We used a chemical transport model to investigate the long-term trends of sulfur deposition in East Asia during 1981-2005. The model reproduced the observed spatial distributions in East Asia of the rate of wet deposition of non-seasalt sulfate (nss-SO 4 2-), volume-weighted mean concentrations of nss-SO 4 2- in precipitation, precipitation, and concentrations in air of gaseous sulfur dioxide and particulate nss-SO 4 2-. The model also reproduced well observed seasonal variations and long-term trends of wet deposition of nss-SO 4 2- in Japan from 1988 to 2005. The increasing rate of wet deposition of nss-SO 4 2- in Japan during 1991-2005 was demonstrated with 99.9% significance for both observed and modeled data. The annual rate of total (wet + dry) sulfur deposition in Japan increased from 15.6 Gmol S y -1 in 1981-1985 to 23.9 Gmol S y -1 in 2001-2005 in response to both increasing contributions from Chinese emissions and the eruption of Miyakejima volcano in 2000. During that 25-year period, approximately 2.1% of the sulfur from Chinese emissions was deposited in Japan. Over the same period, the rate of deposition of sulfur in East Asia increased gradually from 14.2 mmol S m -2 y -1 to 24.0 mmol S m -2 y -1, and the contribution of emissions from China to total sulfur deposition in East Asia increased from 65% to 77%. The contribution of Miyakejima volcano was 3% during 2001-2005. The increase in the sulfur deposition rate was remarkably high on the North China Plain, around Guangzhou, and south of Chongqing. The rate of increase in East Asia was greatest in winter, although the rate of sulfur deposition was highest in summer. Sulfur flux from China to Japan increased by a factor of 2.5 at altitudes of 0-3000 m from 1981 to 2005.
All Science Journal Classification (ASJC) codes
- Environmental Science(all)
- Atmospheric Science