Subseasonal variability during the South China Sea summer monsoon onset
Subseasonal variability during the South China Sea summer monsoon onset
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DOI：
10.1007/s00382-009-0679-4
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发表时间：
2010-04
期刊：
影响因子：
4.6
通讯作者：
R. Wu
中科院分区：
文献类型：
--
作者：
R. Wu
对 1998 年至 2007 年期间热带降雨测量任务（TRMM）微波成像仪（TMI）数据的分析表明，夏季季风爆发期间南海海面温度（SST）存在较大的次季节波动。这些次季节海温变化与夏季季风爆发引起的地表风和云变化引起的地表热通量异常密切相关。海温变化通过改变大气的不稳定性来反馈大气。结果表明，南海夏季风爆发涉及次季节时间尺度上的海洋-大气耦合。虽然海温对地表热通量变化的响应快速而剧烈，但海温异常与大气对流响应之间的时滞每年变化很大。次季节异常的时空演变表明，影响南海夏季风爆发的次季节变率从赤道西太平洋开始，向北传播到菲律宾海，然后向西移动到南海。这些次季节异常的传播与海气相互作用有关，包括风蒸发和云辐射对海温的影响，以及海温对赤道西太平洋低层辐合以及菲律宾海和南海大气不稳定的影响。
Analysis of the Tropical Rainfall Measuring Mission (TRMM) Microwave Imager (TMI) data for the period 1998–2007 reveals large subseasonal fluctuations in sea surface temperature (SST) of the South China Sea during the summer monsoon onset. These subseasonal SST changes are closely related to surface heat flux anomalies induced by surface wind and cloud changes in association with the summer monsoon onset. The SST changes feed back on the atmosphere by modifying the atmospheric instability. The results suggest that the South China Sea summer monsoon onset involves ocean–atmosphere coupling on subseasonal timescales. While the SST response to surface heat flux changes is quick and dramatic, the time lag between the SST anomalies and the atmospheric convection response varies largely from year to year. The spatial–temporal evolution of subseasonal anomalies indicates that the subseasonal variability affecting the South China Sea summer monsoon onset starts over the equatorial western Pacific, propagates northward to the Philippine Sea, and then moves westward to the South China Sea. The propagation of these subseasonal anomalies is related to the ocean–atmosphere interaction, involving the wind-evaporation and cloud-radiation effects on SST as well as SST impacts on lower-level convergence over the equatorial western Pacific and atmospheric instability over the Philippine Sea and the South China Sea.