Optical and microphysical parameters of aerosol in the near-water atmosphere of the White Sea as assessed from the data of simultaneous ship-borne and coast-based measurements in August 2006

Abstract

Simultaneous measurements of the optical and microphysical parameters of near-water aerosol were performed over the White Sea in August 2006 during the 80th cruise of the research vessel Professor Shtockman rom onboard the vessel and in the coastal zone (on the territory of the Unskii beacon, the southern coast of Dvina Bay). The spatial-temporal variability of the concentrations of aerosol and soot in the marine atmosphere are studied, and the geophysical factors determining this variability are analyzed. The conditions of extremely low aerosol content in the atmosphere with concentrations of aerosol and soot of 1.2–1.7 µg/m3 and 0.01 µg/m3, respectively, were observed both in ship-borne and coast-based measurements on August 20–23 in anticyclonic conditions in the Arctic air mass. Such values are comparable with the values observed in open ocean areas. The regions of the central area of the White Sea, Kandalaksha Bay, and the Unskii beacon can be considered as background during the period of the experiment, according to the contents of aerosol and soot. The results of the comparison of simultaneous ship-borne and coast-based measurements of the concentrations of aerosol and soot revealed a similarity of their interday variability, which is evidence of the fact that the peculiarities of temporal variations, at least during the experiment, have a regional scale and are principally determined by the dynamics of synoptic processes of the change of the air masses.