Inter-annual variation of the spring haze pollution over the North China Plain: Roles of atmospheric circulation and sea surface temperature
Inter-annual variation of the spring haze pollution over the North China Plain: Roles of atmospheric circulation and sea surface temperature
复制标题
华北平原春季霾污染的年际变化：大气环流和海面温度的作用
DOI：
10.1002/joc.5842
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发表时间：
2019-02-01
期刊：
影响因子：
--
通讯作者：
Cohen, Jason Blake
中科院分区：
文献类型：
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作者：
Chen, Shangfeng;Guo, Jianping;Cohen, Jason Blake
雾霾污染是中国面临的严重空气质量问题。以往对北中国平原的研究主要集中在分析北方冬季的灰霾天气。然而，春季雾霾的变化及其相关因素仍不清楚。本文研究了春季灰霾的年际变化，该年际变化由NCP上空的湿度校正干消光系数(DEC)表示。在DEC高的年份，NCP及其周边地区出现了明显的正DEC异常。与之相对应的是，东北亚地区出现了显著的反气旋异常，并在NCP上空引发了显著的东南风异常。异常的东南风降低了风速，增加了相对湿度，为气溶胶污染物的积累和生长提供了有利的气象条件。进一步分析表明，北大西洋涛动(NAO)通过向下传播的大气波列，对东北亚地区反气旋异常的形成有贡献。此外，副热带东北大西洋海表温度(SST)正异常也可能影响DEC的变化。线性正压模式试验进一步证实了副热带东北大西洋海温异常在东北亚地区反气旋异常和北半球南风异常中的重要作用，这些异常是由东传大气波列触发的。这项研究支持了NAO和北大西洋海温可能是春季频繁观测的NCP霾变化的潜在预报因子的观点。
Haze pollution is a serious air quality issue in China. Previous studies over the North China Plain (NCP) mainly focused on analysing the haze during boreal winter. However, the variation in haze during spring and the related factors remain unclear. This study investigates inter-annual variation of the spring haze, which is represented by the humidity-corrected dry extinction coefficient (DEC) over the NCP. During high DEC years, pronounced positive DEC anomalies appear over the NCP and its surrounding regions. Correspondingly, a notable anticyclonic anomaly is observed over Northeast Asia, inducing significant southeasterly wind anomalies over the NCP. The anomalous southeasterly winds reduce wind speed and increase relative humidity, which provides favourable meteorological conditions for accumulation and growth of aerosol pollutants. Further analysis shows that the North Atlantic Oscillation (NAO) contributes to the formation of anticyclonic anomalies over Northeast Asia via downstream propagating atmospheric wave trains. Additionally, positive sea surface temperature (SST) anomalies over the subtropical northeastern Atlantic Ocean may also impact the DEC variation. The linear barotropic model experiment further confirms the important role of subtropical northeastern Atlantic SST anomalies in contributing to the anomalous anticyclone over Northeast Asia and southerly wind anomalies over the NCP region, which are triggered via eastwards propagating atmospheric wave trains. This study gives support to the idea that the NAO and the North Atlantic SST may be potential predictors for the frequently observed springtime NCP haze variation.