Precipitation structures are easy to detect, however, the mesoscale atmospheric processes which t... more Precipitation structures are easy to detect, however, the mesoscale atmospheric processes which they reflect are challenging to understand in Polar Regions and hard to model numerically. Currently, the spatial distribution of precipitation can be tracked at the resolution of minutes and seconds. For this purpose, the researchers at the Ukrainian Antarctic Akademik Vernadsky station employ several near-ground measurement systems and the Micro Rain Radar for remote vertical measurements. Measurements show stochastic precipitation variability caused by turbulence, precipitation bands related to the atmospheric processes of its formation, phase transition (melting) zones, and wind shears. The time scale of bands in the stratiform precipitation typically varied in the range of 5—15 minutes and corresponded to the 2—15 km spatial scale of atmospheric circulations according to the modeled parameters of the atmosphere. The Polar Weather Research and Forecast (Polar WRF) model was used to re...
In the late 20 th century, warming on the Antarctic Peninsula was most pronounced compared to oth... more In the late 20 th century, warming on the Antarctic Peninsula was most pronounced compared to other parts of Antarctica. However, air temperature showed a significant variability, which has become especially evident in recent decades. Thus, the investigation of air temperature trends on the Antarctic Peninsula is important. This study examines the extreme air temperature at the Ukrainian Antarctic Akademik Vernadsky station, located on Galindez Island, Argentine Islands Archipelago, near the Antarctic Peninsula. For 1951 to 2020, based on the daily air temperature data, the temporal trends of extreme air temperature were analyzed, using 11 extreme temperature indices. Based on linear trend analysis and the Mann-Kendall trend test, the TXn, TNn, TN90p, and TN90p indices showed an upward trend, whereas theFD0, ID0, TN10p, TX10p, and DTR indices showed a downward trend. Among them, annually, FD0, ID0, and TN10p significantly decreased by-0.427 days,-0.452 days, and-0.465%, respectively, whereas TXn and TNn increased by 0.164℃ and 0.201℃, respectively. The indices TXx and TNn showed no statistically significant trends. The average annual difference between TX and TN (index DTR) showed a nonsignificant decreasing trend at-0.029℃ year-1. Thus, for the period of 1951-2020, the Ukrainian Antarctic Akademik Vernadsky station was subjected to warming.
Visnik ukrains'kogo tovaristva genetikiv i selekcioneriv, 2021
Aim. The aim was to estimate inflow of nitrogen and phosphorus to the terrestrial substrate, fres... more Aim. The aim was to estimate inflow of nitrogen and phosphorus to the terrestrial substrate, freshwater pools, as well as in the ice core and subglacial waters, from the sea-bird colonies, and locations of non-colonial flying birds, or individual colonial birds activity. Methods. The samples of substrates, fresh waters, ice cores and samples from the subglacial waters collected during the 25th (2019/20) and 26th (2020/21) Ukrainian Antarctic expeditions in the area of the Argentine Islands – Kyiv Peninsula were analyzed by selected indicators of ornithogenic impact – concentration of bioaviable forms of nitrogen and phosphorus. Results. The concentration for nitrogen and phosphorus are shown to be ornitogenic in samples from all explored locations. High concentrations of ornithogenic compounds were detected not only inflowing from birds colonies, in particular penguins, but also in samples without their influence. Conclusions. The obtained data confirm the high level of influence of...
Objective. This paper deals with an estimation of the climate change at the Antarctic Peninsula r... more Objective. This paper deals with an estimation of the climate change at the Antarctic Peninsula region. During last decades, the most significant warming is observed in Polar regions, particularly in the Antarctic Peninsula region, where the Ukrainian Antarctic Akademik Vernadsky station is located. Therefore, the providing of the complex estimation of climate change trend is an important task for the region. These changes are taking place nowadays and will happen in the future. So, the main objective of the study is to estimate changes of climate characteristics in the Antarctic Peninsula region in the 21 st century, based on calculation of the relevant climate indices. The projections of the temperature and precipitation characteristics in the Antarctic Peninsula region and Akademik Vernadsky station area for RCP4.5 and RCP8.5 scenarios are the objects of the research. Methods of the research are numerical simulation and statistical analysis of the regional climate model data for the Antarctic Peninsula region from the International Project Polar-CORDEX. Spatial distribution of this data is 0.44° and three periods are under consideration: historical climatic period (1986-2005) and two future periods 2041-2060 and 2081-2100. The R-code language and the modified computing code developed by Climate4R Hub project in Jupiter Notebook environment were used for climate data analysis in this research. Six parameters were chosen to estimate climate change in the Antarctic Peninsula region: number of frost days with minimal air temperature (Т) less 0 °C, number of ice days with maximal Т less 0 °C, annual total precipitation, mean precipitation rate, maximum yearly duration of periods without precipitation, maximum yearly duration of periods with precipitation more than 1 mm per day. Results as an analysis of the cold temperature indices are presented in the Part I of the paper, while an analysis of the wet/dry indices will be presented in the Part II of the paper. Conclusions. Over the Antarctic Peninsula region, both scenarios project an average decrease in the cold season period. This process will be more pronounced for the RCP 8.5 scenario, when even to the middle of the century the period with negative temperatures is rapidly decreasing over the Larsen Ice Sheet area, which may cause its total or partial collapse. Over Akademik Vernadsky station area, the climate indices changes will almost triple as high as the averaged values over the Antarctic Peninsula for the two scenarios, indicating a greater vulnerability to the climate change in the area.
