Characterization of aerosols and CCN over the Yellow Sea measured onboard the Gisang 1 research vessel in spring 2018 and 2019

Aerosol effects on climate change have been known to have large uncertainty because of insufficient measurement data. Aerosol observation studies in East Asia are particularly lacking. The Yellow Sea, located between the Chinese continent and the Korean Peninsula, is an ideal place for investigating continental influence from both sites.

As an effort to investigate such influence, submicron aerosol number concentration, aerosol size distribution and CCN number concentration were measured over the Yellow Sea on board the Gisang 1 research vessel in spring 2018 and 2019. Two condensation particle counters (CPC; TSI 3776 and TSI 3772) measured the number concentration of aerosols larger than 3 nm and 10 nm (N_CN3 and N_CN10, respectively). A scanning mobility particle sizer (SMPS) measured the aerosol size distribution with a range of 10-500 nm in mobility diameter. A CCN counter (CCNC; DMT CCN-100) measured CCN number concentration (N_CCN) at several supersaturations (0.2, 0.4, 0.6, 0.8 or 1.0%).

On average, N_CN10 and N_CCN at 0.6% supersaturation over the Yellow Sea in spring 2018 were 6053 cm^-3 and 4350 cm^-3, respectively. Such relatively high concentration for ship measurements suggests severe continental influence. Aerosol and CCN number concentration and aerosol size distribution showed clear temporal and spatial variation. Aerosol number concentration showed wind dependency. N_CN3 and N_CN10 were generally low under southerly wind conditions. Aerosol number concentration and size distribution were also influenced by meteorological conditions (e.g., relative humidity). Average values of N_CN10 and N_CCN at 0.6% supersaturation in spring 2019 were slightly higher than those in spring 2018 (7428 cm^-3 and 4680 cm^-3, respectively). Detailed analysis of aerosols and CCN in spring 2019 is currently underway. CCN closure study (estimating CCN number concentration from aerosol size distribution) over the Yellow Sea will also be carried out. Comprehensive analysis results will be shown at the conference.