET showed significant regional heterogeneity, following a consistent pattern marked by lower values in the central part and higher values in the surrounding areas. The southern region tended to have relatively high PET, while the northwestern region experienced comparatively low PET. (3) Partial correlation analysis indicated significant differences in the impact of various climatic factors on PET. The maximum temperature emerged as the dominant factor influencing annual PET variation, while precipitation played a leading role in influencing autumn PET variation. This study underscores the influence of climate change on PET in the Hami region, contributing to an enhanced comprehension of PET variations. © 2024 by the authors.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-85177739337,

title = {Changes in the surface urban heat island between 1986 and 2021 in the polycentric Górnośląsko-Zagłębiowska Metropolis, southern Poland},

author = { A. Renc and E.B. Łupikasza},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85177739337&doi=10.1016%2fj.buildenv.2023.110997&partnerID=40&md5=a454377e4a071947e8e518594ac0847a},

doi = {10.1016/j.buildenv.2023.110997},

issn = {03601323},

year  = {2024},

date = {2024-01-01},

journal = {Building and Environment},

volume = {247},

publisher = {Elsevier Ltd},

abstract = {Progressing urbanization forces urban infrastructure development and leads to an increase in artificial impervious surfaces that directly contribute to changes in surface urban heat island (SUHI) in cities. This study discusses spatial and temporal changes in the SUHI extent and intensity in the biggest Metropoly in Southern Poland in summer between 1986 and 2021. The study is based on Landsat satellite images, demographic and land cover data from 1990 to 2018 from CORINE Land Cover (CLC) classifications. The comparison of satellite images recorded in different years, on similar dates and under similar meteorological conditions revealed an increase in the SUHI extent from 0.6 to 4.3 % between 1986 and 2021 due to increase in the share of impervious areas. Moreover, regardless of changes in spatial extent, the mean land surface temperature (LST) of all types of land cover increased, which may be related to recent warming. In the research period, permanent surface heat island covered 0.85 % of the GZM, and over 50 % of its area was located only within four cities. Although the mean LST for SUHI increased, the SUHI intensity decreased due to increased LST of the cold island. The SUHI extent was more related to the inhabitant number (correlation: 0.83 to 0.98) than population density (0.39–0.58). SUHI expansion in combination with recent warming of climate is a particularly negative effect where society is ageing, like in GZM. © 2023 The Author(s)},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-85177762073,

title = {Classification of precipitation types in Poland using machine learning and threshold temperature methods},

author = { Q.B. Pham and E.B. Łupikasza and M. Łukasz},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85177762073&doi=10.1038%2fs41598-023-48108-2&partnerID=40&md5=49a0c8d809885b855aecc51d029b2214},

doi = {10.1038/s41598-023-48108-2},

issn = {20452322},

year  = {2023},

date = {2023-01-01},

journal = {Scientific Reports},

volume = {13},

number = {1},

publisher = {Nature Research},

abstract = {The phase in which precipitation falls—rainfall, snowfall, or sleet—has a considerable impact on hydrology and surface runoff. However, many weather stations only provide information on the total amount of precipitation, at other stations series are short or incomplete. To address this issue, data from 40 meteorological stations in Poland spanning the years 1966–2020 were utilized in this study to classify precipitation. Three methods were used to differentiate between rainfall and snowfall: machine learning (i.e.; Random Forest), daily mean threshold air temperature, and daily wet bulb threshold temperature. The key findings of this study are: (i) the Random Forest (RF) method demonstrated the highest accuracy in rainfall/snowfall classification among the used approaches, which spanned from 0.90 to 1.00 across all stations and months; (ii) the classification accuracy provided by the mean wet bulb temperature and daily mean threshold air temperature approaches were quite similar, which spanned from 0.86 to 1.00 across all stations and months; (iii) Values of optimized mean threshold temperature and optimized wet bulb threshold temperature were determined for each of the 40 meteorological stations; (iv) the inclusion of water vapor pressure has a noteworthy impact on the RF classification model, and the removal of mean wet bulb temperature from the input data set leads to an improvement in the classification accuracy of the RF model. Future research should be conducted to explore the variations in the effectiveness of precipitation classification for each station. © 2023, The Author(s).},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-85166652818,

title = {Mass movement susceptibility prediction and infrastructural risk assessment (IRA) using GIS-based Meta classification algorithms},

author = { S.A. Ali and M. Mohajane and F. Parvin and A. Varasano and S. Hitouri and E.B. Łupikasza and Q.B. Pham},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85166652818&doi=10.1016%2fj.asoc.2023.110591&partnerID=40&md5=58888d318882f849f31265878fcfc057},

doi = {10.1016/j.asoc.2023.110591},

issn = {15684946},

year  = {2023},

date = {2023-01-01},

journal = {Applied Soft Computing},

volume = {145},

publisher = {Elsevier Ltd},

abstract = {In mountainous areas, mass movements are among the most dangerous natural hazards. Infrastructure is a crucial component and is thought of as human wealth. This infrastructure is frequently impacted by mass movements, whose frequency and size are anticipated to rise in the future due to the unequal distribution of rainfall events brought on by climate change. To deal with the anticipated repercussions, the study area, the Northern part of Morocco, needs to implement new management and maintenance practices. Thus, the main motivation of this study was to examine the mass movement vulnerability and assess risk on infrastructures in two provinces of North Morocco, i.e. Chefchaouen and Tetouan. The present study employed Reduced Error Pruning Tree (REPTree) and its ensemble with Bagging, AdaBoost, and Random SubSpace (i.e. REPTreeBagging; REPTreeAdaBoost; and REPTreeRandomSubSpace) for mass movement susceptibility mapping (MMSM) based on a comprehensive dataset of 100 mass movements locations which include debris flow, landslide, and rock fall during past 20 years (2000–2020) as well as 12 MM conditioning factors. The result revealed that REPTreeRandomSubSpace is the most viable model for MMSM with AUC = 0.8656. In addition, REPTreeBagging, REPTreeAdaBoost, and REPTree models also offer acceptable results with AUC of 0.8338, 0.8269, and 0.7942, respectively. After MMSM, the infrastructural risk was assessed and the result showed that among the six infrastructural features considered, buildings and forests have a greater risk of mass movement in the study area. Most of the mass movement and infrastructural risk-prone areas are found in the central and north-eastern parts of the study area. The results further revealed that elevation, land use, lithology, rainfall, and distance from roads are important variables for mass movement and infrastructure risk assessment (IRA). The results of this study offer a systematic sight for decision-makers to mitigate natural disasters and infrastructural risk in the study region. © 2023 Elsevier B.V.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-85149245535,

title = {Fatalities related to sudden meteorological events across Central Europe from 2010 to 2020},

author = { W. Pilorz and I. Laskowski and A. Surowiecki and E.B. Łupikasza},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85149245535&doi=10.1016%2fj.ijdrr.2023.103622&partnerID=40&md5=257d4ac4e4c96df3b84c23e9a57e5dc1},

doi = {10.1016/j.ijdrr.2023.103622},

issn = {22124209},

year  = {2023},

date = {2023-01-01},

journal = {International Journal of Disaster Risk Reduction},

volume = {88},

publisher = {Elsevier Ltd},

abstract = {Under current climate change, severe weather impacts human life in Central Europe, which is a relatively safe climate zone concerning the occurrence of the most violent weather events. This impact is projected to increase due to ongoing climate change. Therefore, this study, for the first time, discusses the death toll related to selected sudden severe weather phenomena in Central Europe in the 2010–2020 period with particular attention put to the death circumstances caused by the severe weather fatality, and their spatial and temporal distribution. In this study, severe wind, severe rainfall, lightning strikes, tornadoes and avalanches are considered. The data on phenomena occurrence were taken from the verified European Severe Weather Database. The study revealed that an average of 73 people died per year, and 365 people were hurt annually due to severe weather in the study period. Avalanches were found to be the deadliest phenomena, followed by severe wind, lightning and heavy rain. The majority of victims were killed during outdoor activities, such as spending free time outside or driving; however, the dominating death circumstances varied within the analysed domain and were different than those in the other regions of the world. This findings should be taken into account while creating national early-warning systems and better gathering severe weather impact data. Education and raising society awareness according to our results should be implemented as well. © 2023 Elsevier Ltd},

note = {2},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-85144949464,

title = {Trends in the indices of precipitation phases under current warming in Poland, 1966–2020},

author = { E.B. Łupikasza and Ł. Małarzewski},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85144949464&doi=10.1016%2fj.accre.2022.11.012&partnerID=40&md5=1fa3c6cb89f4b289e6f357650948967e},

doi = {10.1016/j.accre.2022.11.012},

issn = {16749278},

year  = {2023},

date = {2023-01-01},

journal = {Advances in Climate Change Research},

volume = {14},

number = {1},

pages = {97-115},

publisher = {KeAi Communications Co.},

abstract = {In Poland the phase in which precipitation occurs impacts the availability of water in its reservoirs, the potential for hydrological droughts, snowfall flooding and winter recreation. The influence of warming on the occurrence of precipitation phases on the Polish scale has not been studied so far. Based on data from 42 synoptic stations for the period 1966–2020, this study discusses trends in the indices of liquid (Lq), mixed (Mx) and solid (Sd) precipitation describing their totals (T), frequencies (Nd) and contribution to overall precipitation totals (T%) and a number of days with overall precipitation (Nd%) from a seasonal perspective. Moreover, the influence of seasonal and daily air temperatures on long-term variability in the precipitation phase indices was assessed. The precipitation phase was discriminated based on the observations of weather phenomena noted as current and past weather considering days with precipitation ≥ 0.1 mm. Precipitation phases significantly reacted to current warming. The strongest and widespread were increasing trends in rains (+1.74 for LqNd; +5.35 mm for LqT; +3.51% for LqNd%; +4.08% for LqT% per decade) and decreasing trends in snowfalls (−1.92 for SdNd; −3.12 mm for SdT; −3.65% for SdNd%; −3.26% for SdT% per decade) in winter when the warming was weakest but average temperature was close to freezing point. In winter, air temperature explained 60%–80% of the variance in the frequency of snowfall and rainfall. Daily air temperature > –2 °C contributed to trends in winter rainfall while daily air temperature > 1 °C most contributed to trends in winter snowfall. No trends in winter mixed precipitation were due to opposite changes in its frequency above and below 1 °C. In spring, the increase in a liquid phase was due more to the melting of a solid and mixed phase, while in autumn, it was due more to the transformation of a mixed phase into a liquid phase. In spring, air temperature explained at most 30%–50% of the variance in the indices of snowfall frequency. Negative trends in mixed precipitation were significant in transitional seasons, being more prominent in spring than in autumn and were mostly driven by changes in daily air temperatures between 0 and 5 °C. A diminished percentage of summer rains on days with air temperatures below 15 °C was compensated by their increase above that threshold thus producing no long-term trends. Warming significantly weakened the relationships between precipitation phases and average seasonal air temperatures except for summer rainfalls. © 2022 The Authors},

