| 2015/2016年超强El Nio局地海气特征及其特殊性 |
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| 引用本文： | 张文君,耿新.2015/2016年超强El Nio局地海气特征及其特殊性[J].大气科学学报,2016,39(6):778-787. |
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| 作者姓名： | 张文君 耿新 |
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| 作者单位： | 南京信息工程大学 气象灾害教育部重点实验室/气候与环境变化国际合作联合实验室/气象灾害预报预警与评估协同创新中心, 江苏 南京 210044;南京信息工程大学 气象灾害教育部重点实验室/气候与环境变化国际合作联合实验室/气象灾害预报预警与评估协同创新中心, 江苏 南京 210044 |
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| 基金项目： | 国家自然科学基金资助项目（41675073）；国家公益性行业（气象）专项（GYHY20150613；GYHY20140622）；江苏省高校自然科学研究资助项目（13KJB170013）；江苏省青蓝工程和六大人才高峰项目 |
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| 摘 要： | 利用NOAA海表温度和NCEP/NCAR大气环流等全球再分析资料,讨论了2015/2016年超强El Nio事件局地海气过程的演变特征,并与1982/1983和1997/1998年两次强El Nio事件做了对比分析。结果表明,2015/2016年El Nio在峰值强度、持续时间、累计海温距平等指标上都略强于前两次El Nio,可视为有完整气象观测纪录以来的最强事件;与前两次事件相比,2015/2016年El Nio海温异常中心位置明显偏西,热带东太平洋海温相对较冷而中太平洋更暖,由于热带对流对海温的非线性响应,赤道东太平洋降水相对较弱,中太平洋则显著偏多,这在El Nio当年12月至次年4月尤为明显;此外,在前两次El Nio的成熟期至衰减期,中太平洋大气响应都存在明显的南移特征,西风异常和对流中心都从赤道南移到了5°S以南。而2015/2016年中太平洋大气响应一直位于赤道附近,南移特征相对较弱,ENSO和年循环相互作用的组合模态相比前两次较弱,西北太平洋反气旋的强度也弱于前两次。这主要是由于2015年冬季至2016年春季,热带太平洋暖海温异常位置偏西,中太平洋海温异常明显强于前两次,叠加气候平均态海温之后,赤道南北两侧海温都高于对流阈值,对流旺盛,这大大削弱了大气响应的经向移动和ENSO组合模态的强度。
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| 关 键 词： | 2015/2016年超强El Niño ENSO组合模态 大气响应南移 西北太平洋反气旋 |
| 收稿时间： | 2016/8/25 0:00:00 |
| 修稿时间： | 2016/10/24 0:00:00 |
Characteristics and particularity of local air-sea processes for the 2015/2016 super El Niño event |
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| ZHANG Wenjun and GENG Xin.Characteristics and particularity of local air-sea processes for the 2015/2016 super El Niño event[J].大气科学学报,2016,39(6):778-787. |
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| Authors: | ZHANG Wenjun and GENG Xin |
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| Institution: | Key Laboratory of Meteorological Disaster, Ministry of Education(KLME)/Joint International Research Laboratory of Climate and Environment Change(ILCEC)/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters(CIC-FEMD), Nanjing University of Information Science & Technology, Nanjing 210044, China;Key Laboratory of Meteorological Disaster, Ministry of Education(KLME)/Joint International Research Laboratory of Climate and Environment Change(ILCEC)/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters(CIC-FEMD), Nanjing University of Information Science & Technology, Nanjing 210044, China |
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| Abstract: | Based on the latest monthly global reanalyzed NOAA(National Oceanic and Atmospheric Administration) sea surface temperature(SST) and NCEP(National Centers for Environmental Prediction)/NCAR(National Center for Atmospheric Research) atmospheric circulation data,we analyzed the characteristics of the local air-sea processes for the 2015/2016 super El Niño event,and the differences with previous(1982/1983 and 1997/1998) super El Niño events are also discussed.The 2015/2016 super El Niño event can be regarded as the strongest on record,since the corresponding indices of El Niño duration,peak intensity and accumulated SST anomaly remain the strongest among the existing three super El Niño events.The location of the tropical SST anomaly was displaced further west compared with the 1982/1983 and 1997/1998 events.As a result,the SST of the 2015/2016 El Niño event was colder in the tropical eastern Pacific and warmer in the central Pacific than that of the previous two super El Niño events.Due to nonlinear responses of the convectional precipitation to the SST anomaly,precipitation anomalies were weaker in the tropical eastern Pacific and much stronger in the central Pacific during the 2015/2016 El Niño event than those during the previous two super El Niño events,which was particularly evident from the El Niño December to the following April.Moreover,the 1982/1983 and 1997/1998 super El Niño events exhibited obvious southward shifts of the atmospheric responses from the equator to 5°S in the tropical central Pacific during the mature-to-decay phase.However,the precipitation and the westerly wind anomalies during the same phase of the 2015/2016 event were mainly located near the equator and the meridional movements were not as robust as those during the 1982/1983 and 1997/1998 events.The intensities of the ENSO combination mode,which results from the interaction between ENSO and the annual cycle,were also weaker during the 2015/2016 event than those during the previous two super El Niño events,and so was the anomalous western North Pacific anticyclone.Further analyses reveal that these particular phenomena in the 2015/2016 super El Niño were the consequence of the westward shift of the SST anomaly in the tropical central Pacific from winter 2015 to spring 2016.The relatively cold climatological SST north of the equator increased and exceeded the convection threshold,which favored the convection activities both south and north of the equator and led to the weakened meridional movement of the atmospheric responses. |
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| Keywords: | 2015/2016 super El Niño ENSO combination mode southward shift of atmospheric response western North Pacific anticyclone |
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