ACIDITY AND CHEMICAL COMPOSITION OF SUMMER PRECIPITATION WITHIN THE MOSCOW REGION

Abstract

Spatial variability of acidity and chemical composition of precipitation within theMoscowcity and theMoscowregion is analyzed basing on the results of the experiment carried out during summer 2013. The results were compared with the reference data from the MSU Meteorological Observatory where practically each precipitation event during more than 30 years was sampled and analyzed (ion composition and acidity). The synoptic processes were described and the technique of reverse trajectories of particles was applied. It was demonstrated that a little bit higher pH values are typical for the eastern part of theMoscowregion. Acid rains could occur both in the centre of the city and in the clean remote areas. The general composition of ions in theMoscowregion is characterized by predominance of Ca cations in combination with various anions, i.e. hydrogen carbonates, chlorides and sulfates. Unlike this, for already about 10 years the chlorides are predominant anions in precipitation sampled at the MSU Meteorological Observatory. The ratio of main ions is spatially more stable than the mineralization and the pH values. Generally rather diverse pattern of distribution of mineralization and pH values, particularly within the megapolis area is most probably an indicator of prevailing influence of local sources on the precipitation pollution.