气象学报2011，Vol.25Issue(4)：506-516,11.DOI:10.1007/s13351-011-0409-9
Connections Between Different Types of El Ni(n)o and Southern/Northern Oscillation
Connections Between Different Types of El Ni(n)o and Southern/Northern Oscillation
摘要
Abstract
It has long been acknowledged that there are two types of El Ni(n)o events,i.e.,the eastern Pacific El Ni(n)o (EE) and the central Pacific El Ni(n)o (CE),according to the initial position of the anomalous warm water and its propagation direction.In this paper,the oceanic and atmospheric evolutions and the possible mechanisms of the two types of El Ni(n)o events were examined.It is found that all the El Ni(n)o events,CE or EE,could be attributed to the joint impacts of the eastward advection of warm water from the western Pacific warm pool (WPWP) and the local warming in the equatorial eastern Pacific.Before the occurrence of CE events,WPWP had long been in a state of being anomalous warm,so the strength of eastward advection of warm water was much stronger than that of EE,which played a major role in the formation of CE.While for the EE events,most contribution came from the local warming of the equatorial eastern Pacific.It is further identified that the immediate cause leading to the difference of the two types of El Ni(n)o events was the asynchronous variations of the Southern Oscillation (SO) and the Northern Oscillation (NO) as defined by Chen in 1984.When the transition from the positive phase of the NO (NO+) to NO- was prior to that from SO+ to SO-,there would be eastward propagation of westerly anomalies from the tropical western Pacific induced by NO and hence the growth of warm sea surface temperature anomalies in WPWP and its eastward propagation.This was followed by lagged SO-induced weakening of southeast trade winds and local warming in the equatorial eastern Pacific.These were conducive to the occurrence of the CE.On the contrary,the transition from SO+ to SO- leading the transition of NO would favor the occurrence of EE type events.关键词
eastern Pacific El Ni(n)o/central Pacific El Ni(n)o/Southern Oscillation/Northern OscillationKey words
eastern Pacific El Ni(n)o/central Pacific El Ni(n)o/Southern Oscillation/Northern Oscillation引用本文复制引用
彭京备,张庆云,陈烈庭..Connections Between Different Types of El Ni(n)o and Southern/Northern Oscillation[J].气象学报,2011,25(4):506-516,11.基金项目
Supported by the Key Tcchnology Research and Dcvelopment Program of China (2009BAC51B02),Special Public Welfare Research Fund for Meteorological Profession of China Meteorological Administration (GYHY201106015),and National Natural Science Foundation of China (40775037). （2009BAC51B02）