note = {3},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-85134892555,

title = {Spatial structure of the surface heat and cold islands in summer based on Landsat 8 imagery in southern Poland},

author = { A. Renc and E.B. Łupikasza and M. Błaszczyk},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85134892555&doi=10.1016%2fj.ecolind.2022.109181&partnerID=40&md5=f6cb511e4e46bc5cba0f14cf0909725d},

doi = {10.1016/j.ecolind.2022.109181},

issn = {1470160X},

year  = {2022},

date = {2022-01-01},

journal = {Ecological Indicators},

volume = {142},

publisher = {Elsevier B.V.},

abstract = {The intense development of cities and related replacement of vegetated areas with impervious surfaces contributed to the intensification of the urban heat island effect, which is a hazardous phenomenon for humans. In this study, the spatial structure of the surface heat and cold island (SHI and SCI; respectively) in the Górnośląsko-Zagłębiowska Metropolis (GZM), the most urbanized and populated area in Poland, is investigated using four Landsat 8 satellite images recorded in the summers between 2015 and 2019. The satellite images processed to the land surface temperature (LST) and the Corine Land Cover 2018 (CLC 2018) classification were used to calculate indicators of the spatial extent and intensity of SHI and SCI. Their spatial extents in the GZM ranged from 15.4 to 16.4% and 12.2–19.4%, respectively, depending on the analyzed days with a large percentage of the agricultural areas within the SHI boundaries. Therefore, an original approach to delineate the surface urban heat island (SUHI) is proposed. This approach reduced the extent of the GZM SHI by 2.9 to 2.0%, depending on the day. In the GZM, more than 70% of the SHI consisted of discontinuous urban fabric and industrial or commercial units. Heat island indices recognized the spatial structure of SUHI as an archipelago. Vegetation and crops constituted 90% of the SCI, and these land cover types explained most of the SCI variability over time compared to the SHI. The vegetation expanded, and its characteristics continually changed during the summer season. Moreover, vegetation was more sensitive to changes in meteorological conditions than impervious surfaces. The LST was most strongly correlated with the percentage share of artificial areas in the GZM districts. In turn, the correlations between LST and forest and semi natural areas were much weaker when precipitation occurred before the recording of satellite images. The intensity of SUHI in the GZM ranged from approximately 5 to 9 °C depending on the date and the method of identifying urban and nonurban areas. © 2022 The Author(s)},

note = {1},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-85127604255,

title = {Flood vulnerability and buildings’ flood exposure assessment in a densely urbanised city: comparative analysis of three scenarios using a neural network approach},

author = { Q.B. Pham and S.A. Ali and E. Bielecka and B. Calka and A. Orych and F. Parvin and E.B. Łupikasza},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85127604255&doi=10.1007%2fs11069-022-05336-5&partnerID=40&md5=3f672a3aa225c24656490d62d9f2b9ef},

doi = {10.1007/s11069-022-05336-5},

issn = {0921030X},

year  = {2022},

date = {2022-01-01},

journal = {Natural Hazards},

volume = {113},

number = {2},

pages = {1043-1081},

publisher = {Springer Science and Business Media B.V.},

abstract = {Advances in the availability of multi-sensor, remote sensing-derived datasets, and machine learning algorithms can now provide an unprecedented possibility to predict flood events and risk. Therefore, this study was undertaken to develop a flood vulnerability map and to assess the exposure of buildings to flood risk in Warsaw, the capital of Poland. This goal was pursued in four research phases. The thirteen flood predictors were evaluated using information gain ratio (IGR), and finally reduced to eight of the most causative ones and used for flood vulnerability mapping with three machine learning algorithms, Artificial Neural Network Multi-Layer Perceptron (ANN/MLP), Deep Learning Neural Network based approach—DL4j (DLNN-DL4j) and Bayesian Logistic Regression (BLR). These algorithms show a good predictive performance with the receiver operating curve (ROC) value of 0.851, 0.877 and 0.697, respectively. The buildings’ exposure to flood was assessed in line with criteria established in European and national legal regulations. The introduced new buildings' flood hazard index (BFH) revealed a significant similarity of potential flood risk for both models, highlighting the greatest risk in zones with high vulnerability to flooding. Depending on the method used, the BFH value was 0.54 (ANN), 0.52 (DLNNs) or 0.64 (BLR). The holistic approach proposed in this study could assist local authorities in improving flood management. © 2022, The Author(s), under exclusive licence to Springer Nature B.V.},

note = {12},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-85128565284,

title = {Large hail detection using radar-based VIL calibrated with isotherms from the ERA5 reanalysis},

author = { W. Pilorz and M. Zięba and J. Szturc and E.B. Łupikasza},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85128565284&doi=10.1016%2fj.atmosres.2022.106185&partnerID=40&md5=aba4919ab18511ef4c9acb3d15983347},

doi = {10.1016/j.atmosres.2022.106185},

issn = {01698095},

year  = {2022},

date = {2022-01-01},

journal = {Atmospheric Research},

volume = {274},

publisher = {Elsevier Ltd},

abstract = {Hail involving very large hailstones (maximum diameter ≥ 4 cm) is rare but is one of the most hazardous weather phenomena in Poland. The most useful of the numerous weather radar reflectivity indicators are automated hail detection algorithms and reflectivity criteria, which can be easily implemented in operational weather warning systems. Since the temperature at which large hail forms is known, the vertically integrated liquid water content (VIL) can be calculated for the corresponding temperature layer. This paper presents four new VIL-based hail indicators using hail formation temperatures determined by the isotherms from ERA5. We compared these indicators with the 8 km Constant Altitude Plan Position Indicator (CAPPI) and the Waldvogel hail detection method by linking the detected cells to ESWD reports. Based on the VILs, we aimed to determine which layer within the VIL integration was the most useful for large hail prediction. In the case of the VILs, the layer between −12 and −25 °C was the best for hail detection. We also analysed the lead times of these indicators to assess their potential for implementation in the operational warning system in Poland. Using data from the European Severe Weather Database and the Polish radar system, we found that most incidents involving very large hailstones were linked to supercell storms with distinctive reflectivity signatures. The best hail indicator was the Waldvogel et al. (1979) hail detection technique, which had a lead time of approximately 17,5 min. The VIL had a near-zero lead time. © 2022 Elsevier B.V.},

note = {3},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-85123513031,

title = {Relationships between Vertical Temperature Gradients and PM10 Concentrations during Selected Weather Conditions in Upper Silesia (Southern Poland)},

author = { E.B. Łupikasza and T. Niedźwiedź},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85123513031&doi=10.3390%2fatmos13010125&partnerID=40&md5=dd4b30d9c82a347b1ca0f373a2edad92},

doi = {10.3390/atmos13010125},

issn = {20734433},

year  = {2022},

date = {2022-01-01},

journal = {Atmosphere},

volume = {13},

number = {1},

publisher = {MDPI},

abstract = {This paper studies surface air temperature inversions and their impact on air pollution under the background of meteorological conditions in southern Poland. The relationship of temperature gradients and air quality classes with weather conditions in the most urbanized and polluted part of Poland as represented by the Upper Silesia region (USR) within the administrative boundaries of the Górnośląsko-Zagłębiowska Metropolis (GZM) is presented. Based on probability analysis this study hierarchized the role of the selected weather elements in the development of surface-based temperature inversion (SBI) and air quality (AQ). The thresholds of weather elements for a rapid increase in the probability of oppressive air pollution episodes were distinguished. Although most SBI occurred in summer winter SBIs were of great importance. In that season a bad air quality occurred during >70% of strong inversions and >50% of moderate inversions. Air temperature more strongly triggered AQ than SBI development. Wind speed was critical for SBI and significant for AQ development. A low cloudiness favored SBI occurrence altered air quality in winter and spring during SBI and favored very bad AQ5 (>180 µg/m3) occurrence. The probability of high air pollution enhanced by SBI rapidly increased in winter when the air temperature dropped below −6 °C the wind speed decreased below 1.5 m/s and the sky was cloudless. Changes in the relative humidity did not induce rapid changes in the occurrence of bad AQ events during SBI. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.},

note = {3},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-85107339961,

title = {Evaluation of acidogenesis products’ effect on biogas production performed with metagenomics and isotopic approaches},

author = { A. Detman and M. Bucha and L. Treu and A. Chojnacka and Ł. Pleśniak and A. Salamon and E.B. Łupikasza and R. Gromadka and J. Gawor and A. Gromadka and W. Drzewicki and M. Jakubiak and M. Janiga and I. Matyasik and M.K. Błaszczyk and M.O. Jędrysek and S. Campanaro and A. Sikora},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85107339961&doi=10.1186%2fs13068-021-01968-0&partnerID=40&md5=874a262863a4c7bc7faf512bf08736a6},

doi = {10.1186/s13068-021-01968-0},

issn = {17546834},

year  = {2021},

date = {2021-01-01},

journal = {Biotechnology for Biofuels},

volume = {14},

number = {1},

publisher = {BioMed Central Ltd},

abstract = {Background: During the acetogenic step of anaerobic digestion, the products of acidogenesis are oxidized to substrates for methanogenesis: hydrogen, carbon dioxide and acetate. Acetogenesis and methanogenesis are highly interconnected processes due to the syntrophic associations between acetogenic bacteria and hydrogenotrophic methanogens, allowing the whole process to become thermodynamically favorable. The aim of this study is to determine the influence of the dominant acidic products on the metabolic pathways of methane formation and to find a core microbiome and substrate-specific species in a mixed biogas-producing system. Results: Four methane-producing microbial communities were fed with artificial media having one dominant component, respectively, lactate, butyrate, propionate and acetate, for 896 days in 3.5-L Up-flow Anaerobic Sludge Blanket (UASB) bioreactors. All the microbial communities showed moderately different methane production and utilization of the substrates. Analyses of stable carbon isotope composition of the fermentation gas and the substrates showed differences in average values of δ13C(CH4) and δ13C(CO2) revealing that acetate and lactate strongly favored the acetotrophic pathway, while butyrate and propionate favored the hydrogenotrophic pathway of methane formation. Genome-centric metagenomic analysis recovered 234 Metagenome Assembled Genomes (MAGs), including 31 archaeal and 203 bacterial species, mostly unknown and uncultivable. MAGs accounted for 54%–67% of the entire microbial community (depending on the bioreactor) and evidenced that the microbiome is extremely complex in terms of the number of species. The core microbiome was composed of Methanothrix soehngenii (the most abundant), Methanoculleus sp., unknown Bacteroidales and Spirochaetaceae. Relative abundance analysis of all the samples revealed microbes having substrate preferences. Substrate-specific species were mostly unknown and not predominant in the microbial communities. Conclusions: In this experimental system, the dominant fermentation products subjected to methanogenesis moderately modified the final effect of bioreactor performance. At the molecular level, a different contribution of acetotrophic and hydrogenotrophic pathways for methane production, a very high level of new species recovered, and a moderate variability in microbial composition depending on substrate availability were evidenced. Propionate was not a factor ceasing methane production. All these findings are relevant because lactate, acetate, propionate and butyrate are the universal products of acidogenesis, regardless of feedstock. © 2021, The Author(s).},

