Scripps Institution of Oceanography, University of California, San Diego, La Jolla, California 92093, USA.
Atmospheric Science and Global Change Division, Pacific Northwest National Laboratory, Richland, Washington 99354, USA.
Nat Commun. 2017 May 11;8:15333. doi: 10.1038/ncomms15333.
Eastern China has experienced severe and persistent winter haze episodes in recent years due to intensification of aerosol pollution. In addition to anthropogenic emissions, the winter aerosol pollution over eastern China is associated with unusual meteorological conditions, including weaker wind speeds. Here we show, based on model simulations, that during years with decreased wind speed, large decreases in dust emissions (29%) moderate the wintertime land-sea surface air temperature difference and further decrease winds by -0.06 (±0.05) m s averaged over eastern China. The dust-induced lower winds enhance stagnation of air and account for about 13% of increasing aerosol concentrations over eastern China. Although recent increases in anthropogenic emissions are the main factor causing haze over eastern China, we conclude that natural emissions also exert a significant influence on the increases in wintertime aerosol concentrations, with important implications that need to be taken into account by air quality studies.
近年来，由于气溶胶污染的加剧，中国东部地区经历了严重且持续的冬季雾霾事件。除了人为排放外，中国东部冬季的气溶胶污染还与异常的气象条件有关，包括较弱的风速。在这里，我们基于模型模拟表明，在风速降低的年份，灰尘排放的大量减少（29%）会缓和冬季海陆表面气温差，并在中国东部平均降低风速 -0.06（±0.05）米/秒。灰尘引起的较低风速会加剧空气停滞，约占中国东部气溶胶浓度增加的 13%。尽管近年来人为排放的增加是导致中国东部地区雾霾的主要因素，但我们的结论是，自然排放也对冬季气溶胶浓度的增加产生了显著影响，这一事实需要纳入空气质量研究中进行考虑。
