Aircraft Measurements of Aerosol Properties in Pollution Layers Transported into the Arctic in Spring and Summer Seasons

Abstract

In order to improve knowledge on the properties, evolution and climate impact of the tropospheric aerosol in the Arctic region, a number of aircraft experiments have been performed in the Arctic in the last few years, which contributed to the IPY core project POLARCAT. Here we report on results of the two ASTAR (Arctic Study on Tropospheric Aerosol and Radiation) aircraft field campaigns based in Longyearbyen/Svalbard, in May 2004 and March/April 2007, and the POLARCAT-GRACE campaign based in Kangerlussuaq/Greenland in July 2008. In 2004 the AWI Dornier-228 Polar 4 and in the later campaigns the DLR Falcon research aircraft were carrying an instrument package for in situ measurements of aerosol microphysical properties consisting of condensation particle counters, a differential mobility particle sizer system, optical aerosol spectrometer probes and an absorption photometer. In the 2007 and 2008 experiments, air mass tracers (CO, O3, SO2, NOy) were measured on the aircraft as well. In this contribution, we give an overview of the observations in pollution layers found during various flights in different altitude regimes of the Polar troposphere. We focus on aerosol properties in these layers, and use tracer composition and FLEXPART analysis of air mass transport to assess possible sources (biomass burning, different industrial sources) and transport routes.