note = {5},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-85114629031,

title = {Surface-based nocturnal air temperature inversions in southern Poland and their influence on PM10 and PM2.5 concentrations in Upper Silesia},

author = { T. Niedźwiedź and E.B. Łupikasza and Ł. Małarzewski and T. Budzik},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85114629031&doi=10.1007%2fs00704-021-03752-4&partnerID=40&md5=c91730def2b51bffd8c49199b853400d},

doi = {10.1007/s00704-021-03752-4},

issn = {0177798X},

year  = {2021},

date = {2021-01-01},

journal = {Theoretical and Applied Climatology},

volume = {146},

number = {3-4},

pages = {897-919},

publisher = {Springer},

abstract = {The frequency, strength and seasonal variations of surface-based temperature inversions (SBTIs) in Upper Silesia (Southern Poland) were examined using data from January 2001 to September 2020. Based on the air temperatures recorded at the meteorological station of the Institute of Earth Sciences in Sosnowiec (263 m a.s.l.) at heights of 2 m and 88 m above the ground, the vertical temperature gradient of the 100-m layer (γSos100 m) was determined. A lapse rate of γSos100 m > 0.5 K was defined as a temperature inversion. The measurements for 00 UTC (midnight) and 12 UTC (midday) were compared with data from the upper air station in Wrocław (116 m a.s.l.) located in the Lower Silesia Lowland, approximately 170 km NW of Sosnowiec. Based on soundings from Wrocław, in addition to the temperature gradient in the lower 100-m layer of air (γWrc100), three other characteristics of SBTIs were calculated: inversion depth (ID) or thickness in metres, inversion strength (ΔTi) in K and vertical temperature gradients across the whole SBTI layer γi in K 100 m−1. On an annual basis, the frequency of nighttime SBTIs (γ > 0.5 K 100 m−1) ranged from 47% in Sosnowiec to almost 59% in Wrocław. At both stations, the fewest SBTIs occurred in winter (23–38%) and the most in summer (64–75%). Moreover, they were more frequent in spring (52–61%) than in autumn (49–59%). The SBTI frequency was very low during the midday hours, amounting to 0.6–0.7% days a year, and it increased to 1–2% only in winter. Annually, the depth of 81% of inversions ranged between 50 and 300 m, varying seasonally from almost 67% in winter to 87% in summer. The presented research shows that SBTIs in winter were among the main factors contributing to a high concentration of particulate matter pollutants in the ground-level atmosphere. During nights with temperature inversions, the annual mean PM10 concentration reached 125% of the mean value, ranging from 114% in summer to 189% in winter. © 2021, The Author(s).},

note = {4},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-85101490448,

title = {Importance of regional indices of atmospheric circulation for periods of warming and cooling in Svalbard during 1920–2018},

author = { E.B. Łupikasza and T. Niedźwiedź and R. Przybylak and Ø. Nordli},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85101490448&doi=10.1002%2fjoc.7031&partnerID=40&md5=ae94374bbd4fe70112fed2628f319e21},

doi = {10.1002/joc.7031},

issn = {08998418},

year  = {2021},

date = {2021-01-01},

journal = {International Journal of Climatology},

volume = {41},

number = {6},

pages = {3481-3502},

publisher = {John Wiley and Sons Ltd},

abstract = {The Arctic has experienced prominent climate warming, at the beginning of the 20th century and currently. Comparing the driving mechanism during these periods helps to explain the causes of contemporary climate change. Our study explores the impact of regional circulation on Svalbard's surface air temperature (SAT; 2 m above ground). We used air temperature data from Svalbard Airport, Bjørnøya stations, and three regional circulation indices that describe the frequency of cyclonic conditions, zonal circulation, and meridional circulation. The indices were calculated for four circulation areas with differing circulation conditions and, therefore, may have various impacts on long-term changes in SAT. This was checked for the entire study period (1920–2018), and 30-year sub-periods representing the most prominent climatic events: the early 20th-century Arctic warming (ETCAW), contemporary Arctic warming (CAW), and a cold period between them (CAP). In autumn and winter, the deviations in SAT from the long-term average during warm and cold periods were almost twice as large at Svalbard Airport as at Bjørnøya. In these seasons, the ETCAW was significantly warmer than the subsequent cold period, which was not the case for summer and spring. However, long-term trends in the regional circulation indices were more evident in summer and spring than in autumn and winter. Air temperature was the most strongly influenced by meridional circulation over the eastern circulation areas, with the exception of spring, when air temperature variability was more affected by zonal circulation. The recent warming weakened the relationship between SAT and the indices in summer. We attributed the ETCAW in autumn to a southerly advection of sensible heat. During the same historical period, the impact of the indices was much weaker in winter. In winter during the CAP, there was a higher frequency of northern air advection, particularly over the northern part of the Greenland Sea. © 2021 Royal Meteorological Society},

note = {1},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-85099732938,

title = {Dynamics and Complexity of Dark Fermentation Microbial Communities Producing Hydrogen From Sugar Beet Molasses in Continuously Operating Packed Bed Reactors},

author = { A. Detman and D. Laubitz and A. Chojnacka and E. Wiktorowska-Sowa and J. Piotrowski and A. Salamon and W. Kaźmierczak and M.K. Błaszczyk and A. Barberan and Y. Chen and E.B. Łupikasza and F. Yang and A. Sikora},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85099732938&doi=10.3389%2ffmicb.2020.612344&partnerID=40&md5=72d4f1089fb0c86add3703194bc62280},

doi = {10.3389/fmicb.2020.612344},

issn = {1664302X},

year  = {2021},

date = {2021-01-01},

journal = {Frontiers in Microbiology},

volume = {11},

publisher = {Frontiers Media S.A.},

abstract = {This study describes the dynamics and complexity of microbial communities producing hydrogen-rich fermentation gas from sugar-beet molasses in five packed-bed reactors (PBRs). The bioreactors constitute a part of a system producing hydrogen from the by-products of the sugar-beet industry that has been operating continuously in one of the Polish sugar factories. PBRs with different working volumes, packing materials, construction and inocula were tested. This study focused on analysis (based on 16S rRNA profiling and shotgun metagenomics sequencing) of the microbial communities selected in the PBRs under the conditions of high (>100 cm3/g COD of molasses) and low (<50 cm3/g COD of molasses) efficiencies of hydrogen production. The stability and efficiency of the hydrogen production are determined by the composition of dark fermentation microbial communities. The most striking difference between the tested samples is the ratio of hydrogen producers to lactic acid bacteria. The highest efficiency of hydrogen production (130–160 cm3/g COD of molasses) was achieved at the ratios of HPB to LAB ≈ 4:2.5 or 2.5:1 as determined by 16S rRNA sequencing or shotgun metagenomics sequencing, respectively. The most abundant Clostridium species were C. pasteurianum and C. tyrobutyricum. A multiple predominance of LAB over HPB (3:1–4:1) or clostridia over LAB (5:1–60:1) results in decreased hydrogen production. Inhibition of hydrogen production was illustrated by overproduction of short chain fatty acids and ethanol. Furthermore, concentration of ethanol might be a relevant marker or factor promoting a metabolic shift in the DF bioreactors processing carbohydrates from hydrogen-yielding toward lactic acid fermentation or solventogenic pathways. The novelty of this study is identifying a community balance between hydrogen producers and lactic acid bacteria for stable hydrogen producing systems. The balance stems from long-term selection of hydrogen-producing microbial community, operating conditions such as bioreactor construction, packing material, hydraulic retention time and substrate concentration. This finding is confirmed by additional analysis of the proportions between HPB and LAB in dark fermentation bioreactors from other studies. The results contribute to the advance of knowledge in the area of relationships and nutritional interactions especially the cross-feeding of lactate between bacteria in dark fermentation microbial communities. © Copyright © 2021 Detman, Laubitz, Chojnacka, Wiktorowska-Sowa, Piotrowski, Salamon, Kaźmierczak, Błaszczyk, Barberan, Chen, Łupikasza, Yang and Sikora.},

note = {6},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-85089820782,

title = {Seasonal and vertical variability of saccharides and other organic tracers of PM10 in relation to weather conditions in an urban environment of Upper Silesia, Poland},

author = { L. Marynowski and E.B. Łupikasza and K. Dąbrowska-Zapart and Ł. Małarzewski and T. Niedźwiedź and B.R.T. Simoneit},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85089820782&doi=10.1016%2fj.atmosenv.2020.117849&partnerID=40&md5=d0c65b4e064f6a3a076cab7996c52eda},

doi = {10.1016/j.atmosenv.2020.117849},

issn = {13522310},

year  = {2020},

date = {2020-01-01},

journal = {Atmospheric Environment},

volume = {242},

publisher = {Elsevier Ltd},

abstract = {PM10 samples collected over one year from the city of Sosnowiec, part of the Upper Silesia metropolis were studied. The locale was a gradient meteorological station, 4 m and 100 m above ground. The dominant compounds identified were anhydro-, mono- and disaccharides which were divided into three groups of organic tracers (OT): biomass burning (BB) including low-rank coal burning, pollen grains (PG) and fungal spores (FS). The BB group included: levoglucosan, mannosan and galactosan, complemented with vanillic and dehydroabietic acids. The PG group included: fructose, glucose and sucrose, supplemented with D-pinitol, and the FS tracers included: arabitol, mannitol and trehalose. Levoglucosan reached 1503 ng/m3 in heating season at 4 m and 983 ng/m3 at 100 m. These values are among the highest mean concentrations of levoglucosan reported in Europe, confirming severe pollution of the Upper Silesian urban environment. We also suggest that the significant levoglucosan levels during the non-heating seasons could be from wind advected polluted soil and dust. All FS tracers correlate well with fungal spore counts, while the correlation of pollen numbers with their typical molecular tracers is statistically less significant. Weather conditions significantly influence the concentration of OT in aerosols. Among these, air temperature is a factor that affects the occurrence/existence of OT in the atmosphere, while temperature inversions are the main phenomenon which determines elevated concentrations of pollutants and their vertical variation in ambient air. For example, the concentration of BB tracers can be twice as high at 4 m as at 100 m under moderate to strong temperature inversions associated with low wind speed. Water vapor pressure and sun irradiation are also important factors controlling OT concentrations. This is one of the first studies of vertical differences in organic tracers which presents the variability and complexity of the processes affecting their concentrations in ambient air. © 2020 Elsevier Ltd},