The aim of the study is to analyze seasonal and interannual changes in sea level on the western c... more The aim of the study is to analyze seasonal and interannual changes in sea level on the western coast of the Antarctic Peninsula. Objects of study are seasonal and interannual variability of sea level, air temperature, pressure at sea level, precipitation in the period 1960-2018 at the Faraday/Akademik Vernadsky station, which was considered as representative site for the Antarctic Peninsula. Statistical methods of study were used, including estimates of linear trends of time series using the nonparametric Sen's estimator of slope. The Mann-Kendall test was used to assess the significance of the slope of the trend. Time variability analysis was performed using wavelet analysis. Using the MATrix LABoratory (MATLAB) software package, squared of wavelet coefficients were calculated depending on the scale and shift or scalograms that characterize the local energy spectrum, and scalegrams calculated by averaging the scalograms by time shifts. The Morlet wavelet transformations were used. The results of the calculations showed that the trend of sea level at the Faraday/ Akademik Vernadsky station in the period 1960-2018, according to observations and correction on glacial isostatic adjustment of the crust is in the range from 3.05 to 3.45 mm/year, which is significantly higher than the global trend of 2.1 mm/year. Sea level scalograms allow estimating time-averaged periods and amplitudes of the coefficients for each season. In the austral winter and spring characteristic periods were 4-6 years, whereas the summer and autumn periods are characterized by 6-8 years, as well as by the highest amplitudes of the coefficients. All seasons are characterized by the appearance of a weakly pronounced period of about 4 years. The presence of peaks in the scalegrams at 6-8 and 3-4 years confirms the relationship of atmospheric and oceanic processes in West Antarctica to the natural variations of the ocean-atmosphere system, such as the Southern Annular Mode and El Niño-Southern Oscillation, which varies with typical 3-4 and 6-8 year periods. It was concluded that, unlike air temperature, the sea level trend is relatively weakly depends on the season, with the exception of autumn, when sea level trend is three times smaller than the average value. At the same time, the air temperature trend is the largest in the austral winter and the lowest in the summer.
Investigating precipitation phase transitions is crucial for improving our understanding of preci... more Investigating precipitation phase transitions is crucial for improving our understanding of precipitation formation processes and impacts, particularly in Polar Regions. This study uses observational data and numerical modelling to investigate precipitation phase transitions in the western and northern Antarctic Peninsula (AP) during austral summer. The analysis is based on the ERA5 reanalysis product, dynamically downscaled using the Polar-WRF (Polar Weather Research and Forecasting) model, evaluated using regular meteorological observations and additional measurements made during the Year of Polar Prediction special observing period. We analyse three cases of extra-tropical cyclones bringing precipitation with phase transitions, observed at the Chilean station Professor Julio Escudero (King George Island, north of the AP) and the Ukrainian Antarctic Akademik Vernadsky station (western side of the AP) during the first week of December 2018. We use observed and modelled near-surface...
The Antarctic Peninsula region is of growing interest due to the regional climate change features... more The Antarctic Peninsula region is of growing interest due to the regional climate change features and related atmospheric circulation patterns. The regional mesoscale atmospheric model Polar Weather Research and Forecasting (WRF) v4.1.1 was used in this research to study a heavy precipitation event over the Ukrainian Antarctic Akademik Vernadsky station region (Antarctic Peninsula). The passage of the cyclone over the Antarctic Peninsula as a typical synoptic process as well as a case of the daily precipitation maximum amount of 2018 were chosen for investigation in this research. The estimation of the modelling quality and downscaling was done by comparing the obtained results with in-situ observation at the Akademik Vernadsky station and cross-domain tracking of average meteorological values and their deviation. The concept of the nested domains allowed to increase the horizontal resolution of the simulated atmosphere up to 1 km and to reproduce the wind regime of this region with...
