Кафедра екології

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Assessing Climate Aridity Trends in Southern Ukraine during 1991-2020
(2023) Boychenko, Svitlana; Kuchma, Tetyana; Maidanovych, Nadiia; Myronova, T.
Assessment of Climate Aridity Trends in the Southern Region of Ukraine was conducted using data meteostations for the period 1991-2020. The analysis of climate aridization trends over the past 30 years in the study region has revealed a notable intensification of this process, especially in recent years. The hottest summer months occurred in 1992, 1999, 2001-2003, 2007, 2010, 2012, and 2017-2019. These periods were marked by anomaly high temperatures, dry winds, extended non-rainfall periods, and low air humidity, often reaching as low as 30%. Over the past 30 years, from March to October, the Southern Region experienced an average of 203±6 non-rainfall days, with a trend indicating an increase by an average of 0.4±0.1 days per 10 years. Conversely, the number of days with relative humidity up to 30% on the March–October time scale averaged 41±16 days, with a tendency to increase by 1.2±0.7 days per 10 years. The highest occurrence of days with relative humidity up to 30%, on average in the region, is typically observed in July and August (7 and 10 days per month, respectively). To assess climate aridity and calculate drought severity for vegetation were used a satellite-derived Vegetation Health Index (VHI). Drought indices derived from the summed VHI values in August for the years 2007, 2018, and 2020 in the Southern Region of Ukraine are presented.
Assessing the influence of height above sea level and geographic coordinates on surface air temperature values for a plain part of Ukraine
(2022) Boychenko, Svitlana; Maidanovych, N.; Zabarna, O.
The main principles of the methodology for assessing the influence of height above sea level and geographic coordinates (latitude and longitude) on the values of annual and average monthly temperature in Ukraine for the period 1991-2020 are proposed. Thus, the annual surface air temperature decreases by an average: of 0.69oС per 100 m of height above sea level, of 0.51oС with a shift of one degree of latitude to the north, and of 0.08oС with a shift of one degree of longitude to the East. The altitudinal and latitudinal gradients of temperature have the greatest spatiotemporal variability and the longitudinal gradient has the smallest one. These gradients generate "microclimatic noise" of temperature. On their basis, a regional semi-empirical model of the spatiotemporal distribution of the average monthly temperature for the plain part of Ukraine for the period 1991-2020 was worked out. A comparison of values of model average annual and monthly temperature for 58 meteostations in Ukraine with their actual values showed a statistically significant correlation. Additionally, validation of semi-empirical model average monthly temperature for 10 other stations was carried out.
Assessment of aridization of climatic conditions on the Crimean Peninsula in summer using ground and satellite data
(2022) Boychenko, Svitlana; Kuchma, Tetiana
Climate vulnerability of the Crimean Peninsula is assessed based on the temperature and precipitation changes for the period 1991-2021 and satellite-derived drought index (VHI) variations for the period 2001-2021. There is an increase of temperature on average by 0.78±0.01 oC per 10 years in summer, and a slight change in precipitation in June and July (within 2±1%). While in August there is a decrease of the precipitation amount by 10-12%. According to analysed data, the most severe drought condition manifestation on the Crimean Peninsula over the last twenty years was observed in 2007, 2017, 2018 and 2020. In the central part of the Crimean peninsula, which belongs to the climatic zone of Steppe Crimea, arid conditions had the greatest manifestation and distribution (zones with extreme and severe drought conditions are observed). Minor areas in the mountainous part of the Crimea also have signs of arid conditions, but for the most part the condition of vegetation is satisfactory in this area. In percentage terms, in 2007 VHI values of extreme and severe drought occupied 57% and 20% of the peninsula’s area accordingly, as well 10% and 29% in 2017, 7% and 22% in 2018 and 11% and 26% in 2020.
A century-long tendency of change in surface air temperature on the territory of Ukraine
(2024) Boychenko, Svitlana; Maidanovych, Nadiia
Early historical meteorological observations of air surface temperature on 11 meteostations in Ukraine (since 1808) were analyzed. However, since a larger number of stations have time series of temperature starting in 1821—1825, for more reliable estimates of the linear trend, the period 1824—2021 was required. The trend is 0.78 °C per 100 years for this period. According to the analysis of meteorological data, the average annual surface air temperature on the territory of Ukraine in 1900—2021 was 8.6±0.9 °C. However, for the more recent period of 1991—2020, it increased to 9.5±0.9 °C. The temperature in Ukraine exhibited an increase of 1.31±0.42 °С per 100 years during 1900—2021. Over the last 30 years, a more pronounced increase in annual surface air temperature, by 0.79±0.08 °C per decade, was observed. Changes in the temperature regime exhibit spatio-temporal patterns. In most parts of Ukraine in 1900—2021, a temperature increase is within 1.5—2.0 °C per 100 years. Simultaneously, some parts of northern, northwestern, and eastern regions, as well as the Vinnytska and Zaporizhzhska oblasts, are characterized by more intense warming, reaching 2.0—2.5 °C per 100 years, in contrast to southwestern, southern regions, and the territories adjacent to the Ukrainian Carpathians, where the temperature rise is within 1.0—1.5 °C per 100 years. Temperature anomalies from 1900 to 2021 indicate the lowest annual averages occurred in 1933, 1956, 1976, 1985, and 1987, while the highest annual averages were observed in 2007, 2015, 2019, and 2020. Between 1900 and 2021, the average monthly air temperature in Ukraine