note = {7},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-85093499822,

title = {Radar reflectivity signatures and possible lead times of warnings for very large hail in Poland based on data from 2007-2015},

author = { W. Pilorz and E.B. Łupikasza},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85093499822&doi=10.2478%2fenviron-2020-0016&partnerID=40&md5=41638206bafcd2cd37b9c3e327d860f8},

doi = {10.2478/environ-2020-0016},

issn = {23540079},

year  = {2020},

date = {2020-01-01},

journal = {Environmental and Socio-Economic Studies},

volume = {8},

number = {3},

pages = {34-47},

publisher = {De Gruyter Open Ltd},

abstract = {Hail involving very large hailstones (maximum diameter ≥ 5 cm), is a rare but very hazardous phenomenon in Poland, and can be forecast using reflectivity signatures. Every year, Poland experiences from one to over a dozen storms with such large hailstones. Despite the current recommendations regarding polarimetric techniques used in hail risk monitoring, Poland does not have a fully polarimetric radar network. Therefore it is essential to check hail detection capabilities using only reflectivity techniques based on individual radar systems involving hail detection algorithms such as Waldvogel et al. (1979) or Vertically Integrated Liquid thresholds connected with manual signature analysis to get better warning decisions. This study is aimed to determine the reflectivity features, thresholds and lead times for nowcasting of severe storms with very large hailstones in Poland, using data from the Polish radar system and from the European Severe Weather Database for the period 2007-2015. Most incidents involving very large hailstones were linked to supercell storms with distinctive reflectivity signatures, however, some storms with extremely large hailstones presented very poorly developed signatures. These signatures enabled the prediction of hail involving very large hailstones approximately 29 minutes before it fell. The Lemon (1980) criterion and WER were found to be the best hail predictors for Polish radar system conditions. © 2020 Copyright by University of Silesia in Katowice.},

note = {1},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-85080869761,

title = {Changing probabilities of days with snow and rain in the atlantic sector of the arctic under the current warming trend},

author = { E.B. Łupikasza and K. Cielecka-Nowak},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85080869761&doi=10.1175%2fJCLI-D-19-0384.1&partnerID=40&md5=eb00b659f59b605fdb799005d6dc414e},

doi = {10.1175/JCLI-D-19-0384.1},

issn = {08948755},

year  = {2020},

date = {2020-01-01},

journal = {Journal of Climate},

volume = {33},

number = {7},

pages = {2509-2532},

publisher = {American Meteorological Society},

abstract = {Trends in the probabilities of days with liquid, solid, and mixed precipitation are discussed on annual and intra-annual scales along with their relationship to air temperature in the Atlantic sector of the Arctic. Data on weather phenomena were used to identify precipitation phases. The data cover various periods but all series extend to 2017. Trends in the annual air temperature and probability of precipitation phases for various long-term periods are discussed and differences in the mean air temperature and probability of precipitation phases between 1979-97 (insignificant warming) and 1999-2017 (significant warming) on an intra-annual scale. In the studied region, the precipitation phases were sensitive to warming and atmospheric circulation to various degrees, depending on the phase, mean climate, month, and local conditions. The probability of days with rainfall increased (by 11% to 13% per decade), whereas the probability of days with snowfall decreased (by 21.5% to 22.4% per decade). The increasing trends in the probability of rainy days at all stations and decreasing trends in the probability of snowy days in the southern part of the region were warming induced. The most significant and widespread trends in snowy and rainy days were found in September. The probability of days with mixed precipitation exhibited no trends due to an inverse reaction to warming in the warmer and colder parts of the year. Temporal variability in the probability of precipitation phases was significantly linked to three teleconnection patterns playing a role in various parts of the year. © 2020 American Meteorological Society.},

note = {3},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-85087311458,

title = {Revisiting the extended svalbard airport monthly temperature series, and the compiled corresponding daily series 1898–2018},

author = { Ø. Nordli and P. Wyszyński and H.M. Gjelten and K. Isaksen and E.B. Łupikasza and T. Niedźwiedź and R. Przybylak},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85087311458&doi=10.33265%2fpolar.v39.3614&partnerID=40&md5=9ad55d3a294f906e191e87002b9a0cba},

doi = {10.33265/polar.v39.3614},

issn = {08000395},

year  = {2020},

date = {2020-01-01},

journal = {Polar Research},

volume = {39},

pages = {1-15},

publisher = {Norwegian Polar Institute},

abstract = {The Svalbard Airport composite series spanning the period from 1898 to the present represents one of very few long-term instrumental temperature series from the High Arctic. A homogenized monthly temperature series is available since 2014. Here we increase the resolution from a monthly to daily basis, and further digitization of historical data has reduced the uncertainty of the series. The most pronounced changes in the 120-year record occur during the last three decades. For the 1991–2018 period the number of days warmer than 0 and 5 °C has increased by 25 (21%) and 22 (59%), respectively, per year compared to the 1961–1990 standard normal. Likewise, comparing the same periods, the number of days colder than −10 and −20 °C has decreased by 42 (32%) and 27 (62%), respectively. During the entire time span of the series, the western Spitsbergen climate has gone through stepwise changes, alternating between cold and warm regimes: 1899–1929 was cold, 1930–1961 warm, 1962–1998 cold and 1999–2018 warm. The latest cold regime was 1.0 °C warmer than the first cold one, and the latest warm regime was 1.7 °C warmer than the previous warm one. For the whole series the linear trend for annual means amounts to 0.32°C/decade, which is about 3.5 times the increase of the global mean temperature for the same period. Since 1991, the rate of warming at Svalbard Airport is 1.7 °C/decade, which is more than twice the Arctic average (0.8 °C/decade; north of 66 °N) and about seven times the global average for the same period. © 2020 B. Ø. Nordli et al.},

note = {23},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-85081921948,

title = {Influence of climatic conditions on growth rings of Salix uva-ursi Pursh from the southeastern shore of Hudson Bay, Subarctic Canada},

author = { M. Opała-Owczarek and P. Owczarek and E.B. Łupikasza and S. Boudreau and K. Migała},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85081921948&doi=10.1080%2f15230430.2020.1722397&partnerID=40&md5=1684d8040b73f7ce8253e01b0dd81c52},

doi = {10.1080/15230430.2020.1722397},

issn = {15230430},

year  = {2020},

date = {2020-01-01},

journal = {Arctic, Antarctic, and Alpine Research},

volume = {52},

number = {1},

pages = {87-102},

publisher = {Taylor and Francis Ltd.},

abstract = {Over the past decades, warmer air temperature and spatiotemporal changes in the amount and patterns of precipitation have been observed at high latitudes. Such interannual variability in climatic conditions has a strong influence on the dynamics of biological processes regulating terrestrial ecosystems. Dendroclimatology can improve our understanding of the impacts of climate change on vegetation. Based on ring width and frost rings of bearberry willow (Salix uva-ursi) individuals sampled on the southeastern shore of Hudson Bay, Nunavik (Subarctic Québec; Canada), we built a reliable 105-year growth chronology. A complex dendroclimatological analysis, using the standard approach (mean temperature and precipitation sums), extreme variables, and various climatological indices based on daily data, was conducted in order to precisely describe the relationship between annual variations in growth rings and climatic conditions. The growth of Low Arctic willows in the Hudson Bay region is determined by changes in air temperatures as well as precipitation during the summer. However, temperature increases and reductions in amounts of rainfall may intensify drought stress, which is unfavorable for this species. We found that analysis of daily amounts and intensity of precipitation improved our understanding of the factors conditioning the growth of the studied species in an extreme habitat. © 2020, © 2020 The Author(s). Published with license by Taylor & Francis Group, LLC.},

note = {6},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-85066886240,

title = {The Influence of Mesoscale Atmospheric Circulation on Spitsbergen Air Temperature in Periods of Arctic Warming and Cooling},

author = { E.B. Łupikasza and T. Niedźwiedź},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85066886240&doi=10.1029%2f2018JD029443&partnerID=40&md5=b34fcbebedcc45844135ec958a018bc1},

doi = {10.1029/2018JD029443},

issn = {2169897X},

year  = {2019},

date = {2019-01-01},

journal = {Journal of Geophysical Research: Atmospheres},

volume = {124},

number = {10},

pages = {5233-5250},

publisher = {Blackwell Publishing Ltd},

abstract = {The Arctic has experienced step changes in climate conditions, which are still not fully understood. Particularly intriguing was the Early Twentieth-Century Arctic Warming (ETCAW), which occurred prior to anthropogenic interference in the environment. This paper quantitatively assesses the differences in atmospheric circulation patterns during periods of warming and cooling on Spitsbergen with a particular focus on ETCAW. The patterns of atmospheric circulation were taken from the catalog of day-by-day circulation types created for Svalbard. The catalog includes 21 circulation types, assigned to every day between 1920 and 2017. The research focused on winter and autumn, the seasons exhibiting pronounced ETCAW on Spitsbergen. The long-term variability in autumn and winter air temperatures on Spitsbergen significantly depends on the frequency of air advection from clearly defined directions and reveals some seasonal differentiation. Warming was related in autumn to southern and south-eastern advection, in winter to southern advection, and in both cyclonic and anticyclonic conditions. These “warm” types explained up to 21% (September–November) or 25% (December–February) of the variability in air temperature. In winter, cooling was significantly related to anticyclonic type with air advection from the northeast (NEa: 24% of variability): in autumn to cyclonic northern (Nc) and northeastern (NEc) types. During ETCAW, the frequency of warm circulation types was significantly higher, and that of “cold” circulation types significantly lower. No relevant differences in patterns were found between ETCAW and Recent Arctic Warming; however, the frequency of warm and cold types was higher and lower, respectively, during ETCAW. © 2019. American Geophysical Union. All Rights Reserved.},

note = {9},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-85063114632,

title = {Assessing seasonal drought variations and trends over Central Europe},

author = { S. Hänsel and Z. Ustrnul and E.B. Łupikasza and P. Skalak},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85063114632&doi=10.1016%2fj.advwatres.2019.03.005&partnerID=40&md5=c800e522f3bd866001f01aa99facf35e},

