Source Contributions of Sulfate Aerosol over East Asia Estimated by CMAQ-DDM
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- 作者：Syuichi Itahashi ; Itsushi Uno ; Soontae Kim
- 刊名：Environmental Science & Technology (ES&T)
- 出版年：2012
- 出版时间：June 19, 2012
- 年：2012
- 卷：46
- 期：12
- 页码：6733-6741
- 全文大小：576K
- 年卷期：v.46,no.12(June 19, 2012)
- ISSN：1520-5851
文摘
We applied the decoupled direct method (DDM), a sensitivity analysis technique for computing sensitivities accurately and efficiently, to determine the source-receptor relationships of anthropogenic SO2 emissions to sulfate aerosol over East Asia. We assessed source contributions from East Asia being transported to Oki Island downwind from China and Korea during two air pollution episodes that occurred in July 2005. The contribution from China, particularly that from central eastern China (CEC), was found to dominate the sulfate aerosols. To study these contributions in more detail, CEC was divided into three regions, and the contributions from each region were examined. Source contributions exhibited both temporal and vertical variability, largely due to transport patterns imposed by the Asian summer monsoon. Our results are consistent with backward trajectory analyses. We found that anthropogenic SO2 emissions from China produce significant quantities of summertime sulfate aerosols downwind of source areas. We used a parametric scaling method for estimating anthropogenic SO2 emissions in China. Using column amounts of SO2 derived from satellite data, and relationships between the column amounts of SO2 and anthropogenic emissions, 2009 emissions were diagnosed. The results showed that 2009 emissions of SO2 from China were equivalent to 2004 levels.