<p>Measurements of precipitation has always had well known difficulties that caused... more <p>Measurements of precipitation has always had well known difficulties that caused inaccuracies. This is especially acute in Polar regions where prevailing solid precipitation is accomplished with strong winds. Alternatively some indirect methods of precipitation measurements still in development and numerous meteorological instruments have been created on their basis.</p><p>The Akademik Vernadsky station is located in the Antarctic Peninsula region with a large amount of precipitation and  the problem of its measuring has always been relevant here. Although the data of monthly precipitation have been found for Vernadsky (Faraday) station since 1964, the first standard Tretyakov precipitation gauge was set up there only in 1997. But in recent years, several new instruments for indirect precipitation measurement have been installed at the meteorological site. The consistency of their data are the subject for this study. </p><p>Direct comparison of all measurement devices as well as investigation of their estimations dependencies from other meteorological parameters are analysed and will be presented for the period 2019-2020. Originally various instruments showed huge differences in precipitation estimates. Deep analysis and correction of the measurement results according to weather conditions is obviously needed for bias reduction. But the local features of the extremely heterogeneous underlying surface of the region affect the vertical component of the wind, and can cause the natural small scale precipitation variability. </p><p>The advantages of indirect methods for precipitation measuring is a high sensitivity to registering even individual falling precipitation particles and, hence, the really high temporal resolution of the data. Therefore, it can be used for investigation of physical atmospheric processes. As an example, the case study of a cyclone with precipitation phase transition over Vernadsky station on December 5-6, 2020 is investigated and will be presented. A comparison of the measurement data of various devices (Tretyakov Precipitation Gauge, Snow Stick, Vaisala PWD22, Lufft WS100, METEK MRR-PRO) and the ERA-5 reanalysis was carried out. A vertical radar MRR-PRO is of special interest as a measuring instrument for polar regions because it can ignore surface snow transport and has proved reliability in the Antarctic environment recently. In Marine Antarctica this device can identify the height of precipitation melting and also show a number of other useful parameters. This complex of precipitation measurement instruments is planned to be used in the frames of the forthcoming YOPP-SH field campayne.</p>
<p>Synoptic-scale atmospheric circulation that transports moisture from low... more <p>Synoptic-scale atmospheric circulation that transports moisture from lower latitudes highly influences the Antarctic coastal climate, warming and moistening the lower troposphere and causing both precipitation and temperature increases. During recent decades, it has been shown that the highest warming rate over Antarctica is observed over the Antarctic Peninsula region. Heat and moisture transport from lower latitudes, particularly associated with atmospheric rivers (ARs), could play a crucial role in this warming. Among the most complex and understudied processes relate to microphysical properties of clouds and precipitation and understanding phase transitions during intense precipitation events associated with ARs and their representation in polar weather and climate models.</p><p>The goal of this research is  to investigate the temporal and spatial evolution of precipitation, including its intensity and phase transition and associated cloud properties during AR events over the Antarctic Peninsula in austral summer. We focus on two sites representing different regional and micro-climates around the Antarctic Peninsula - Escudero station, situated on King George Island at the northern tip of the peninsula, and Vernadsky station – located on Galindez Island at the western (upwind) side closer to the central part of the peninsula. Although both stations have typical maritime climate, the Vernadsky site is more affected by orographic enhancement of precipitation and cold air advection from the continent.</p><p>We use ground-based observations of meteorology, conducted during The Year of Polar Prediction Special Observing Period (YOPP-SOP) in summer 2018/2019 over the Antarctic Peninsula region and compare against ERA-5 and AMPS Polar WRF. After evaluating ERA-5 reanalysis , it is used for large-scale analysis of clouds and precipitation type. The timings of precipitation phase transitions in ERA-5 and Polar WRF are determined for the grid cells where the two stations are located. Sensitivity to microphysics parameterization in Polar WRF is tested with several double moment cloud microphysics parameterization schemes.</p><p>We analyze two cases with observed precipitation phase transitions, during the first week of December 2018. Higher precipitation amounts were observed over Vernadsky station during the first event and over Escudero during the second event. Total precipitation during the whole week is higher for Vernadsky station compared to Escudero station, related to the AR landfall position and strength, as well as the orographic enhancement at the upwind side of the Antarctic Peninsula ridge. This is confirmed by assessment of ERA-5 data. Comparison with the YOPP-SOP observations at Escudero shows that ERA-5 represents major precipitation type accurately and thus can be used for further study of precipitation microphysics. For Vernadsky station, ERA-5 showed a few cases of phase transition from snow to wet snow, associated with ARs events according to ERA-5 data; unfortunatly observations for comparison were lacking. Compared to ERA-5, Polar WRF shows a finer structure of precipitation fields disturbed by the mountains. We intend to test different parameterizations of cloud microphysics in Polar WRF with fine resolution against the complex of measurements at Vernadsky station in order to find the optimal configuration in the region to use during the upcoming winter YOPP in the Southern Hemisphere.</p>