doi = {10.1016/j.advwatres.2019.03.005},

issn = {03091708},

year  = {2019},

date = {2019-01-01},

journal = {Advances in Water Resources},

volume = {127},

pages = {53-75},

publisher = {Elsevier Ltd},

abstract = {The relevance of drought is still often underestimated for temperate climate regions like Central Europe that are characterized by on average ample precipitation. Nonetheless, several drought events in recent years (e.g. 1992; 2003; 2015 and 2018) demonstrated that droughts are a relevant factor for several economic activities (e.g.; agriculture; water dependent industries; energy supply; etc.) in Central Europe. This is particularly true for the vegetation period, where increasing evapotranspiration rates due to rising atmospheric temperatures are intensifying existing drought conditions that originally developed from rainfalls deficits. The contribution of this study is an assessment of the long-term variability of drought conditions and seasonal climate trends within 1951–2015 based on a collective of 91 climate stations from the national meteorological services of Germany, Poland and the Czech Republic. Using a set of eight drought and three heavy precipitation indices an aggregated evaluation of seasonal precipitation characteristics is done and the driest seasons are identified for the entire study area as well as for four sub-regions. It is shown that the choice of the study period matters (1951–2015 vs. 1961–2015) as the pronounced (multi-)decadal variability of drought conditions restricts the temporal stability of computed trends. The drought trends computed for 1951–2015 are similar in direction, but generally smaller in magnitude than those of the ten year shorter period 1961–2015, as the 1950s have been a very dry decade in Central Europe. Seasonally, drying trends were observed for spring and less pronounced for summer, while autumn and winter show wetting trends. The seasonal trends are sensitive to shifts in the season definition by one month. Vegetation period I (VP-I) shows stronger drying trends, but less increases in heavy precipitation than spring, while the drought trends are less pronounced in vegetation period II (VP-II) as compared to the summer season, but more trends towards heavy precipitation increases occur in VP-II. These differences are explained by the daily trends in the seasonal cycle that show the strongest drying in April, June and the beginning of August and the strongest wetting in March and September. Generally, heavy precipitation increases prevail over decreasing trends in all seasons, whereby stations with strong drought trends generally have smaller positive or even negative heavy precipitation trends. A simultaneous occurrence of drought and heavy precipitation increases is observed in spring at several stations, particularly in sub-region West. © 2019 The Authors},

note = {80},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-85046035095,

title = {Vertical climatic belts in the Tatra Mountains in the light of current climate change},

author = { E.B. Łupikasza and B. Szypuła},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85046035095&doi=10.1007%2fs00704-018-2489-2&partnerID=40&md5=595e6e168f3b029eaead96246b6e80a2},

doi = {10.1007/s00704-018-2489-2},

issn = {0177798X},

year  = {2019},

date = {2019-01-01},

journal = {Theoretical and Applied Climatology},

volume = {136},

number = {1-2},

pages = {249-264},

publisher = {Springer-Verlag Wien},

abstract = {The paper discusses temporal changes in the configuration of vertical climatic belts in the Tatra Mountains as a result of current climate change. Meteorological stations are scarce in the Tatra Mountains; therefore, we modelled decadal air temperatures using existing data from 20 meteorological stations and the relationship between air temperature and altitude. Air temperature was modelled separately for northern and southern slopes and for convex and concave landforms. Decadal air temperatures were additionally used to delineate five climatic belts previously distinguished by Hess on the basis of threshold values of annual air temperature. The spatial extent and location of the borderline isotherms of 6, 4, 2, 0, and − 2 °C for four decades, including 1951–1960, 1981–1990, 1991–2000, and 2001–2010, were compared. Significant warming in the Tatra Mountains, uniform in the vertical profile, started at the beginning of the 1980s and led to clear changes in the extent and location of the vertical climatic belts delineated on the basis of annual air temperature. The uphill shift of the borderline isotherms was more prominent on southern than on northern slopes. The highest rate of changes in the extent of the climatic belts was found above the isotherm of 0 °C (moderately cold and cold belts). The cold belt dramatically diminished in extent over the research period. © 2018, The Author(s).},

note = {9},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-85061674896,

title = {The role of winter rain in the glacial system on Svalbard},

author = { E.B. Łupikasza and D. Ignatiuk and M. Grabiec and K. Cielecka-Nowak and M. Laska and J.A. Jania and B. Luks and A. Uszczyk and T. Budzik},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85061674896&doi=10.3390%2fw11020334&partnerID=40&md5=d7e66db094c7e1118a1ffe687c120fdc},

doi = {10.3390/w11020334},

issn = {20734441},

year  = {2019},

date = {2019-01-01},

journal = {Water (Switzerland)},

volume = {11},

number = {2},

publisher = {MDPI AG},

abstract = {Rapid Arctic warming results in increased winter rain frequencies, which may impact glacial systems. In this paper, we discuss climatology and precipitation form trends, followed by examining the influence of winter rainfall (Oct-May) on both the mass balance and dynamics of Hansbreen (Svalbard). We used data from the Hornsund meteorological station (01003 WMO), in addition to the original meteorological and glaciological data from three measurement points on Hansbreen. Precipitation phases were identified based on records of weather phenomena and used-along with information on lapse rate-to estimate the occurrence and altitudinal extent of winter rainfall over the glacier. We found an increase in the frequency of winter rain in Hornsund, and that these events impact both glacier mass balance and glacier dynamics. However, the latter varied depending on the degree of snow cover and drainage systems development. In early winter, given the initial, thin snow cover and an inefficient drainage system, rainfall increased glacier velocity. Full-season winter rainfall on well-developed snow was effectively stored in the glacier, contributing on average to 9% of the winter accumulation. © 2019 by the authors.},

note = {16},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-85107367886,

title = {Atmospheric circulation in the investigations of the Polish climatologists [Cyrkulacja atmosferyczna w badaniach Polskich klimatologów]},

author = { T. Niedźwiedź and E.B. Łupikasza},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85107367886&doi=10.32045%2fPG-2019-004&partnerID=40&md5=6e4841d95939ce9766e1a8ed23d486d1},

doi = {10.32045/PG-2019-004},

issn = {00332135},

year  = {2019},

date = {2019-01-01},

journal = {Przeglad Geofizyczny},

volume = {64},

number = {1-2},

pages = {107-166},

publisher = {Przeglad Geofizyczny},

abstract = {This paper presents most important directions of research that were undertaken by polish climatologist in the field of synoptic climatology which analyses various forms of atmospheric circulation and their impact on climate. Initial research in the field of synoptic climatology dates back in early 20th century while fast development of the research took place after the II World War. Several classification of circulation types constituted the basis of polish synoptic climatology, including quantitative classification of circulation types and weather types by Lityński (1962; 1969), subjective typology by Osuchowska-Klein (1973; 1991), automatic classification of circulation types for Norther Hemisphere by Ustrnul (1997) and objective classification by Piotrowski (2009). „Grosswetterlagen” macroscale classification after Hess and Brezowsky (1952; 1977) for Central Europe was also used. Regional typologies include: the calendar of circulation types for Southern Poland (Niedźwiedź 1981), Lublin region (Bartoszek 2015) and for the Sudetes (Ojrzyńska 2012). The most frequently used circulation indices included: NAO, macro types of mid-tropospheric circulation developed by Russian meteorologists Wangenheim (1935; 1946) and Girs (1964; 1981), zonal Ws and meridional Wp circulation indices by Lityński (1969) and circulation indices by Niedźwiedź (1981; 2019): zonal circulation index - Wi, meridional circulation index - Si and cyclonicity index - Ci. A lot of works concerned air masses and atmospheric fronts. The research was undertaken on the influence of atmospheric circulation on selected climate elements. Most studies concerned the origin of heavy precipitation causing floods. © 2019 Przeglad Geofizyczny. All rights reserved.},

note = {6},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-85077643292,

title = {Warm winter and cold summer spells in Spitsbergen and their circulation conditions},

author = { A.M. Tomczyk and E.B. Łupikasza and S. Kendzierski},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85077643292&doi=10.24425%2fppr.2019.130902&partnerID=40&md5=938285d2dee252d7375f42f11f1c3969},

doi = {10.24425/ppr.2019.130902},

issn = {01380338},

year  = {2019},

date = {2019-01-01},

journal = {Polish Polar Research},

volume = {40},

number = {4},

pages = {339-359},

publisher = {Polish Academy of Sciences},

abstract = {The objective of the study was to determine multi-annual changes and variability of occurrence of cold spells in summer and warm spells in winter on Spitsbergen in the period 1976–2016, and circulation conditions of their occurrence. Cold days in summer were defined as days with mean daily air temperature lower than temperature corresponding to the 10th percentile from daily temperature, and warm days in winter as days with mean daily air temperature exceeding the 90th percentile from daily air temperature. The research showed a statistically significant increase in mean air temperature, the rate of which in winter was more than four times higher than in summer. The observed warming translated into a decrease in the number of cold days in summer (-2.5 days/10 years in Svalbard Lufthavn and -1.3 days/10 years in Ny-Ålesund) and an increase in the number of warm days in winter (2.7 days/10 years in Svalbard Lufthavn and 2.4 days/10 years in Ny-Ålesund), and warm and cold spells related to the frequency of such days. The rate of the changes was higher in Svalbard Lufthavn than in Ny-Ålesund. The occurrence of cold days and cold spells was particularly related to the advection of air masses from the north-western sector. The occurrence of warm days and warm spells was related to the advection of air masses from the south-west. Copyright © 2019. Tomczyk, Łupikasza and Kendzierski.},

note = {3},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-85028348816,

title = {Changes of flood risk on the northern foothills of the Tatra Mountains},

author = { Z.W. Kundzewicz and M. Stoffel and B. Wyżga and V. Ruiz-Villanueva and T. Niedźwiedź and R.J. Kaczka and J.A. Ballesteros-Cánovas and I. Pińskwar and E.B. Łupikasza and J. Zawiejska and P. Mikuś and A. Choryński and H. Hajdukiewicz and B. Spyt and K. Janecka},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85028348816&doi=10.1007%2fs11600-017-0075-0&partnerID=40&md5=547c7f6bae0285788c2936739d020ef2},

doi = {10.1007/s11600-017-0075-0},

issn = {18956572},

year  = {2017},

date = {2017-01-01},

journal = {Acta Geophysica},

volume = {65},

number = {4},

pages = {799-807},

publisher = {Springer International Publishing},

abstract = {The present paper reviews selected outcomes of the FLORIST project devoted to flood risk in the region of the northern foothills of the Tatra Mountains in Poland and summarizes novel results. The project encompassed theoretical, field, and modeling work. It was focused around observation-based hydroclimatology; projections for the future; dendrogeomorphology; as well as influence of transport of large wood on fluvial processes. The project improved understanding and interpreting changes in high-flow frequency and magnitude as well as changes in flood risk in the region, related to the presence of large wood in mountain streams. A unique database on past episodes of intense precipitation and flooding was created, harnessing multiple sources. The project showed that the analysis of tree rings and wood logs can offer useful information, complementing and considerably enriching the knowledge of river floods in the region of northern foothills of the Tatra Mountains. Retrospective and scenario-defined modeling of selected past fluvial events in the region was also performed. © 2017 The Author(s).},

