open access

https://hdl.handle.net/2115/55022

Regional scale aerosol impacts on cloud microphysics over the East Asi

日本語

2014-03-31

Institute of Low Temperature Science, Hokkaido University

Low Temperature Science

72

99-111

Ⅱ. 詳細雲微物理モデルの開発と応用

Cloud microphysical properties and aerosol concentrations were measured aboard an aircraft over the East China Sea and Yellow Sea in April 2009 during the A-FORCE-2009 experiment. We sampled stratocumulus and shallow cumulus clouds over the ocean in 9 cases during 7 flights 500-900 km off the east coast of Mainland China. We show that the cloud droplet number concentration (highest 5%,Nc_max) correlates well with the accumulationmode aerosol number concentration (Na) below the clouds. We then show that Nc_max correlates partly with near-surface stratification evaluated as the difference between the sea surface temperature (SST) and 950-hPa temperature (SST－ T950). Cold air advection from China to the East China Sea was found to bring not only a large number of aerosols but also a dry and cold air mass that destabilized the atmospheric boundary layer, especially over the warm Kuroshio ocean current. Over this high-SST region, greater updraft velocities and hence greater Nc_max likely resulted. We hypothesize that the low-level static stability determined by SST and regional-scale airflow modulates both the cloud microphysics (aerosol impact on clouds) and macro-structure of clouds (cloud base and top altitudes, hence cloud liquid water path).

紀要論文

Version of Record

1880-7593