大气科学2013，Vol.37Issue(4)：815-828,14.DOI:10.3878/j.issn.1006-9895.2012.12045
一种新的El Ni(n)o海气耦合指数
New Ocean-Atmosphere Coupling Indices for El Ni(n)o
摘要
Abstract
Using the monthly mean Met Office Hadley Center sea surface temperature (SST) analyses data,Global Ocean Data Assimilation System ocean temperature data,and NCEP circulation reanalysis datasets for the period 1980-2010,the main ocean-atmosphere coupled processes over the tropical Pacific Ocean were investigated through the multivariate empirical orthogonal functions (MV-EOFs) of two thermal ocean parameters-SST and upper-ocean heat content (HC) -and five meteorological elements-sea level pressure (SLP),850-hPa u wind,850-hPa v wind,200-hPa velocity potential,and outgoing longwave radiation (OLR).Our results show that the temporal and spatial distribution of the first and second MV-EOF modes of the ocean-atmosphere elements capture the ocean-atmosphere couplings of the canonical El Ni(n)o and El Ni(n)o Modoki events,respectively.Associated with the warming center in the central and eastern tropical Pacific,the canonical El Ni(n)o phenomenon is also characterized by the "seesaw" pattern of east-west anti-phase changes in ocean-atmosphere elements such as HC,SLP,and 200-hPa velocity potential.Meanwhile,there are strong westerly anomalies in the central equatorial Pacific and anticyclonic circulation anomalies over the western North Pacific at low atmospheric levels.On the other hand,during the El Ni(n)o Modoki events,the centers of the positive anomalies of SST and HC moved west to the central equatorial Pacific,and the anomalies of SLP and 200-hPa velocity potential were characterized by a three-polar pattern.Moreover,the low-level strong westerly anomalies moved west to the east of the warm pool,and cyclonic circulation anomalies occurred over the western North Pacific.The ocean-atmosphere couplings of the two types of El Ni(n)o episodes were significantly different,which suggests that more sophisticated indices for El Ni(n)o are required to represent and separate the two events more effectively and to better identify their different atmospheric response.Here,in contrast to previously reported El Ni(n)o indices based on SST or SLP,the El Ni(n)o signal is represented by HC,and new indices based on HC are defined for the two types of events,which not only capture and characterize the two types more distinctly,for example,the 1993 El Ni(n)o and 2006 El Ni(n)o Modoki event,but better identify their ocean-atmosphere coupled process,providing a new approach to monitoring and short-term climate prediction of El Ni(n)o episodes.关键词
El Ni(n)o/El Ni(n)o Modoki/海气耦合特征/热含量指数/MV-EOFKey words
El Ni(n)o/ El Ni(n)o Modoki/ Ocean-atmosphere coupling/ Heat content indices/ MV-EOF分类
天文与地球科学引用本文复制引用
陈圣劼,何金海,吴志伟..一种新的El Ni(n)o海气耦合指数[J].大气科学,2013,37(4):815-828,14.基金项目
国家重点基础研究发展计划(973计划)项目2012CB417403,江苏高校优势学科建设工程资助项目PAPD,国家自然科学基金项目41205066 （973计划）