substantially increased in colder months (from October to March), ranging from 0.7 to 2.0 °C per century. Simultaneously, warmer months (from April to September) saw an elevation ranging from 1.0 to 1.9 °C per century. In the 1991—2020 norm, an overall warming trend of 0.5—1.3 °C per decade was observed. Notably, January showed a slight decrease in the warming rate, with a trend value of –0.1 °C per decade. An indicator of the seasonality of climatic conditions is the amplitude of surface air temperature (A). In Ukraine, the average amplitude A was 12.7±1.1 °C from 1900 to 2021 and 12.5±0.8 °C from 1991 to 2020. Analysis of the temperature amplitude over the 20th century and the early 21st century revealed a general tendency of decreasing A values (the trend is –0.5 °C per 100 years), primarily due to warming in the colder months. However, from 1991 to 2020, the trend in A values was only –0.001 per decade, attributed to a significant temperature rise during the warmer months. Based on the analyses of the Johansson-Ringleb continentality indices in Ukraine, the indices’ values were determined to be 59.3±3.7 for the period spanning from 1900 to 2021, and 59.0±3.4 from 1991 to 2020. An overarching trend indicates a decrease by 0.4 % per 100 years. However, from 1991 to 2020, a contrasting pattern emerged, revealing an increase by 6.4 % per decade. The three scenarios of annual average surface temperature changes in Ukraine (SSP1- 2.6, SSP2-4.5, and SSP3-7.0) relative to pre-industrial levels in the late 19th century, based on greenhouse emissions scenarios by 2100, are discussed.
Change in the Water Surface Area of Reservoir of the Crimean Peninsula According to Radar Satellite data Sentinel-1 for the Period from October 2014 to August 2022
(2022) Kuchma, Tetyana; Boychenko, Svitlana
According to Sentinel–1 radar satellite data, there is a tendency to reduce the area of the water mirror in all reservoirs of the Crimean Peninsula, analyzed in this study, compared to their water surface area in 2015. On average, the area of the water mirror decreased by 34% in 2021. In three reservoirs, the area of the water mirror decreased by more than 60% compared to 2015: Frontove, Taiganske, and Mizhhirske reservoirs. The tendency to reduce the water surface area begins to manifest clearly in mid–2019 and continues until 2021. Also, a retrospective analysis of satellite images for 2015–2021 showed that the Simferopol reservoir of water surface area had been reduced on average by ~ 20% compared to 2015. Changes in the Water Surface Area of Simferopol and Feodosiya Reservoir for the Period from October 2014 to August 2022 were presented. A retrospective analysis of satellite images for the period from March 2015 to August 2022 showed that the Simferopol and Feodosiya Reservoirs of water surface area had been reduced on average by ~20% and ~30% (according) compared to 2015.
Climate change and fires in the Ukrainian Polissia region
(2023) Karamushka, Victor; Kuchma, Tetyana; Boychenko, Svitlana; Nazarova, Olga
Climate change accompanied by anomalously high temperatures and a decrease in precipitation during the warm season can have serious consequences for Ukrainian Polissia, including an increased risk of forest and peat fires, deterioration of ecosystem integrity, changes of biodiversity patterns, etc. An average temperature increase of 0.60°C per decade was observed in the Ukrainian Polissia region along with an annual precipitation decrease ranging from 2 to 4% over the period from 1990 to 2021. The prevailing weather conditions in 2020 included snowless warm winter, warm arid spring (in particular, in March and April), and certain accompanying synoptic conditions (e.g., high wind speeds up to 15–20 m/s). Such conditions contributed to the forest fires and a powerful dust storms in most regions of the Ukrainian Polissia. During the spring 2020, more than half of the territory of Ukrainian Polissia was exposed to fires. The climatic conditions of spring 2022 were not as dry as in 2020, however, due to the war, fires engulfed a significant part of the territory of Kyiv and Chernihiv Polissia. Analysis of the spatial distribution of the fire frequency in the regions of Ukrainian Polissia in 2020 and 2022 (based on the satellite data) points out the dominance of different fire-promoting factors: in 2020, it was weather anomalies, in 2022 - human activities (armed hostilities).
Climate impact drivers provoke fires in protected areas of Polissia
(2022) Karamushka, Victor; Boychenko, Svitlana; Nazarova, Olha
The purpose of the research was to analyze the dynamic of the climate impact drivers (CIDs) in the Regional Landscape Park Mizhrichynskyi (RLPM), Chernihiv Region, and to determine changes occurred in the protected areas affected by CIDs using the satellite monitoring data. It is shown that in the region for the period 1991-2021, such CIDs as the average annual surface temperature have a tendency to increase (the rate is 0.68оС per 10 years, average annual value is 8.4±0.9оС), while atmospheric precipitation tends to decrease by 5-7% per 10 years (-24 mm per 10 years, an average annual value is 581±94 mm). During periods with minimal precipitation and high temperatures, conditions favorable for the development of fires arise. Such conditions were observed in 2020. As a result of the fire in the RLPM (April 2020), more than 650 hectares of forest ecosystems were affected. Using the satellite monitoring data, the area of the territory covered by the fire was determined, and using the Normalized Difference Vegetation Index as an indicator, the development of successional processes in this territory was recorded. Field studies confirm the occurrence of pioneer species in the fires. The list of these species includes but not restricted to Viola tricolor, Pinus sylvestris, Salix rosmarinifolia, Corynephorus canescens, Oenothera biennis L., Hieracium pilosella L.

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Browsing Кафедра екології by Author "Boychenko, Svitlana"

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