Detecting climate change in Ukraine: trends, prediction and extreme events

<p>In this study the trends and variations in 25 extreme temperature and precipitation indices<br>defined by ETCCDI, are examined using trend method, probability distribution analysis and<br>spatial statistics for periods of 71 to 137 years for 16 stations evenly distributed in Ukraine. Data<br>on the indices were obtained from www.ecad.eu.<br>Since 1981, temperature has increased by about 1&#186;C in all stations in question relative to the<br>period of 1945-1980. Analysis of the temperature indices indicates that during the 20th and the<br>beginning of the 21th century there is significant warming which is particularly pronounced in<br>annual mean and annual maximum temperatures. Occurrence of more summer days, warm days<br>and tropical nights and warm spell duration reached the record highest level, and conversely<br>occurrence of frost and ice days, cold days and cold spell duration fall to a record low for the last<br>three decades in the most of study territory.<br>Since 1981, precipitation amount has grown by 30-50 mm relative to the period of 1945-1980 for<br>the most of Ukrainian territory, except Uzhhorod and Uman where precipitation amount has<br>remained the same. For Ukraine average, an increase in maximum daily and maximum 5 days<br>precipitation amount, the maximum number of consecutive wet days, heavy and very heavy<br>precipitation days, and a decrease in the maximum number of consecutive dry days are observed<br>for the last three decades.<br>The analysis of the spatial distribution of trend of precipitation and temperature indices showed<br>that there are large differences between regions of Ukraine, and coherence of spatial distribution<br>of trends of various indices is low.<br>Spectral analysis and harmonic regression techniques were used to derive simulated and<br>predicted (2019-2050) values of annual precipitation and annual mean temperature and four<br>indices such as maximum value of daily maximum temperature, minimum value of daily<br>minimum temperature, the highest 1-day precipitation amount and maximum number of<br>consecutive dry days for some stations such as Kerch (the Crimean Peninsula), Kyiv (situated in<br>north-central Ukraine along the Dnieper River), Lubny (Dnieper Lowland), Lviv and Shepetivka<br>(Podillia Upland), Uzhhorod (Transcarpathia), Uman (Dnieper Upland).<br>Annual mean temperature and maximum value of daily maximum temperature were predicted to<br>increase by 0.33&#176;C per decade in the period of 2019-2050 with respect to 1981-2018, while<br>minimum value of daily minimum temperature was predicted to grow slightly faster (by 0.43-<br>0.63&#186;C per decade).<br>Precipitation was predicted to increase for the stations in question by 20-66 mm up to 2050<br>relative to 1981-2018 and conversely maximum number of consecutive dry days will slightly<br>decline except Lubny where increase in an aridity index was predicted. In the next three decades<br>changes in maximum daily precipitation will be various: in Shepetivka and Kyiv such<br>precipitation will be decreased and in other stations increasement in such precipitation will be up<br>to 6 mm till 2050 with respect to 1981-2018.</p>