Interannual Variations in an Atmospheric GCM Forced by the 1970-1989 SST, Part II: Low-Frequency Var
Interannual Variations in an Atmospheric GCM Forced by the 1970-1989 SST, Part II: Low-Frequency Var
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受 1970-1989 年海温影响的大气 GCM 年际变化，第二部分：低频 Var
DOI：
10.2151/jmsj1965.69.3_271
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发表时间：
1991
影响因子：
3.1
通讯作者：
A. Kitoh
中科院分区：
文献类型：
--
作者：
A. Kitoh
本文利用1969年9月至1990年2月近全球（40*S60*N）海表温度（SST）资料，建立了一个大气环流模式。在模拟的20个冬季中，识别出了北方半球平均大气的周期型，并与观测结果进行了比较。模拟的第一模态，在纬向风在200毫巴，位势高度在500毫巴，纬向平均纬向风，波动的时间尺度约为10年。这种十年尺度的变化似乎是由于这一时期的特定SST，特别是在新几内亚东北部的热带西太平洋。东亚副热带急流的经向移动和相关的环流变化导致了这种变化。从日本周边到北方太平洋的地面气温变化主要由这种模态来解释。这种模态类似于在500毫巴观测到的位势高度的第一和第四模态。该模式的系统误差，强调在北太平洋的变化比在北大西洋的结果提取这种模式与东亚急流的纬向移动作为主导模式。此外，还模拟了南半球副热带急流向赤道移动的趋势与海温的变化趋势。
An atmospheric general circulation model is integrated, forced by the observed near-global (40*S60*N) sea surface temperatures (SST) from September 1969 to February 1990. Recurrent patterns of the rnorithly mean Northern Hemisphere atmosphere in the simulated 20 winters are identified and compared with the observations. The simulated first mode, in the zonal wind at 200 mb, geopotential height at 500 mb, and zonal-mean zonal wind, fluctuates with a time-scale of about 10 years. This decade-scale variation seems to result from the specified SST for this period particularly over the tropical western Pacific northeast of New Guinea. A meridional shift of the East Asian subtropical jet and associated circulation changes contribute to this variation. Surface air temperature variations from around Japan to the extreme northern Pacific are mostly explained by this mode. This mode resembles the observed first and fourth modes of thee geopotential height at 500 mb. The model's systematic error of emphasizing variability over the North Pacific more than that over the North Atlantic results in extracting this mode associated with the meridional shift of the East Asian jet as the leading mode. Additionally, a trend of the equatorward shift of the Southern Hemisphere subtropical jet is also simulated related to the trend in the SST.