10:45 〜 11:00
[AAS11-01] Data composite of airborne sulfur dioxide measurements in the upper troposphere
キーワード:sulfur dioxide, aircraft measurements, new particle formation
Sulfur dioxide (SO2) is a key aerosol precursor gas, however, only during recent years high-precision in-situ data could be obtained for the upper troposphere (UT) using airborne chemical ionization mass spectrometry. Data summaries of SO2 will be presented from a large number of campaigns performed with the research aircraft Falcon and HALO during the years 2005 to 2015 covering a geographical region from 83°N to 65°S and 105°W to 135°E and altitudes up to 15 km. The SO2 data were gridded onto a 5° latitude by 5° longitude horizontal grid with a 1-km vertical resolution. The data composites provide information about the SO2 distribution at mid-latitudes, tropical and polar regions. Median SO2 background mixing ratios in the UT range between 10-25 ppt, however, also areas with strongly enhanced SO2 mixing ratios in the UT were observed, associated with events of new particle formation. The SO2 sources and transport pathways for these specific observations will be discussed.