The study presents analysis of microclimatic conditions on Galindez Island (western part of the A... more The study presents analysis of microclimatic conditions on Galindez Island (western part of the Antarctic Peninsula), in particular: seasonal variability and spatial heterogeneity. Based on land surface temperature (LST) data derived from loggers and MicroClimate Monitoring Station, we analyzed areas with active growth of local plants. Seasonal variations formed mainly under annual and semi-annual cycles, with no dependencies of amplitudes and phases form area location. LST highly correlates with air temperature and total incoming irradiance. It is emphasized that spatial orientation of relief microforms plays the most significant role for LST formation on micro-level. Using cluster analysis, it was found that temperature loggers which are located along shoreline and oriented to the north–north-east could be grouped by similar LST distribution.
<p>Synoptic-scale atmospheric circulation that transports moisture from low... more <p>Synoptic-scale atmospheric circulation that transports moisture from lower latitudes highly influences the Antarctic coastal climate, warming and moistening the lower troposphere and causing both precipitation and temperature increases. During recent decades, it has been shown that the highest warming rate over Antarctica is observed over the Antarctic Peninsula region. Heat and moisture transport from lower latitudes, particularly associated with atmospheric rivers (ARs), could play a crucial role in this warming. Among the most complex and understudied processes relate to microphysical properties of clouds and precipitation and understanding phase transitions during intense precipitation events associated with ARs and their representation in polar weather and climate models.</p><p>The goal of this research is  to investigate the temporal and spatial evolution of precipitation, including its intensity and phase transition and associated cloud properties during AR events over the Antarctic Peninsula in austral summer. We focus on two sites representing different regional and micro-climates around the Antarctic Peninsula - Escudero station, situated on King George Island at the northern tip of the peninsula, and Vernadsky station – located on Galindez Island at the western (upwind) side closer to the central part of the peninsula. Although both stations have typical maritime climate, the Vernadsky site is more affected by orographic enhancement of precipitation and cold air advection from the continent.</p><p>We use ground-based observations of meteorology, conducted during The Year of Polar Prediction Special Observing Period (YOPP-SOP) in summer 2018/2019 over the Antarctic Peninsula region and compare against ERA-5 and AMPS Polar WRF. After evaluating ERA-5 reanalysis , it is used for large-scale analysis of clouds and precipitation type. The timings of precipitation phase transitions in ERA-5 and Polar WRF are determined for the grid cells where the two stations are located. Sensitivity to microphysics parameterization in Polar WRF is tested with several double moment cloud microphysics parameterization schemes.</p><p>We analyze two cases with observed precipitation phase transitions, during the first week of December 2018. Higher precipitation amounts were observed over Vernadsky station during the first event and over Escudero during the second event. Total precipitation during the whole week is higher for Vernadsky station compared to Escudero station, related to the AR landfall position and strength, as well as the orographic enhancement at the upwind side of the Antarctic Peninsula ridge. This is confirmed by assessment of ERA-5 data. Comparison with the YOPP-SOP observations at Escudero shows that ERA-5 represents major precipitation type accurately and thus can be used for further study of precipitation microphysics. For Vernadsky station, ERA-5 showed a few cases of phase transition from snow to wet snow, associated with ARs events according to ERA-5 data; unfortunatly observations for comparison were lacking. Compared to ERA-5, Polar WRF shows a finer structure of precipitation fields disturbed by the mountains. We intend to test different parameterizations of cloud microphysics in Polar WRF with fine resolution against the complex of measurements at Vernadsky station in order to find the optimal configuration in the region to use during the upcoming winter YOPP in the Southern Hemisphere.</p>
Precipitation structures are easy to detect, however, the mesoscale atmospheric processes which t... more Precipitation structures are easy to detect, however, the mesoscale atmospheric processes which they reflect are challenging to understand in Polar Regions and hard to model numerically. Currently, the spatial distribution of precipitation can be tracked at the resolution of minutes and seconds. For this purpose, the researchers at the Ukrainian Antarctic Akademik Vernadsky station employ several near-ground measurement systems and the Micro Rain Radar for remote vertical measurements. Measurements show stochastic precipitation variability caused by turbulence, precipitation bands related to the atmospheric processes of its formation, phase transition (melting) zones, and wind shears. The time scale of bands in the stratiform precipitation typically varied in the range of 5—15 minutes and corresponded to the 2—15 km spatial scale of atmospheric circulations according to the modeled parameters of the atmosphere. The Polar Weather Research and Forecast (Polar WRF) model was used to re...
