Impacts of ENSO on autumn rainfall over Yellow River loop valley in observation: Possible mechanism and stability
Impacts of ENSO on autumn rainfall over Yellow River loop valley in observation: Possible mechanism and stability
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DOI：
10.1002/jgrd.50264
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发表时间：
2013-04
期刊：
影响因子：
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通讯作者：
Chun Li;G. Zeng
中科院分区：
文献类型：
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作者：
Chun Li;G. Zeng
黄河环谷（YRLV）是中国历代主要的农业生产区之一。预测长江流域降水变率对社会经济发展具有重要意义。本文通过对中国仪器降水的统计分析，以及海温和大气资料的再分析，论证了El Niño-Southern涛动（ENSO）对长江三角洲秋季降水的影响。结果表明，长江三角洲秋季降水异常可能受到ENSO样海温模式的部分控制。在El Niño （La Niña）发展年份，长江三角洲降水偏少（偏多）。这种影响是由大气通过向西的罗斯比波对类似ENSO的海温异常强迫的响应介导的。此外，Niño3.4指数可作为长江流域秋季降水的因子，超前4-5个月。然而，秋季暴雨与ENSO之间的关系并不持续，而是通过大气环流对ENSO的年代际响应经历了80年代末以来的年代际减弱。秋季降水与ENSO关系的年代际变化可能受到气候年代际变化的调节。
The Yellow River loop valley (YRLV) is one of major agricultural production zones in many Chinese dynasties. Predicting rainfall variability in the YRLV is important for the society and the economy. This study demonstrates impacts of El Niño–Southern Oscillation (ENSO) on autumn rainfall in the YRLV based on statistical analyses of instrumental rainfall in China and reanalyzed SST and atmospheric data. Results indicate that the autumn rainfall anomaly in the YRLV may be partially controlled by the ENSO‐like sea surface temperature (SST) pattern. The YRLV rainfall is below normal (above normal) in the El Niño (La Niña) developing years. This impact is mediated by an atmospheric response to the ENSO‐like SST anomaly forcing via a westward Rossby wave. Furthermore, Niño3.4 index may be used as a factor for autumn rainfall in the YRLV region with a lead of 4–5 months. However, the relationship between the autumn YRLV rainfall and ENSO does not persist and has gone through decadal weakening since the end of 1980s via a decadal response of atmospheric circulation to ENSO. The decadal change of the relationship between the autumn YRLV rainfall and ENSO may be modulated by climate decadal shifts.