Disentangling fast and slow responses of the East Asian summer monsoon to reflecting and absorbing aerosol forcings
Disentangling fast and slow responses of the East Asian summer monsoon to reflecting and absorbing aerosol forcings
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DOI：
10.5194/acp-17-11075-2017
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发表时间：
2017-09
影响因子：
6.3
通讯作者：
Zhili Wang;Lei Lin;Meilin Yang;Yangyang Xu;Jiangnan Li
中科院分区：
文献类型：
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作者：
Zhili Wang;Lei Lin;Meilin Yang;Yangyang Xu;Jiangnan Li
抽象的。我们使用社区地球系统模式第1版（CESM 1）研究了东亚夏季风（EASM）对工业时代气溶胶强迫的反射（硫酸盐，SO4）和吸收（黑碳，BC）的总平衡响应中快速和缓慢响应的作用。结果表明，气溶胶强迫对东亚夏季风的响应存在明显的快慢之分，气溶胶对东亚夏季风的影响主要表现在气溶胶引起的海温变化对东亚夏季风的响应缓慢。东亚夏季风对SO4强迫的快速响应（FR）分量中海陆表面热力对比度的减小使东亚夏季风减弱，而对SO4强迫的慢速响应（SR）分量中对流层热力和动力结构的变化使东亚夏季风减弱更为强烈。SO4引起的总的气候调整是东亚夏季风的显著减弱和降水的减少。BC引起的快速调整增强了东亚夏季风，增强了当地的海陆热力对比，使东亚副热带急流（EASJ）北移。然而，BC引起的缓慢的气候调整，通过改变大气温度和环流，削弱了东亚夏季风。因此，东亚夏季风对BC的总响应（TR）略有增强，尤其是30° N以北。BC引起的东亚降水变化的空间格局在总响应和慢响应方面相似。这项研究强调了海洋响应气溶胶强迫在驱动东亚夏季风变化的重要性。
Abstract. We examine the roles of fast and slow responses in shaping the total equilibrium response of the East Asian summer monsoon (EASM) to reflecting (sulfate, SO4) and absorbing (black carbon, BC) aerosol forcings over the industrial era using the Community Earth System Model version 1 (CESM1). Our results show that there is a clear distinction between fast and slow responses of the EASM to aerosol forcings and the slow climate response due to aerosol-induced change in sea surface temperature (SST) plays an important role in the impacts of aerosols on the EASM. The EASM is weakened by a decrease in land–sea surface thermal contrast in the fast response (FR) component to SO4 forcing, whereas the weakening is more intensive due to the changes in tropospheric thermodynamic and dynamic structures in the slow response (SR) component to SO4. The total climate adjustment caused by SO4 is a significant weakening of the EASM and a decrease in precipitation. The BC-induced fast adjustment strengthens the EASM both by increasing the local land–sea surface thermal contrast and shifting the East Asian subtropical jet (EASJ) northwards. The BC-induced slow climate adjustment, however, weakens the EASM through altering the atmospheric temperature and circulation. Consequently, the EASM is slightly enhanced, especially north of 30° N, in the total response (TR) to BC. The spatial patterns of precipitation change over East Asia due to BC are similar in the total response and slow response. This study highlights the importance of ocean response to aerosol forcings in driving the changes of the EASM.