In the late 20 th century, warming on the Antarctic Peninsula was most pronounced compared to oth... more In the late 20 th century, warming on the Antarctic Peninsula was most pronounced compared to other parts of Antarctica. However, air temperature showed a significant variability, which has become especially evident in recent decades. Thus, the investigation of air temperature trends on the Antarctic Peninsula is important. This study examines the extreme air temperature at the Ukrainian Antarctic Akademik Vernadsky station, located on Galindez Island, Argentine Islands Archipelago, near the Antarctic Peninsula. For 1951 to 2020, based on the daily air temperature data, the temporal trends of extreme air temperature were analyzed, using 11 extreme temperature indices. Based on linear trend analysis and the Mann-Kendall trend test, the TXn, TNn, TN90p, and TN90p indices showed an upward trend, whereas theFD0, ID0, TN10p, TX10p, and DTR indices showed a downward trend. Among them, annually, FD0, ID0, and TN10p significantly decreased by-0.427 days,-0.452 days, and-0.465%, respectively, whereas TXn and TNn increased by 0.164℃ and 0.201℃, respectively. The indices TXx and TNn showed no statistically significant trends. The average annual difference between TX and TN (index DTR) showed a nonsignificant decreasing trend at-0.029℃ year-1. Thus, for the period of 1951-2020, the Ukrainian Antarctic Akademik Vernadsky station was subjected to warming.
Visnik ukrains'kogo tovaristva genetikiv i selekcioneriv, 2021
Aim. The aim was to estimate inflow of nitrogen and phosphorus to the terrestrial substrate, fres... more Aim. The aim was to estimate inflow of nitrogen and phosphorus to the terrestrial substrate, freshwater pools, as well as in the ice core and subglacial waters, from the sea-bird colonies, and locations of non-colonial flying birds, or individual colonial birds activity. Methods. The samples of substrates, fresh waters, ice cores and samples from the subglacial waters collected during the 25th (2019/20) and 26th (2020/21) Ukrainian Antarctic expeditions in the area of the Argentine Islands – Kyiv Peninsula were analyzed by selected indicators of ornithogenic impact – concentration of bioaviable forms of nitrogen and phosphorus. Results. The concentration for nitrogen and phosphorus are shown to be ornitogenic in samples from all explored locations. High concentrations of ornithogenic compounds were detected not only inflowing from birds colonies, in particular penguins, but also in samples without their influence. Conclusions. The obtained data confirm the high level of influence of...
Objective. This paper deals with an estimation of the climate change at the Antarctic Peninsula r... more Objective. This paper deals with an estimation of the climate change at the Antarctic Peninsula region. During last decades, the most significant warming is observed in Polar regions, particularly in the Antarctic Peninsula region, where the Ukrainian Antarctic Akademik Vernadsky station is located. Therefore, the providing of the complex estimation of climate change trend is an important task for the region. These changes are taking place nowadays and will happen in the future. So, the main objective of the study is to estimate changes of climate characteristics in the Antarctic Peninsula region in the 21 st century, based on calculation of the relevant climate indices. The projections of the temperature and precipitation characteristics in the Antarctic Peninsula region and Akademik Vernadsky station area for RCP4.5 and RCP8.5 scenarios are the objects of the research. Methods of the research are numerical simulation and statistical analysis of the regional climate model data for the Antarctic Peninsula region from the International Project Polar-CORDEX. Spatial distribution of this data is 0.44° and three periods are under consideration: historical climatic period (1986-2005) and two future periods 2041-2060 and 2081-2100. The R-code language and the modified computing code developed by Climate4R Hub project in Jupiter Notebook environment were used for climate data analysis in this research. Six parameters were chosen to estimate climate change in the Antarctic Peninsula region: number of frost days with minimal air temperature (Т) less 0 °C, number of ice days with maximal Т less 0 °C, annual total precipitation, mean precipitation rate, maximum yearly duration of periods without precipitation, maximum yearly duration of periods with precipitation more than 1 mm per day. Results as an analysis of the cold temperature indices are presented in the Part I of the paper, while an analysis of the wet/dry indices will be presented in the Part II of the paper. Conclusions. Over the Antarctic Peninsula region, both scenarios project an average decrease in the cold season period. This process will be more pronounced for the RCP 8.5 scenario, when even to the middle of the century the period with negative temperatures is rapidly decreasing over the Larsen Ice Sheet area, which may cause its total or partial collapse. Over Akademik Vernadsky station area, the climate indices changes will almost triple as high as the averaged values over the Antarctic Peninsula for the two scenarios, indicating a greater vulnerability to the climate change in the area.