note = {7},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-85054870232,

title = {Seasonal patterns and consistency of extreme precipitation trends in Europe, December 1950 to February 2008},

author = { E.B. Łupikasza},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85054870232&doi=10.3354%2fcr01467&partnerID=40&md5=271ee80010b8bb27ac1a0ea43730f110},

doi = {10.3354/cr01467},

issn = {0936577X},

year  = {2017},

date = {2017-01-01},

journal = {Climate Research},

volume = {72},

number = {3},

pages = {217-237},

publisher = {Inter-Research},

abstract = {Seasonal trends in extreme precipitation indices were investigated for 30 yr moving periods between December 1950 and February 2008. To update the 2008 to 2015 data, supplementary calculations were performed for >120 meteorological stations. A linear regression of the least squares method was used to calculate trend magnitudes. Trend significance was tested using the Mann-Kendall method. Changes in short-term trend frequency and temporal coherence were assessed. Extreme precipitation was defined as a daily amount exceeding the 95th percentile, calculated separately for each month and station using daily totals ≥1 mm. The spatial pattern of extreme precipitation trends varied by season. Significant extreme precipitation trends were rare, constituting approximately 25 to 30% of all analysed trends, and were seldom temporally coherent. Most of these significant trends were upward, except in summer, when a nearly equal frequency of positive and negative trends was found. Increases in the frequency and the total were a characteristic feature of extreme precipitation changes, particularly in winter. Seasonal variations in the spatial patterns of extreme precipitation trends may have resulted from seasonal changes in the prominence of the driving factors of precipitation. In spring, upward trends in Central and Western Europe were twice as frequent as the downward trends found primarily in Southern Europe. In summer, the percentages of significant downward trends in Western Europe and upward trends in Eastern Europe were similar. In autumn, a coherent decrease in extreme precipitation was clear in Central Europe. The spatial distribution of trend directions was the most consistent in winter. © The authors 2017.},

note = {17},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-85015382878,

title = {Cloud cover over spitsbergen and its relation to atmospheric circulation (1983-2015)},

author = { E.B. Łupikasza and O. Lipiński},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85015382878&doi=10.7163%2fGPol.0076&partnerID=40&md5=8a4ef34864994eb7fa2f5f5af2b1c8dc},

doi = {10.7163/GPol.0076},

issn = {00167282},

year  = {2017},

date = {2017-01-01},

journal = {Geographia Polonica},

volume = {90},

number = {1},

pages = {21-38},

publisher = {Polska Akademia Nauk},

abstract = {This paper discusses the cloud cover and its relation to atmospheric circulation over Spitsbergen during 1983-2015. It focuses on monthly and seasonal cloud covers and on the frequency of days with specific cloud cover (cloudless; clear; cloudy and completely overcast sky) and their relation to various circulation types. In the research period the cloud cover characteristics were differentiated over the island on both monthly and seasonal scales, and they strongly depended on the direction of air advection. The highest mean daily cloud cover was reported for circulation types with air advection from the south (S+SWc and S+SWa). The greatest variation in the cloud cover distribution was observed during the polar night (at Svalbard Lufthavn and Ny-Ålesund) or in the autumn (Hornsund). The long-term variability in the cloud cover significantly depends on the frequency of N+NEa type (negative correlation) and on S+SWc and W+NWc and Cc+Bc types (positive correlation), particularly in spring. © Ewa Łupikasza • Oskar Lipiński, Geographia Polonica & Institute of Geography and Spatial Organization Polish Academy of Sciences • Warsaw • 2017.},

note = {4},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-85054234011,

title = {Wind shear and the strength of severe convective phenomena-preliminary results from Poland in 2011-2015},

author = { W. Pilorz and I. Laskowski and E.B. Łupikasza and M. Taszarek},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85054234011&doi=10.3390%2fcli4040051&partnerID=40&md5=27fc67e89625e0994e6ebf0fb3d14acf},

doi = {10.3390/cli4040051},

issn = {22251154},

year  = {2016},

date = {2016-01-01},

journal = {Climate},

volume = {4},

number = {4},

publisher = {MDPI AG},

abstract = {Severe convective phenomena cause significant loss in the economy and, primarily, casualties. Therefore, it is essential to forecast such extreme events to avoid or minimize the negative consequences. Wind shear provides an updraft-downdraft separation in the convective cell, which extends the cell lifetime. Wind shears between a few different air layers have been examined in all damaging convective cases in Poland, taken from the European Severe Weather Database between 2011 and 2015, in order to find their values and patterns according to the intensity of this phenomenon. Each severe weather report was assigned wind shear values from the nearest sounding station, and subsequently the presented summary was made. It was found that wind shear values differ between the given phenomena and their intensity. This regularity is particularly visible in shears containing 0 km wind. The highest shears occur within wind reports. Lower values are associated with hail reports. An important difference between weak and F1+ tornadoes was found in most of the wind shears. Severe phenomena probability within 0-6 km and 0-1 km shears show different patterns according to the phenomena and their intensity. This finding has its application in severe weather forecasting. © 2016 by the authors.},

note = {7},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-84991619929,

title = {Recent warming on spitsbergen-influence of atmospheric circulation and sea ice cover},

author = { K. Isaksen and Ø. Nordli and E.J. Førland and E.B. Łupikasza and S. Eastwood and T. Niedźwiedź},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84991619929&doi=10.1002%2f2016JD025606&partnerID=40&md5=60bf4a9af6029a1c139e07facec1d467},

doi = {10.1002/2016JD025606},

issn = {01480227},

year  = {2016},

date = {2016-01-01},

journal = {Journal of Geophysical Research},

volume = {121},

number = {20},

pages = {11,913-11,931},

publisher = {Wiley-Blackwell},

abstract = {Spitsbergen has experienced some of the most severe temperature changes in the Arctic during the last three decades. This study relates the recent warming to variations in large-scale atmospheric circulation (AC), air mass characteristics, and sea ice concentration (SIC), both regionally around Spitsbergen and locally in three fjords. We find substantial warming for all AC patterns for all seasons, with greatest temperature increase in winter. A major part of the warming can be attributed to changes in air mass characteristics associated with situations of both cyclonic and anticyclonic air advection from north and east and situations with a nonadvectional anticyclonic ridge. In total, six specific AC types (out of 21), which occur on average 41% of days in a year, contribute approximately 80% of the recent warming. The relationship between the land-based surface air temperature (SAT) and local and regional SIC was highly significant, particularly for the most contributing AC types. The high correlation between SAT and SIC for air masses from east and north of Spitsbergen suggests that a major part of the atmospheric warming observed in Spitsbergen is driven by heat exchange from the larger open water area in the Barents Sea and region north of Spitsbergen. Finally, our results show that changes in frequencies of AC play a minor role to the total recent surface warming. Thus, the strong warming in Spitsbergen in the latest decades is not driven by increased frequencies of “warm” AC types but rather from sea ice decline, higher sea surface temperatures, and a general background warming. © 2016. The Authors.},

note = {99},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-84992036336,

title = {The role of atmospheric circulation in shaping total cloudiness over spitsbergen (1983-2013) [Rola cyrkulacji atmosfery w kształtowaniu wielkości zachmurzenia ogólnego na Spitsbergenie (1983-2013)]},

author = { O. Lipiński and E.B. Łupikasza},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84992036336&doi=10.7163%2fPrzG.2016.3.2&partnerID=40&md5=cfd2869f7c6c242e4371251f0a933dcf},

doi = {10.7163/PrzG.2016.3.2},

issn = {00332143},

year  = {2016},

date = {2016-01-01},

journal = {Przeglad Geograficzny},

volume = {88},

number = {3},

pages = {317-337},

publisher = {Polska Akademia Nauk},

abstract = {The main island of the Svalbard Archipelago, Spitsbergen, is located in the centre of the Atlantic sector of the Arctic and is exposed to an increased dynamic of change in weather conditions, the shaping of which is affected by specific synoptic situations. In the work described here, it was the impact of atmospheric circulation on cloudiness over Spitsbergen that was studied, by reference to (1983-2013) average daily values for cloudiness at the Ny-Ålesund, Svalbard Lufthavn and Hornsund Meteorological Stations. The influence of atmospheric circulation was examined on the basis of a simplifi ed Calendar of synoptic situations for Spitsbergen (Niedźwiedź; 2013), whose classification embraces 5 cyclonic, 5 anticyclonic and 1 undetermined type. The average daily values for cloudiness referred to provided the basis for further calculations of annual, monthly and seasonal values, with results then being presented in relation to the course over years and seasons, as conditioned by the amount of sunlight reaching Spitsbergen at different times of the year. The analysis thus took in the polar day, the polar night and two much shorter (spring and autumn) transition periods, which are of somewhat different lengths at the several different stations. Annual courses for the proportions of days capable of being regarded as characteristic were then described, while a final stage to the work concerned the relationship between cloudiness and the eleven aforementioned types of atmospheric circulation. Average values for sky cover with different circulation types were calculated, as were the conditional probabilities relating to the occurrence of the characteristic days. The results demonstrate that, notwithstanding environmental conditions, atmospheric circulation plays an important role in cloud formation over the whole island. However, despite the relatively short distances involved, the stations analysed were found to be characterised by signifi cant differences where the spatial distribution of values for levels of sky cover by cloud were concerned. The causal relationship between cloudiness and respective circulation types is not as important as the direction of advection of air masses. The highest mean daily cloudiness values were reported in circulation types entailing advection from the south, i.e. Sc+SWc and Sa+SWa (relating to both cyclonic and anticyclonic types). Lowest average levels of cloudiness co-occurred under the Na+NEa and Nc+NEc circulation types. The total number of characteristic days at particular stations is also quite varied. Ny-Ålesund reports the most cloudless days (N=0%) and clear days (N<20%) during the year. The same is true of the number of completely overcast days (N=100%). The largest number of cloudy days (N>80%) characterises Hornsund, the most southerly of the stations on Spitsbergen studied. At Svalbard Lufthavn, average cloudiness during the polar night is greatest when the air fl ow originates in the north. The greatest variation in the distribution of cloudiness is to be observed during the polar night (at Svalbard Lufthavn and Ny-Ålesund) or in the autumn transitional period (Hornsund). © 2016, Polska Akademia Nauk. All rights reserved.},

