Stable isotopic composition of atmospheric precipitation on the Crimean Peninsula and its controlling factors

A first systematic study of the isotopic composition of precipitation on the Crimean Peninsula was carried over the period of 58 months at two stations located on the Crimean Piedmont (Simferopol, 290 m a.s.l.) and on the northern slope of the Main Range of the Crimean Mountains (Chatyr-Dag, 980 m a.s.l.). Oxygen and hydrogen isotope values of these stations yielded a Crimean Local Meteoric Water Line: δ2H = 7.3 δ18O + 4.8; r2 = 0.97. The isotopic composition of precipitation at the two stations is partly (25% and 39%, respectively) correlated with the local air temperature, but the degree of this correlation shows large temporal variability. No correlation between isotopic composition and precipitation amount was observed. Far-field controls, such as changing sources, supplying moisture for the Crimean precipitation, or varying strength of the North Atlantic Oscillation do not influence the isotopic composition of precipitation in Crimea on these short time scales.