The Role of Long-Term Trends in Seasonal Predictions: Implication of Global Warming in the NCEP CFS
The Role of Long-Term Trends in Seasonal Predictions: Implication of Global Warming in the NCEP CFS
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DOI：
10.1175/2009waf2222231.1
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发表时间：
2009-08
影响因子：
2.9
通讯作者：
M. Cai;Chul‐Su Shin;H. Dool;Wanqiu Wang;S. Saha;Arun Kumar
中科院分区：
文献类型：
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作者：
M. Cai;Chul‐Su Shin;H. Dool;Wanqiu Wang;S. Saha;Arun Kumar
摘要本文分析了NCEP气候预报系统（CFS）25年（1982-2006）回顾性季节气候预测数据集的长期地面气温趋势，该模型将大气温室气体固定在1988年的浓度水平。虽然CFS的季节预报倾向于非常密切地跟踪观测到的年际变化，但CFS的预报和观测之间存在着明显的时间依赖性差异，1988年之前存在暖模式偏差，1992-94年期间存在短暂的暖偏差，之后出现冷偏差。从温暖到寒冷的偏差的趋势可能是由于没有包括在CFS中的人为温室气体的观测增加，而温暖的偏差在1992-94年反映了1991年皮纳图博火山喷发释放的异常气溶胶的情况下。对CFS季节气候预测的技术分析表明，1997-98年的厄尔尼诺事件对气候变暖有显著影响。
Abstract This paper analyzes long-term surface air temperature trends in a 25-yr (1982–2006) dataset of retrospective seasonal climate predictions made by the NCEP Climate Forecast System (CFS), a model that has its atmospheric greenhouse gases fixed at the 1988 concentration level. Although the CFS seasonal forecasts tend to follow the observed interannual variability very closely, there exists a noticeable time-dependent discrepancy between the CFS forecasts and observations, with a warm model bias before 1988 and a cold bias afterward except for a short-lived warm bias during 1992–94. The trend from warm to cold biases is likely caused by not including the observed increase in the anthropogenic greenhouse gases in the CFS, whereas the warm bias in 1992–94 reflects the absence of the anomalous aerosols released by the 1991 Mount Pinatubo eruption. Skill analysis of the CFS seasonal climate predictions with and without the warming trend suggests that the 1997–98 El Nino event contributes significantly to...