中东太平洋热带辐合带降水统计特征及其与厄尔尼诺的相关性  

Statistical characteristics of ITCZ precipitation in the central-eastern Pacific and its correlation with El Nio

作　　者：朱金双 刘宇迪 

机构地区：[1]国防科技大学气象海洋学院,南京211101

出　　处：《地球物理学报》2018年第1期80-90,共11页Chinese Journal of Geophysics

基　　金：国家自然科学基金(41175089)资助

摘　　要：利用GPCP(Global Precipitation Climatology Project)与CMAP(CPC Merged Analysis of Precipitation)降水资料以及欧洲天气预报中心月平均SST(Sea Surface Temperature)资料,统计分析了中东太平洋热带辐合带(Centre and Eastern Pacific ITCZ,CEP-ITCZ)降水在两类厄尔尼诺年的基本特征及其与两类厄尔尼诺的相关性.结果表明:在普通年份,CEP-ITCZ平均位置约为7.6°N,强度7.25mm/day,东部型厄尔尼诺年位置偏南约2.9°,强度增强1.9mm/day;而中部型厄尔尼诺年位置偏南仅有0.2°,强度增强1.7 mm/day.不同Nio海区对CEPITCZ位置与强度的影响具有显著差异,与CEP-ITCZ位置相关性最大的海区为超前一个月的Nio 3海区,而与CEP-ITCZ强度相关性最大的海区则为超前一个月的Nio 3.4(8月—次年2月)或Nio 4(3—7月)海区,影响CEP-ITCZ位置的海区主要为东太平洋,影响CEP-ITCZ强度的海区则为中太平洋.此外,CEP-ITCZ位置和强度的异常对SST异常的敏感性均在4月份达到最强,11月份达到最弱.This study was based on the monthly mean precipitation data from the Global Precipitation Climatology Project （GPCP） and CPC Merged Analysis of Precipitation （CMAP） and monthly mean sea surface temperature （SST） data from the European Centre for Medium-Range Weather Forecasts （ECMWF）. The purpose was to investigate the characteristics of ITCZ precipitation in the central-eastern Pacific as well as its correlation with two types of El Nio. The results show that the latitude where the central-eastern Pacific ITCZ （CEP-ITCZ） exists is 7.6N with intensity 7.25 mm/day during usual years. By contrast, the CEP-ITCZ is located farther south by about 2.9 （0.2） with intensity stronger by about 1.9 mm/day （1.7 mm/day） during the eastern （central） Pacific El Nio. The discrepancies of the CEP-ITCZ anomalies between two types of El Nio events can be attributed to sea areas, which can influence the position or the intensity of CEP-ITCZ, respectively. There is relatively strong correlation between the CEP-ITCZ position and the SST anomaly in the Nio 3 area ahead of one month, while the intensity anomaly of the CEP-ITCZ from March to July （from August to next February） closely correlates with the SST anomaly in the Nio 4 （Nio 3.4） area ahead of one month. The area with major effects on the position （intensity） of the CEP-ITCZ tends to lie in the eastern （central） Pacific. Both the position and intensity of the CEP-ITCZ are the most （least） sensitive to the SST anomaly in the corresponding Nio area in April （November）.

关 键 词：中东太平洋 热带辐合带(ITCZ) 厄尔尼诺 

分 类 号：P433[天文地球—大气科学及气象学]