Dual effects of the winter monsoon on haze-fog variations in eastern China
Dual effects of the winter monsoon on haze-fog variations in eastern China
复制标题
冬季风对中国东部霾雾变化的双重影响
DOI：
10.1002/2016jd026296
复制
发表时间：
2017-06-16
影响因子：
4.4
通讯作者：
Zhou, Yang
中科院分区：
文献类型：
--
作者：
Liu, Qian;Sheng, Lifang;Zhou, Yang
已有研究表明，东亚冬季风与中国冬季霾事件之间存在负相关关系。冬季季风通过平流带走气溶胶颗粒并通过寒潮提供清洁的空气来减少雾霾。然而，在亚季节时间尺度上，霾-雾事件的发生频率与典型的冬季风指数没有相关性。结果表明，与西伯利亚高压相关的平静天气的积累和维持作用对冬季霾事件的发展同样重要，西伯利亚高压也是季风环流系统的一部分。相关分析表明，灰霾的亚季节变化与西伯利亚高压强度密切相关(r=0.49)。西伯利亚高压可能通过降低近地面风速和增强层结稳定性来增加霾事件的发生。为了量化冬季风的这些不同影响对霾事件变化的贡献，我们分别分析了寒潮活动和平静天气期间的霾事件，并对比了这两种影响在不同时间尺度上的相对贡献。在亚季节尺度上，西伯利亚高压的影响是寒潮的2.0倍；在年际尺度上，寒潮的影响是西伯利亚高压的2.4倍。这一研究揭示了东亚冬季风对中国东部冬季霾变化的双重影响，对季风与霾事件的关系有了更全面的认识。
Previous studies have revealed a negative correlation between the East Asian winter monsoon and wintertime haze-fog events in China. The winter monsoon reduces haze-fog by advecting away aerosol particles and supplying clean air through cold waves. However, it is found that the frequency of haze-fog events on subseasonal time scales displays no correlation with typical winter monsoon indices. The results show that the accumulating and maintaining effects of calm weather related to the Siberian High, which is also a part of the monsoon circulation system, are equally important for the development of haze-fog events during winter. Correlation analysis indicates that subseasonal variations in haze-fog are closely related to the intensity of the Siberian High (r=0.49). The Siberian High may increase the occurrence of haze-fog events by reducing the near surface wind speed and enhancing the stratification stability. To quantify the contribution of these diverse effects of the winter monsoon on the variations in haze-fog events, we analyzed haze-fog events during periods of cold wave activity and calm weather separately and contrasted the relative contributions of these two effects on different time scales. On the subseasonal scale, the effect of the Siberian High was 2.0 times that of cold waves; on the interannual scale, the effect of cold waves was 2.4 times that of the Siberian High. This study reveals the dual effects of the East Asian winter monsoon on wintertime haze-fog variations in eastern China and provides a more comprehensive understanding of the relationship between the monsoon and haze-fog events.