The aim of the study is to analyze seasonal and interannual changes in sea level on the western c... more The aim of the study is to analyze seasonal and interannual changes in sea level on the western coast of the Antarctic Peninsula. Objects of study are seasonal and interannual variability of sea level, air temperature, pressure at sea level, precipitation in the period 1960-2018 at the Faraday/Akademik Vernadsky station, which was considered as representative site for the Antarctic Peninsula. Statistical methods of study were used, including estimates of linear trends of time series using the nonparametric Sen's estimator of slope. The Mann-Kendall test was used to assess the significance of the slope of the trend. Time variability analysis was performed using wavelet analysis. Using the MATrix LABoratory (MATLAB) software package, squared of wavelet coefficients were calculated depending on the scale and shift or scalograms that characterize the local energy spectrum, and scalegrams calculated by averaging the scalograms by time shifts. The Morlet wavelet transformations were used. The results of the calculations showed that the trend of sea level at the Faraday/ Akademik Vernadsky station in the period 1960-2018, according to observations and correction on glacial isostatic adjustment of the crust is in the range from 3.05 to 3.45 mm/year, which is significantly higher than the global trend of 2.1 mm/year. Sea level scalograms allow estimating time-averaged periods and amplitudes of the coefficients for each season. In the austral winter and spring characteristic periods were 4-6 years, whereas the summer and autumn periods are characterized by 6-8 years, as well as by the highest amplitudes of the coefficients. All seasons are characterized by the appearance of a weakly pronounced period of about 4 years. The presence of peaks in the scalegrams at 6-8 and 3-4 years confirms the relationship of atmospheric and oceanic processes in West Antarctica to the natural variations of the ocean-atmosphere system, such as the Southern Annular Mode and El Niño-Southern Oscillation, which varies with typical 3-4 and 6-8 year periods. It was concluded that, unlike air temperature, the sea level trend is relatively weakly depends on the season, with the exception of autumn, when sea level trend is three times smaller than the average value. At the same time, the air temperature trend is the largest in the austral winter and the lowest in the summer.
Investigating precipitation phase transitions is crucial for improving our understanding of preci... more Investigating precipitation phase transitions is crucial for improving our understanding of precipitation formation processes and impacts, particularly in Polar Regions. This study uses observational data and numerical modelling to investigate precipitation phase transitions in the western and northern Antarctic Peninsula (AP) during austral summer. The analysis is based on the ERA5 reanalysis product, dynamically downscaled using the Polar-WRF (Polar Weather Research and Forecasting) model, evaluated using regular meteorological observations and additional measurements made during the Year of Polar Prediction special observing period. We analyse three cases of extra-tropical cyclones bringing precipitation with phase transitions, observed at the Chilean station Professor Julio Escudero (King George Island, north of the AP) and the Ukrainian Antarctic Akademik Vernadsky station (western side of the AP) during the first week of December 2018. We use observed and modelled near-surface...
The Antarctic Peninsula region is of growing interest due to the regional climate change features... more The Antarctic Peninsula region is of growing interest due to the regional climate change features and related atmospheric circulation patterns. The regional mesoscale atmospheric model Polar Weather Research and Forecasting (WRF) v4.1.1 was used in this research to study a heavy precipitation event over the Ukrainian Antarctic Akademik Vernadsky station region (Antarctic Peninsula). The passage of the cyclone over the Antarctic Peninsula as a typical synoptic process as well as a case of the daily precipitation maximum amount of 2018 were chosen for investigation in this research. The estimation of the modelling quality and downscaling was done by comparing the obtained results with in-situ observation at the Akademik Vernadsky station and cross-domain tracking of average meteorological values and their deviation. The concept of the nested domains allowed to increase the horizontal resolution of the simulated atmosphere up to 1 km and to reproduce the wind regime of this region with...
