Seasonal variation features of aerosol optical depth （AOD） over East China and India in association with the Asian monsoon system are investigated, based on the latest AOD data derived from the Moderate Resolution I...Seasonal variation features of aerosol optical depth （AOD） over East China and India in association with the Asian monsoon system are investigated, based on the latest AOD data derived from the Moderate Resolution Imaging Spec-troradiometer （MODIS） aboard the Terra satellite, the NCEP Final （FNL） Operational Global Analysis data, the Cli-mate Prediction Center （CPC） Merged Analysis of Precipitation （CMAP） data, and the NCEP/NCAR reanalysis data from March 2000 to February 2017. The results indicate that AOD in East China is significantly larger than that in India, especially in spring. The seasonal mean AOD in East China is high in both spring and summer but low in fall and winter. However, the AOD averaged over India is highest in summer and lower in spring, fall, and winter. Ana-lysis reveals that AOD is more closely related to changes in surface wind speed in East China, while no obvious rela-tion is found between precipitation and the AOD distribution on the seasonal timescale. As aerosols are mainly dis-tributed in the atmospheric boundary layer （ABL）, the stability of the ABL represented by Richardson number （Ri） is closely correlated with spatial distribution of AOD. The upper and lower tropospheric circulation patterns signific-antly differ between East China and India, resulting in different effects on the AOD. The effect of advection associ-ated with lower tropospheric circulation on the AOD and the influence of convergence and divergence on the AOD distribution play different roles in maintaining the AOD in East China and India. These results improve our under-standing of the mechanism responsible for and differences among the aerosol changes in East China and India.展开更多
基金Supported by the National(Key)Basic Research and Development(973)Program of China(2011CB403406)Priority Academic Program Development(PAPD)of Jiangsu Higher Education Institutions
文摘Seasonal variation features of aerosol optical depth （AOD） over East China and India in association with the Asian monsoon system are investigated, based on the latest AOD data derived from the Moderate Resolution Imaging Spec-troradiometer （MODIS） aboard the Terra satellite, the NCEP Final （FNL） Operational Global Analysis data, the Cli-mate Prediction Center （CPC） Merged Analysis of Precipitation （CMAP） data, and the NCEP/NCAR reanalysis data from March 2000 to February 2017. The results indicate that AOD in East China is significantly larger than that in India, especially in spring. The seasonal mean AOD in East China is high in both spring and summer but low in fall and winter. However, the AOD averaged over India is highest in summer and lower in spring, fall, and winter. Ana-lysis reveals that AOD is more closely related to changes in surface wind speed in East China, while no obvious rela-tion is found between precipitation and the AOD distribution on the seasonal timescale. As aerosols are mainly dis-tributed in the atmospheric boundary layer （ABL）, the stability of the ABL represented by Richardson number （Ri） is closely correlated with spatial distribution of AOD. The upper and lower tropospheric circulation patterns signific-antly differ between East China and India, resulting in different effects on the AOD. The effect of advection associ-ated with lower tropospheric circulation on the AOD and the influence of convergence and divergence on the AOD distribution play different roles in maintaining the AOD in East China and India. These results improve our under-standing of the mechanism responsible for and differences among the aerosol changes in East China and India.
