Submicron aerosol size distribution measurements in the city of Seoul, and coastal and marine environments around South Korea

Submicron aerosol size distributions and total particle (i.e., condensation nuclei, CN) concentrations were measured continuously from September 2004 at the campus of Yonsei University located at the central part of Seoul. The instruments, TSI SMPS-3936L10 and CPC-3010, were installed at an office in the sixth floor of a building and the sample air was drawn from a window. The height of the building and the relatively low traffic in the campus may qualify these measurements as a background aerosol distribution in a highly urbanized city. The highest monthly average CPC (total particle) concentration was 37000 cm-3 in February 2005. The trend of wintertime increase was also obvious in the SMPS integrated concentrations but these were only 60-70 percent of the CPC concentrations. There was rather clear diurnal trend of near dawn (~4 AM) minima and morning peak (~8 AM) and a secondary peak in the evening (~8 PM) for both CPC and SMPS data. As a part of the Atmospheric Brown Clouds East Asian Regional Experiment (ABC-EAREX2005), measurements were also made on board the research vessel Kisang 2000 during the cruise from March 2 to March 10, 2005 over the South Sea of Korea and over the Korean sector of the Yellow Sea. Ship track was 60 km or more away from the coast. After the ship measurements the instruments were placed at the Gosan ABC Observatory in Jeju Island, for almost four weeks starting from March 11, 2005 to measure coastal aerosol distributions and inter-comparisons with other instruments. The average CPC and SMPS concentrations were 6700 cm-3 and 4400 cm-3, respectively, for the ship measurements, and 6000 cm-3 and 4000 cm-3 for the same two measurements at Gosan. However, when remote marine environments near Jeju Island were segregated from the ship measurements, the CPC and SMPS concentrations were 3600 cm-3 and 2400 cm-3, respectively. CPC and SMPS measurements will also be made over the South China Sea during another ship cruise from Jeju Island to Shanghai in September 2005. These data will also be presented in the conference. Focus will be on air mass characteristics of total particle concentrations and submicron aerosol size distributions in the marine environment of northeast Asia.