Preferred response of the East Asian summer monsoon to local and non-local anthropogenic sulphur dioxide emissions
Preferred response of the East Asian summer monsoon to local and non-local anthropogenic sulphur dioxide emissions
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DOI：
10.1007/s00382-015-2671-5
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发表时间：
2016-03-01
期刊：
影响因子：
4.6
通讯作者：
Wilcox, Laura J.
中科院分区：
文献类型：
--
作者：
Dong, Buwen;Sutton, Rowan T.;Wilcox, Laura J.
在这项研究中，一个国家的最先进的气候模式（HadGEM 2-ES），其中包括地球系统的组件，如相互作用的化学和8种对流层气溶胶考虑气溶胶的直接，间接和半直接的影响，大气成分已被用来调查本地和非本地的人为二氧化硫排放对东亚夏季风（EASM）的影响。该研究的重点是快速响应（包括陆面反馈，但没有海表温度反馈）的突然变化，从亚洲和欧洲的排放量。在第1-40天，对亚洲和欧洲排放的初步反应显示出很大的差异。对亚洲排放的反应涉及对亚洲硫酸盐负担的直接影响，通过气溶胶辐射和气溶胶云相互作用对短波能量收支产生直接影响。这些变化导致东亚地区变冷，东亚夏季风减弱。相比之下，欧洲的排放对亚洲的硫酸盐负担没有显着的影响，但它们会导致对流层中部的冷却和干燥的欧洲部门。然而，随后，这种寒冷和干燥的异常平流进入亚洲，在那里它引起亚洲和西北太平洋（WNP）的大气和地面反馈，这也削弱了东亚夏季风。尽管亚洲和欧洲的二氧化硫排放对当地气溶胶负荷的扰动非常不同，但从第40天起，东亚地区陆海热对比、大气环流和当地降水的大尺度变化模式具有相似的结构，表明了一种优选的响应，并表明这两个地区的排放可能有助于观察到的东亚夏季风减弱。亚洲上空对流层的变冷变干，以及西北太平洋上空的增暖增湿，减小了亚洲大陆与周边海洋之间的海陆热力对比。这导致亚洲海平面气压（SLP）异常偏高，而西北太平洋海平面气压异常偏低，这与东亚夏季风减弱有关。在响应这两个地区的排放变暖和增湿的WNP起着重要的作用，并决定了响应的时间尺度。
In this study, the atmospheric component of a state-of-the-art climate model (HadGEM2-ES) that includes earth system components such as interactive chemistry and eight species of tropospheric aerosols considering aerosol direct, indirect, and semi-direct effects, has been used to investigate the impacts of local and non-local emissions of anthropogenic sulphur dioxide on the East Asian summer monsoon (EASM). The study focuses on the fast responses (including land surface feedbacks, but without sea surface temperature feedbacks) to sudden changes in emissions from Asia and Europe. The initial responses, over days 1-40, to Asian and European emissions show large differences. The response to Asian emissions involves a direct impact on the sulphate burden over Asia, with immediate consequences for the shortwave energy budget through aerosol-radiation and aerosol-cloud interactions. These changes lead to cooling of East Asia and a weakening of the EASM. In contrast, European emissions have no significant impact on the sulphate burden over Asia, but they induce mid-tropospheric cooling and drying over the European sector. Subsequently, however, this cold and dry anomaly is advected into Asia, where it induces atmospheric and surface feedbacks over Asia and the Western North Pacific (WNP), which also weaken the EASM. In spite of very different perturbations to the local aerosol burden in response to Asian and European sulphur dioxide emissions, the large scale pattern of changes in land-sea thermal contrast, atmospheric circulation and local precipitation over East Asia from days 40 onward exhibits similar structures, indicating a preferred response, and suggesting that emissions from both regions likely contributed to the observed weakening of the EASM. Cooling and drying of the troposphere over Asia, together with warming and moistening over the WNP, reduces the land-sea thermal contrast between the Asian continent and surrounding oceans. This leads to high sea level pressure (SLP) anomalies over Asia and low SLP anomalies over the WNP, associated with a weakened EASM. In response to emissions from both regions warming and moistening over the WNP plays an important role and determines the time scale of the response.