note = {5},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-84893845969,

title = {Variability of high rainfalls and related synoptic situations causing heavy floods at the northern foothills of the Tatra Mountains},

author = { T. Niedźwiedź and E.B. Łupikasza and I. Pińskwar and Z.W. Kundzewicz and M. Stoffel and Ł. Małarzewski},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84893845969&doi=10.1007%2fs00704-014-1108-0&partnerID=40&md5=a504da9e4fc2dbe87fce1c526b205116},

doi = {10.1007/s00704-014-1108-0},

issn = {0177798X},

year  = {2015},

date = {2015-01-01},

journal = {Theoretical and Applied Climatology},

volume = {119},

number = {1-2},

pages = {273-284},

publisher = {Springer-Verlag Wien},

abstract = {This contribution provides the basics of the climatology of the Polish Tatra Mountains in a nutshell, with particular reference to intense precipitation and its relation to atmospheric circulation. Variability of various precipitation characteristics, including selected indices of intense precipitation in Zakopane and at Kasprowy Wierch, is illustrated in this paper. None of the trends in these characteristics and indices calculated for the entire time interval exhibit a statistical significance, but short-time fluctuations are evident. The occurrence of intense precipitation in the Tatra Mountains is strongly related to three circulation types. These situations (Nc; NEc; Bc) are associated with cyclones following track Vb after van Bebber. In addition to changing frequencies of circulation, this study also reveals an increase in the frequency of the circulation types associated with extreme precipitation. © 2014, The Author(s).},

note = {59},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-84907845547,

title = {Regional differentiation in probability of ice days occurrence in Poland},

author = { E.B. Łupikasza and T. Niedźwiedź and Ł. Małarzewski},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84907845547&doi=10.2478%2fquageo-2014-0032&partnerID=40&md5=4f42e4021a08c29b143b9649b6fdea14},

doi = {10.2478/quageo-2014-0032},

issn = {0137477X},

year  = {2014},

date = {2014-01-01},

journal = {Quaestiones Geographicae},

volume = {33},

number = {3},

pages = {89-99},

publisher = {Adam Mickiewicz University Press},

abstract = {This paper aims at recognizing spatial differentiation in probability of ice days occurrence with reference to atmospheric circulation, using regional classification of circulation types for Poland. Daily maximum air temperatures measured at nine meteorological stations were used to recognize the ice days occurrence in the period from January 1951 to March 2014. The relations between the ice days occurrence and atmospheric circulation were analysed using catalogues of circulation types compiled for nine grid boxes within Poland. Linkage between the frequency of ice days and atmospheric circulation was recognized in the period of January 2001 - March 2014. A decreasing tendency in the frequency of the occurrence of winter ice days was found. The occurrence of ice days in Poland is clearly related to atmospheric circulation. In the entire area of Poland their occurrence is favoured by eastern and south-eastern advection of air during anticyclonic conditions (types Ea nad SEa). Regional variability is also noticeable. © Faculty of Geographical and Geological Sciences, Adam Mickiewicz University 2014.},

note = {3},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-84897574087,

title = {Floods at the northern foothills of the Tatra Mountains - A Polish-Swiss research project},

author = { Z.W. Kundzewicz and M. Stoffel and R.J. Kaczka and B. Wyżga and T. Niedźwiedź and I. Pińskwar and V. Ruiz-Villanueva and E.B. Łupikasza and B. Czajka and J.A. Ballesteros-Cánovas and Ł. Małarzewski and A. Choryński and K. Janecka and P. Mikuś},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84897574087&doi=10.2478%2fs11600-013-0192-3&partnerID=40&md5=aa20aa74877ee8cbd69a98765bb40dc7},

doi = {10.2478/s11600-013-0192-3},

issn = {18956572},

year  = {2014},

date = {2014-01-01},

journal = {Acta Geophysica},

volume = {62},

number = {3},

pages = {620-641},

publisher = {Versita},

abstract = {The present paper introduces the topical area of the Polish-Swiss research project FLORIST (Flood risk on the northern foothills of the Tatra Mountains), informs on its objectives, and reports on initial results. The Tatra Mountains are the area of the highest precipitation in Poland and largely contribute to flood generation. The project is focused around four competence clusters: observation-based climatology, model-based climate change projections and impact assessment, dendrogeomorphology, and impact of large wood debris on fluvial processes. The knowledge generated in the FLORIST project is likely to have impact on understanding and interpretation of flood risk on the northern foothills of the Tatra Mountains, in the past, present, and future. It can help solving important practical problems related to flood risk reduction strategies and flood preparedness. © 2014 Versita Warsaw and Springer-Verlag Wien.},

note = {46},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-84864285925,

title = {Long-term variability of occurrence of precipitation forms in winter in Kraków, Poland},

author = { R. Twardosz and E.B. Łupikasza and T. Niedźwiedź and A. Walanus},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84864285925&doi=10.1007%2fs10584-011-0352-x&partnerID=40&md5=c1a73793307993ce56646b91be4aab50},

doi = {10.1007/s10584-011-0352-x},

issn = {01650009},

year  = {2012},

date = {2012-01-01},

journal = {Climatic Change},

volume = {113},

number = {3-4},

pages = {623-638},

abstract = {The paper discusses long-term change in snowfall, rainfall and mixed precipitation viewed in conjunction with air temperature and North Atlantic Oscillation (NAO) in winter (December-February). In the study of contemporary climate change and its effect on the hydrological cycle it is useful to focus on winter precipitation forms. A 146-year secular observation series from Kraków, spanning the period 1863-2008, was used to extract data on the number of days with precipitation and on precipitation amount broken down by form. Statistically significant trends were found in total and mixed precipitation, but not in snowfall and rainfall. The climate warming effect has contributed to a material decrease in the snowfall to total winter precipitation ratio during the second half of the 20th c. The highest impact of air temperature was found in the wintertime variation in number of days with snowfall while the NAO had a significant influence on the frequency and amount of both rainfall and snowfall. © 2011 The Author(s).},

note = {12},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-81155130044,

title = {Regional and seasonal variability of extreme precipitation trends in southern Poland and central-eastern Germany 1951-2006},

author = { E.B. Łupikasza and S. Hänsel and J. Matschullat},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-81155130044&doi=10.1002%2fjoc.2229&partnerID=40&md5=18558286a810e6098e73c1dcff773e44},

doi = {10.1002/joc.2229},

issn = {08998418},

year  = {2011},

date = {2011-01-01},

journal = {International Journal of Climatology},

volume = {31},

number = {15},

pages = {2249-2271},

abstract = {Spatial and temporal trend variability in extreme precipitation indices was studied for the meteorological seasons from 1951 to 2006. Eight indices were used, describing their frequency (90pNoD; 95pNoD), totals (1dayT; 5dayT; 90pT; 95pT) and intensity (90pInt; 95pInt). The following key challenges were addressed: (1) temporal variability in the relative number of stations with significant 30-year trends, (2) temporal stability and (3) average magnitude of the calculated 30-year trends. Temporal changes in the spatial extent of statistically significant extreme precipitation trends proceeded differently in each season. The trend direction, indicated by trend stability analysis, was consistent with that of averaged 30-year trend magnitudes at most stations. A distinct spatial differentiation emerged in the prevailing trend directions between the eastern and the western part of the study area. In all seasons, increasing trends in extreme precipitation dominated in central-eastern Germany, whereas opposite trends prevailed in southern Poland. This pattern was particularly prominent in winter. Similarities in the temporal variability of the percentage of significant trends between the eastern and the western sub-regions emerged in autumn only. Summer was characterized by the most pronounced temporal changes in the percentage of significant negative trends. Summer also showed the most stable extreme precipitation trends of all seasons and a higher trend magnitude than the transitional seasons. Spatial patterns of trend directions in spring, showing the most complex pattern of all seasons, vary depending on the index, particularly with respect to trend stability. © 2010 Royal Meteorological Society.},

note = {79},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-79955063408,

title = {The influence of atmospheric circulation on the type of precipitation (Kraków, southern Poland)},

author = { R. Twardosz and T. Niedźwiedź and E.B. Łupikasza},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-79955063408&doi=10.1007%2fs00704-010-0340-5&partnerID=40&md5=76e98ee6b0ef9ae62ddab656d44c9cea},

doi = {10.1007/s00704-010-0340-5},

issn = {0177798X},

year  = {2011},

date = {2011-01-01},

journal = {Theoretical and Applied Climatology},

volume = {104},

number = {1-2},

pages = {233-250},

publisher = {Springer-Verlag Wien},

abstract = {The paper discusses the impact of atmospheric circulation on the occurrence of various types of precipitation. A 146-year-long precipitation record from Kraków spanning the period 1863-2008 was used alongside a calendar prepared by Niedźwiedź (1981; 2009) describing circulation types covering the period 1873-2008 and air masses and atmospheric fronts covering the period 1951-2008 in southern Poland. The influence of atmospheric circulation on precipitation was measured using the frequency, conditional probability and average daily totals of precipitation. Circulation types, air masses and atmospheric fronts exerted influences on precipitation as a result of the seasonal variations of the thermal and moisture properties of air masses. The impact is best expressed by circulation types as these combine the aspect of cyclonicity/anticyclonicity with that of the direction of air advection, the two elements which determine the physical properties of the air. On average, liquid precipitation prevailed in all circulation types, except the Ea type in which snowfall dominated over liquid precipitation. Depending on the season, one of the three types of circulation, Wa, Wc and Bc, were shown to coincide with the greatest amount of liquid and thunderstorm precipitation. There was no single dominant circulation type for mixed precipitation or snowfall. In summer, the circulation types Nc, NEc, Cc and Bc were the most favourable to liquid and thunderstorm precipitation in terms of both probability and totals. In winter, snowfall was the most favoured by the Ec type. Frontal precipitation was twice as likely to occur as air mass precipitation, with the exception of snowfall which was predominantly an air mass type of precipitation in terms of probability, but its greatest totals were recorded on atmospheric fronts. © 2010 The Author(s).},

note = {28},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-77953153959,

title = {Spatial and temporal variability of extreme precipitation in poland in the period 1951-2006},

author = { E.B. Łupikasza},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-77953153959&doi=10.1002%2fjoc.1950&partnerID=40&md5=6d8aafa0742183dbcec62acdd5f7f368},

