Periodicity of dry phenomena on the South coast of Crimea

Abstract

Long-term periodicity of arid phenomena on the South coast of Crimea was investigated based on the data of observations at the meteorological station in the Katsiveli settlement for the period from 1984 to 2020. Considered is the change in the annual total duration of dry periods (10 days or more without precipitation). The recurrence of days with abnormal atmospheric precipitation (more than 30 mm per day) in warm and cold periods of the year was studied. The relationship between changes in atmospheric precipitation, air temperature and humidity, and solar activity (Wolf numbers) is traced. The moisture coefficient of Vysotsky-Ivanov, the dryness index, and the hydrothermal coefficient of Selyaninov for warm periods of the year have been determined. The revealed tendencies of increasing temperature and the dryness index along with decreasing precipitation and the moisture coefficient, may be associated with the observed decrease in solar activity, which contributes to decreasing cyclonic activity, decreasing upper and lower cloudiness and, consequently, to decreasing precipitation.