<p>Measurements of precipitation has always had well known difficulties that caused... more <p>Measurements of precipitation has always had well known difficulties that caused inaccuracies. This is especially acute in Polar regions where prevailing solid precipitation is accomplished with strong winds. Alternatively some indirect methods of precipitation measurements still in development and numerous meteorological instruments have been created on their basis.</p><p>The Akademik Vernadsky station is located in the Antarctic Peninsula region with a large amount of precipitation and  the problem of its measuring has always been relevant here. Although the data of monthly precipitation have been found for Vernadsky (Faraday) station since 1964, the first standard Tretyakov precipitation gauge was set up there only in 1997. But in recent years, several new instruments for indirect precipitation measurement have been installed at the meteorological site. The consistency of their data are the subject for this study. </p><p>Direct comparison of all measurement devices as well as investigation of their estimations dependencies from other meteorological parameters are analysed and will be presented for the period 2019-2020. Originally various instruments showed huge differences in precipitation estimates. Deep analysis and correction of the measurement results according to weather conditions is obviously needed for bias reduction. But the local features of the extremely heterogeneous underlying surface of the region affect the vertical component of the wind, and can cause the natural small scale precipitation variability. </p><p>The advantages of indirect methods for precipitation measuring is a high sensitivity to registering even individual falling precipitation particles and, hence, the really high temporal resolution of the data. Therefore, it can be used for investigation of physical atmospheric processes. As an example, the case study of a cyclone with precipitation phase transition over Vernadsky station on December 5-6, 2020 is investigated and will be presented. A comparison of the measurement data of various devices (Tretyakov Precipitation Gauge, Snow Stick, Vaisala PWD22, Lufft WS100, METEK MRR-PRO) and the ERA-5 reanalysis was carried out. A vertical radar MRR-PRO is of special interest as a measuring instrument for polar regions because it can ignore surface snow transport and has proved reliability in the Antarctic environment recently. In Marine Antarctica this device can identify the height of precipitation melting and also show a number of other useful parameters. This complex of precipitation measurement instruments is planned to be used in the frames of the forthcoming YOPP-SH field campayne.</p>
<p>Synoptic-scale atmospheric circulation that transports moisture from low... more <p>Synoptic-scale atmospheric circulation that transports moisture from lower latitudes highly influences the Antarctic coastal climate, warming and moistening the lower troposphere and causing both precipitation and temperature increases. During recent decades, it has been shown that the highest warming rate over Antarctica is observed over the Antarctic Peninsula region. Heat and moisture transport from lower latitudes, particularly associated with atmospheric rivers (ARs), could play a crucial role in this warming. Among the most complex and understudied processes relate to microphysical properties of clouds and precipitation and understanding phase transitions during intense precipitation events associated with ARs and their representation in polar weather and climate models.</p><p>The goal of this research is  to investigate the temporal and spatial evolution of precipitation, including its intensity and phase transition and associated cloud properties during AR events over the Antarctic Peninsula in austral summer. We focus on two sites representing different regional and micro-climates around the Antarctic Peninsula - Escudero station, situated on King George Island at the northern tip of the peninsula, and Vernadsky station – located on Galindez Island at the western (upwind) side closer to the central part of the peninsula. Although both stations have typical maritime climate, the Vernadsky site is more affected by orographic enhancement of precipitation and cold air advection from the continent.</p><p>We use ground-based observations of meteorology, conducted during The Year of Polar Prediction Special Observing Period (YOPP-SOP) in summer 2018/2019 over the Antarctic Peninsula region and compare against ERA-5 and AMPS Polar WRF. After evaluating ERA-5 reanalysis , it is used for large-scale analysis of clouds and precipitation type. The timings of precipitation phase transitions in ERA-5 and Polar WRF are determined for the grid cells where the two stations are located. Sensitivity to microphysics parameterization in Polar WRF is tested with several double moment cloud microphysics parameterization schemes.