A COMPARATIVE ANALYSIS OF ATMOSPHERIC AND OCEANIC CONDITIONS BEFORE THE OCCURRENCE OF TWO TYPES OF EL NINO EVENTS

作者：智协飞,杨华,徐淑雯,王晓春,潘梦婷

摘要：The atmospheric and oceanic conditions before the onset of EP El Nino and CP El Nino in nearly 30 years are compared and analyzed by using 850 hPa wind,20℃isotherm depth,sea surface temperature and the Wheeler and Hendon index.The results are as follows:In the western equatorial Pacific,the occurrence of the anomalously strong westerly winds of the EP El Nino is earlier than that of the CP El Nino.Its intensity is far stronger than that of the CP El Nino.Two months before the El Nino,the anomaly westerly winds of the EP El Nino have extended to the eastern Pacific region,while the westerly wind anomaly of the CP El Nino can only extend to the west of the dateline three months before the El Nino and later stay there.Unlike the EP El Nino,the CP El Nino is always associated with easterly wind anomaly in the eastern equatorial Pacific before its onset.The thermocline depth anomaly of the EP El Nino can significantly move eastward and deepen.In addition,we also find that the evolution of thermocline is ahead of the development of the sea surface temperature for the EP El Nino.The strong MJO activity of the EP El Nino in the western and central Pacific is earlier than that of the CP El Nino.Measured by the standard deviation of the zonal wind square,the intensity of MJO activity of the EP El Nino is significantly greater than that of the CP El Nino before the onset of El Nino.

发文机构：Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters Nanjing Joint Center for Atmospheric Research Nantong Marine Environmental Monitoring Center School of Marine Science Jiangsu Engineering Technology Research Center of Marine Environment Detection

关键词：EPELNinoCPELNinoEQUATORIALZONALwindTHERMOCLINEMJO

分类号： P732.6[天文地球—海洋科学]