Photosynthetically active solar radiation (PSR) – solar radiation within the wavelength range of 380 ¼710 nm – forms a basis of plants' life that determines their photosynthesis. No measurements of photosynthetically active solar radiation (PSR) take place in Ukraine due to the lack of standard devices. Direct, scattered and total PSR is calculated via transition measurements and coefficients, whereas total PSR is measured via sunshine duration – using the indirect method. The purpose of the research is to determine PSR and its dynamics during specific months and the warm period of the year (April-October). The components of the radiation regime within the network of actinometric and meteorological observations in Ukraine for 1986 - 2015, 1986 - 1995, 1996 - 2005, 2006 - 2015 were obtained using mathematical statistics and climatological methods. In the course of the research changes in the PSR during specific months and the warm period over specific decades were determined. During the months of the warm period over 1986 -2015, direct, diffused, total PSR and total PSR calculated via sunshine duration tend to increase from the west, northwest or Ukrainian Carpathians to the southern steppe zone and Crimea. During the warm period over 1986 - 1995, the amount of direct PSR varies within 472 ¼ 891 MJ/m², diffused radiation – 887 ¼ 1156 MJ/m², total radiation – 1457 … 1917 MJ/m², total PSR calculated based on sunshine duration – 1621 … 2056 MJ/m²; over 1996 - 2005 the amount of direct PSR varies within – 469 … 1030 MJ/m², diffused – 802 … 1004 MJ / m², total – 1305 … 1973 MJ/m², total PSR calculated based on  sunshine duration – 1654 … 2192 MJ/m²; over 2006 - 2015 the amount of direct PSR varies within 485 ¼ 1065 MJ/m², diffused radiation – 737 ¼ 951 MJ / m², total PSR – 1270 … 1977 MJ / m², total PSR calculated based on sunshine duration – 1649 … 2233 MJ / m². The increase in integrated direct solar radiation over 1996 - 2005 compared to 1986 - 1995, as well as over 2006 - 2015 compared to 1996 - 2005, led to an increase in direct PSR; the decrease in diffused solar radiation led to a decrease in diffused PSR; and ambiguous changes in the components of total solar radiation led to fluctuations in total PSR; increase in sunshine duration is accompanied by an increase in total PSR calculated based on sunshine duration. The research is relevant due to the factor of modern climate variability at the global and regional levels. The study of PSR changes is an urgent task of modern agrometeorology. It enables long-term effective planning of agricultural development.

РАДИАЦИОННЫЙ РЕЖИМ В УСЛОВИЯХ ИНТЕНСИВНЫХ ЗАСУХ 2001-2010 гг. В УКРАИНЕ Украинский научно-исследовательский гидрометеорологический институт, КиевПоказаны изменения составляющих радиационного режима в периоды интенсивных засух 2001-2010 гг. относительно стандартной климатологической нормы гг. Аномалия составляющих радиационного режима в этих условиях наблюдалась по всей территории в отдельные месяцы весны, лета и осени в течение вегетационного периода. Существенное увеличение продолжительности солнечного сияния и прямой солнечной радиации при одновременном уменьшении рассеянной не способствовали интенсивному росту суммарной радиации. Часто в весеннюю и осеннюю засуху нагревание оголенной почвы приводило к росту альбедо подстилающей поверхности. В засушливые периоды отмечалось возрастание радиационного баланса. Проведенные исследования имеют важное значение для мониторинга изменений климатических условий, а также для решения прикладных вопросов адаптации земледелия к этим изменениям.Ключевые слова: солнечная радиация; радиационный режим; интенсивная засуха; климатологическая норма. L. Rybchenko, S.Savchuk RADIATION STATE UNDER THE CONDITION OF INTENSE DROUGHTS 2001 -2010 yrs. IN UKRAINE Ukrainian hydrometeorological research institute, KyivVariations of radiation level components during the 2001 -2010 yrs. intense drought periods relative to the climatological norm 1961 -1990 yrs. has been demonstrated. Anomaly of the radiation level components in those conditions had been seen throughout entire territory during spring, summer and autumn months of the vegetation period. Significant increase in daylight and direct solar radiation along with decrease in its diffused component did not lead to a fast increase in combined total radiation. During spring and autumn droughts heating of the exposed soil surface often led to the underlying layer albedo. During the periods of drought there had been an increase in radiation levels. The conducted research has a significant importance for climate change monitoring as well as for practical applications in finding the ways to adapt farming to those changes.Keywords: solar radiation; radiation regime; intensive drought; climatological norm. Key words: solar radiation; radiation conditions; intensive drought; climatological norm.Засуха є складним природним явищем, зумовле-ним тривалим періодом збільшеної прямої сонячної радіації й температури повітря, нестачі вологи у повітрі та ґрунті, що створюють несприятливі умо-ви розвитку сільськогосподарських рослин. Пош-кодження і загибель рослин відбуваються внаслідок значного неузгодження потреби вологи в повітрі та ґрунті за підвищеної інсоляції й термічного режиму.Результатам дослідження засух на території країни присвячено ряд робіт, що оцінюють ступінь засушливості окремих періодів вегетації, вплив цих умов на стан сільськогосподарських рослин, причини їх виникнення та зміни метеорологічних величин відносно середніх значень [1][2][3][4][5][6][7][8].В умовах засухи збільшуються енергетичні мож-ливості підстильної поверхні внаслідок з...

Amid political and, consequently, economic and environmental problems engulfing Ukraine one of the today's challenges consists in studying the possibility of use of natural potential of renewable energy sources. Resources of solar radiation have no negative impact on the natural environment and human activity. Therefore development of helioenergetics and at the same time climatic substantiation of solar power plants use research become more and more important. The purpose of this article is to evaluate of the solar radiation potential opportunities for implementation of technical innovations within the territory of Ukraine and to identify prospects of helioenergetics development. Special indicators of solar radiation components for 1961-1990 s are showed. Using the method of mathematical statistics we defined a value of direct solar radiation contribution forming a part of the total radiation for the warm season (April-September). During the period of 1991-2015 an increase of solar radiation climatic resources relative to climatological standard norm of 1961-1990 was revealed. Over 2001-2015 annual direct and total solar radiation values increased even more in comparison to 1991-2000. Increase of duration of sunshine was also observed. Due to changes of radiation characteristics special indicators of solar for 1991-2015 were specified. The prospects of solar radiation use in helioenergetics proved their feasibility in Crimea, steppe zone, eastern part of forest-steppe zone and even in some parts of Polissya. Comparing to previous years, in terms of sunshine duration over 2000 hours per annum the territory expanded northward. Restrictions on innovations implementation apply to western forest-steppe zone and mountainous areas of Ukrainian Carpathians. Increase of solar radiation regime components determining the feasibility of solar power energy resources form the basis for their countrywide use.