</p><p>We analyze two cases with observed precipitation phase transitions, during the first week of December 2018. Higher precipitation amounts were observed over Vernadsky station during the first event and over Escudero during the second event. Total precipitation during the whole week is higher for Vernadsky station compared to Escudero station, related to the AR landfall position and strength, as well as the orographic enhancement at the upwind side of the Antarctic Peninsula ridge. This is confirmed by assessment of ERA-5 data. Comparison with the YOPP-SOP observations at Escudero shows that ERA-5 represents major precipitation type accurately and thus can be used for further study of precipitation microphysics. For Vernadsky station, ERA-5 showed a few cases of phase transition from snow to wet snow, associated with ARs events according to ERA-5 data; unfortunatly observations for comparison were lacking. Compared to ERA-5, Polar WRF shows a finer structure of precipitation fields disturbed by the mountains. We intend to test different parameterizations of cloud microphysics in Polar WRF with fine resolution against the complex of measurements at Vernadsky station in order to find the optimal configuration in the region to use during the upcoming winter YOPP in the Southern Hemisphere.</p>
The study presents analysis of microclimatic conditions on Galindez Island (western part of the A... more The study presents analysis of microclimatic conditions on Galindez Island (western part of the Antarctic Peninsula), in particular: seasonal variability and spatial heterogeneity. Based on land surface temperature (LST) data derived from loggers and MicroClimate Monitoring Station, we analyzed areas with active growth of local plants. Seasonal variations formed mainly under annual and semi-annual cycles, with no dependencies of amplitudes and phases form area location. LST highly correlates with air temperature and total incoming irradiance. It is emphasized that spatial orientation of relief microforms plays the most significant role for LST formation on micro-level. Using cluster analysis, it was found that temperature loggers which are located along shoreline and oriented to the north–north-east could be grouped by similar LST distribution.
<p>Synoptic-scale atmospheric circulation that transports moisture from low... more <p>Synoptic-scale atmospheric circulation that transports moisture from lower latitudes highly influences the Antarctic coastal climate, warming and moistening the lower troposphere and causing both precipitation and temperature increases. During recent decades, it has been shown that the highest warming rate over Antarctica is observed over the Antarctic Peninsula region. Heat and moisture transport from lower latitudes, particularly associated with atmospheric rivers (ARs), could play a crucial role in this warming. Among the most complex and understudied processes relate to microphysical properties of clouds and precipitation and understanding phase transitions during intense precipitation events associated with ARs and their representation in polar weather and climate models.</p><p>The goal of this research is  to investigate the temporal and spatial evolution of precipitation, including its intensity and phase transition and associated cloud properties during AR events over the Antarctic Peninsula in austral summer. We focus on two sites representing different regional and micro-climates around the Antarctic Peninsula - Escudero station, situated on King George Island at the northern tip of the peninsula, and Vernadsky station – located on Galindez Island at the western (upwind) side closer to the central part of the peninsula. Although both stations have typical maritime climate, the Vernadsky site is more affected by orographic enhancement of precipitation and cold air advection from the continent.</p><p>We use ground-based observations of meteorology, conducted during The Year of Polar Prediction Special Observing Period (YOPP-SOP) in summer 2018/2019 over the Antarctic Peninsula region and compare against ERA-5 and AMPS Polar WRF. After evaluating ERA-5 reanalysis , it is used for large-scale analysis of clouds and precipitation type. The timings of precipitation phase transitions in ERA-5 and Polar WRF are determined for the grid cells where the two stations are located. Sensitivity to microphysics parameterization in Polar WRF is tested with several double moment cloud microphysics parameterization schemes.</p><p>We analyze two cases with observed precipitation phase transitions, during the first week of December 2018. Higher precipitation amounts were observed over Vernadsky station during the first event and over Escudero during the second event. Total precipitation during the whole week is higher for Vernadsky station compared to Escudero station, related to the AR landfall position and strength, as well as the orographic enhancement at the upwind side of the Antarctic Peninsula ridge. This is confirmed by assessment of ERA-5 data. Comparison with the YOPP-SOP observations at Escudero shows that ERA-5 represents major precipitation type accurately and thus can be used for further study of precipitation microphysics. For Vernadsky station, ERA-5 showed a few cases of phase transition from snow to wet snow, associated with ARs events according to ERA-5 data; unfortunatly observations for comparison were lacking. Compared to ERA-5, Polar WRF shows a finer structure of precipitation fields disturbed by the mountains. We intend to test different parameterizations of cloud microphysics in Polar WRF with fine resolution against the complex of measurements at Vernadsky station in order to find the optimal configuration in the region to use during the upcoming winter YOPP in the Southern Hemisphere.</p>
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Papers by Denis Pishniak