doi = {10.1002/joc.1950},

issn = {08998418},

year  = {2010},

date = {2010-01-01},

journal = {International Journal of Climatology},

volume = {30},

number = {7},

pages = {991-1007},

abstract = {The study investigated spatial and temporal variability of extreme precipitation trend magnitudes and their directions. Daily precipitation from 48 synoptic stations in Poland for the period 1951-2006 were used. Five indices of precipitation extremes were chosen: the highest 5-day precipitation total, precipitation total from events ≥90th and 95th percentiles as well as number of days with precipitation ≥90th and 95th percentiles of daily precipitation amount. Trends in extreme precipitation indicators were analysed over semi-annual periods as well as over the standard climatological seasons. Trends were calculated for each of the 30-year moving periods within 1951-2006 using a simple linear regression method. Their significance was tested with the Mann-Kendall method. Decreasing trends in extreme precipitation indices dominated in both the warm and cool halves of the year and in the seasons. The greatest change was recorded in the least extreme precipitation indices. Summer was the season with the greatest number of statistically significant trends, mostly decreasing ones. Upward trends, having the greatest spatial extend in autumn, dominated the initial 30-year periods of the study period whereas the decreasing trends were common in the 30-years from 1956. In summer and winter, decreasing trends reached the greatest degrees of stability in southern Poland. In spring and autumn, a stable fall of extreme precipitation indices was mainly recorded in the south-western part of the country. Stable increasing trends were recorded sporadically. However, in spring trends towards an increase were more frequent than in other seasons. The strongest decreasing trends were observed in summer and winter, mainly in the south, while in autumn they also occurred in the west. © 2009 Royal Meteorological Society.},

note = {97},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-77954954198,

title = {Relationships between occurrence of high precipitation and atmospheric circulation in Poland using different classifications of circulation types},

author = { E.B. Łupikasza},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-77954954198&doi=10.1016%2fj.pce.2009.11.012&partnerID=40&md5=9f65d68198f86f2765dffc09650bebe0},

doi = {10.1016/j.pce.2009.11.012},

issn = {14747065},

year  = {2010},

date = {2010-01-01},

journal = {Physics and Chemistry of the Earth},

volume = {35},

number = {9-12},

pages = {448-455},

abstract = {The main objective of this study is to analyse the relationship between atmospheric circulation and high precipitation in Poland, using selected classifications of circulation types. Daily precipitation totals from 48 synoptic stations and three classifications of circulation types (Litynski; 1969; Niedzwiedz; 1981; 2008; Ustrnul; 1997) were used. These classifications were described and compared. The relationships between high precipitation and atmospheric circulation were analysed by (i) determining those circulation types that favour the occurrence of high precipitation, (ii) analysing the spatial differentiation of the probability of high precipitation events for chosen cyclonic circulation types and (iii) the usefulness of the classifications to analyse relations between high precipitation in Poland and atmospheric circulation was assessed.Any study of relations between atmospheric circulation and climate elements demands a preceding detailed assessment of the usefulness of a given classification for a defined problem. The results for relations between high precipitation occurrence and circulation depend on the rules applied to classify circulation types. Ustrnul's classification seems to be best suited to study the relationship between heavy precipitation and circulation in the southern part of Poland. This result is based on two methods, the range of probabilities for high precipitation in each circulation type of a given classification (Prdiff) and the Brier skill score (BSS). The Niedzwiedz classification mainly produces very good results in central southern Poland where its probability range is clearly wider than elsewhere. Both methods seem to be less useful to study the relationships between high precipitation and circulation in northern Poland. Litynski's classification delivers a greater role of the cyclonic types in forming high precipitation, but no definite prevailing type can be identified at many of the stations. When analysing relations, regional classification of circulation should be applied rather than macro-scales ones. © 2009 Elsevier Ltd.},

note = {27},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-67349226876,

title = {Long-term precipitation variability on thunderstorm days in Poland (1951-2000)},

author = { Z. Bielec-Bąkowska and E.B. Łupikasza},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-67349226876&doi=10.1016%2fj.atmosres.2008.09.018&partnerID=40&md5=82be7a52360d98a21d1ade255569ed9f},

doi = {10.1016/j.atmosres.2008.09.018},

issn = {01698095},

year  = {2009},

date = {2009-01-01},

journal = {Atmospheric Research},

volume = {93},

number = {1-3},

pages = {506-515},

abstract = {The paper discusses the frequency of precipitation, broken down into amount categories, on thunderstorm days in Poland during the period 1951-2000. The authors looked at the number of thunderstorm days with precipitation versus the total thunderstorm days. Frequencies of certain precipitation totals on thunderstorm days were determined for various Polish regions, as well as long-term and annual precipitation variabilities. Daily precipitation and thunderstorm observation records from 47 Polish weather stations were used in the study. Precipitation on thunderstorm days was broken down into the following categories: dry day or trace precipitation, 0.1-10.0 mm, 10.1-20.0 mm, 20.1-30.0 mm, and more than 30.0 mm. These categories were studied for variability in five thunderstorm regions in Poland. The study revealed at that precipitation occurred on most of the thunderstorm days in the second half of the 20th century in Poland (on average 85% of cases). On 63% of thunderstorm days there was between 0.1 and 10.0 mm of rain. Cases of more than 30.0 mm of precipitation were very rare (2.7%) and were recorded mostly in mountainous areas. Annual frequencies of the various precipitation categories were similar across all of the regions. There was more variability in the long-term view, but in most cases no clear trend could be established. Slight decrease in number of thunderstorm days without precipitation (statistically significant in regions II and III) and an increase in days with the lowest precipitation, 0.1-10.0 mm (statistically significant in region V) was stated. © 2008 Elsevier B.V. All rights reserved.},

note = {12},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-72249110125,

title = {Variability of selected extreme meteorological events in Poland},

author = { E.B. Łupikasza and Z. Bielec-Bąkowska and M. Falarz},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-72249110125&doi=10.7163%2fGPol.2009.1.1&partnerID=40&md5=4d5002dc00e6498df1959acec3ff407e},

doi = {10.7163/GPol.2009.1.1},

issn = {00167282},

year  = {2009},

date = {2009-01-01},

journal = {Geographia Polonica},

volume = {82},

number = {1},

pages = {5-20},

publisher = {Polska Akademia Nauk},

abstract = {The principal aim of this paper is to analyze the trends of the multi-annual course of the selected characteristics of extreme precipitation, snow cover and atmospheric thunderstorms in the second half of the twentieth century in Poland. The results of these investigations show that in Poland it is only possible to determine a weak decreasing trend of extreme precipitation events in the S and especially in the SW part of the country. In northern Poland, opposite, although similarly weak, trends have also been observed. It is assumed that the most essential features of long-term changeability of extreme precipitation include a higher than average number of days with extremely high precipitation during the 1960s and 1970s, a distinctly lower frequency of such days during the 1950s, 1980s and in the first half of the 1990s. In Poland it is possible to distinguish four broad homogenous areas in terms of the long-term changes in the occurrence of extreme precipitation events. There is considerable regional differentiation when it comes to the occurrence of thunderstorms in Poland, and their long-term changeability does not show any clear trends. Only three stations have determined a weak increase in the number of thunderstorms during the last 120 years. In some stations, an increase in the number of days with thunderstorms during the winter seasons was also observed. There were no significant trends in extreme snow cover in Poland. The periods that contained large and small areas of extreme snow cover thickness occurred alternately. Since the winter season 1987/88, the area of extremely thin snow cover has remained at a relatively high level.},

note = {1},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-38149091505,

title = {Typology of the precipitation regimes in Europe [Typologia reżimów opadowych w Europie]},

author = { E.B. Łupikasza},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-38149091505&partnerID=40&md5=4069ea6e1253e3386c1f2029214fe610},

issn = {01371983},

year  = {2006},

date = {2006-01-01},

journal = {Annales Universitatis Mariae Curie-Sklodowska. Sectio B},

volume = {61},

pages = {267-276},

abstract = {The goal of this study was a typology of the precipitation regimes in Europe. The base dataset contains average values (1961-1990) of monthly precipitation totals from 666 meteorological stations. Cluster analysis of k-means method was used to determine precipitation types. The necessity of taking a subjective decision concerning the number of distinguished clusters is the main disadvantage of this method. Finally, it occurred that 12 types of annual precipitation course could be distinguished in Europe: two marine types, three continental types, two transitional types, two Mediterranean types and three mountain types. The graphs of averaged annual course of precipitation as well as the charts of their occurrence were shown. Ascribing the names to particular precipitation types one was guided by the shapes of graphs of the annual course of precipitation and their location.},

note = {1},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-5544301563,

title = {Variability of the precipitation irregularity index in Europe in the XXth century and its connection with the North Atlantic Oscillation (NAO) [Zmienność wskaznika nierónomierności opadów w Europie w XX wieku oraz jego zwia̧zki ze zmienności ̧wskaźnika NAO]},

author = { E.B. Łupikasza},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-5544301563&partnerID=40&md5=26bdb4e6d6f20cb25636d36d419874f7},

issn = {02084589},

year  = {2001},

date = {2001-01-01},

journal = {Prace i Studia Geograficzne},

volume = {29},

pages = {243-252},

publisher = {Wydawnictwa Uniwersytetu Warzawskiego},

abstract = {In this article the multiyear variability of the annual course of precipitation in Europe in the XX century was submitted to analysis. The annual course of precipitation was expressed as the precipitation irregularity index W (Wilgat, 1948). The differences of the W index between its values counted for normal periods 1931-1960 and 1961-1990 (on the base of 388 meteorological stations), the linear trends of W index in the periods 1900-1990, 1931-1990, 1961-1990 (on the base of 188 meteorological stations) and the course (1900-2000) of W index at selected 31 meteorological stations were subjected to assessment. Moreover the course of the W index was compared with the course of North Atlantic Oscillation Index. It was stated that the differences of the precipitation irregularity index values varied from - 11,5% in Russia to 19,6% in Romania. The most significant increase of the W index values was noticed on the West coast of Scandinavian Peninsula, in the area localised between the Black Sea and the Caspian Sea. The decrease of the W index values were evident in the North-Eastern Europe, East part of France, Sicily, The Balears and in the central part of Italy. The statistically significant increasing trend of the W index was observed in the North, East and North-Eastern part of Europe and at the individual meteorological stations in Poland and Germany in the periods 1900-1990, 1931-1990 and the decreasing one on the British Isles and in the North-Eastern part of Europe mainly in the period 1961-1990. At the most of the meteorological stations localised in the Central, East and North-Eastern part of Europe and in Jan Mayen and Stykkisholmur the increase of pluvial oceanity were observed in the 90th. The relationship between The W and NAO indices were different depending on seasonal values of the circulation index (winter, spring, summer, autumn). Finally it was affirmed that the annual course of precipitation was subordinate to great variability but didn't undergo durable changes. In any areas of Europe it wasn't stated the changes of the precipitation regime.},

note = {2},

keywords = {},

pubstate = {published},

tppubtype = {article}

}