Features of atmospheric phenomena’s dynamics in Kharkiv region

Abstract

The article presents the results of rainfall, hail, precipitation and fogs’ frequency study in Kharkiv region during the period 2001-2014 by means of statistical analysis. The calculations were carried out on the basis of monthly rainfall data at the meteorological stations of the region (Lozova, Kharkiv, Zolochiv, Kupyansk, Izyum, Krasnograd, Bogodukhiv, Velykyi Burluk, Slobozhanske, Kolomak) for the period 1961-2014, the number and duration of fogs. The conditions of their formation, distribution and development on the territory of Kharkiv region characterizing the annual and seasonal changes have been determined. All types of atmospheric precipitation are observed on the investigated area, namely long-term deposits prevailing throughout the year (liquid (103%) and solid (68%), amongst streams - liquid (121%). Long-term precipites are characteristic of the autumn period, when atmospheric phenomena are formed. Fogs, mist, storms, thunderstorms and lightnings are observed in the spring and summer (30% and 74% respectively). In the winter, it is possible to observe the same probability that liquid and snow, ice cover (24% and 20% respectively) mix , frosts (46%). Most often, (35%) of showers happen within one day, 30% of cases occur for 2 and 3-5 days. Sometimes they are observed for several days. There is a great variety of heavy rains on the territory of Kharkiv region, where you can expect 3-5 days with showers for a year. As a rule, the rains can be accompanied by hail and thunderstorms. The hail is a more rare phenomenon than a thunderstorm, it falls predominantly during the warmer years of the powerful cumulonimbus clouds with a strong upright movement. Hail is formed in the conditions of a large variety of synoptic processes. In 53% of cases, hail is associated with cold fronts, and 47% - correspond to the internal processes of the mass. Hailstones with a diameter of 20 mm and more cause significant damage to the economy, It has been established that over the past fifteen years there has been an increasing tendency in the number of rains, showers and hail of varying intensity on the territory of Kharkiv region. The largest number of fogs was recorded in the north of the oblast (Kharkiv, Zolochiv and Bogodukhiv). Most fogs are observed in the autumn-winter period and make up more than 60 days a year.