摘要
El Nio可通过海—气相互作用遥相关型影响东亚季风,进而影响中国气候,是中国短期气候最重要的预测指标之一。典型的El Nio事件通常在春、夏季开始,在秋、冬季成熟,在下一年的春、夏季消退,考虑到海—气作用的滞后效应,El Nio事件甚至可以在消退时期对东亚大气环流系统造成影响。因此,利用中国160站的逐月降水资料、NCEP/NCAR再分析资料以及美国NOAA提供的全球海温数据,对比分析了2015/2016年和1997/1998年典型El Nio衰减年我国夏季降水和东亚环流特征的差异,并讨论了造成差异的可能原因。结果表明:1)2016年和2008年夏季降水都大范围偏多,2016年夏季降水异常更为集中,但降水强度不及1998年。2)2016年降水的季节推进特征不明显。1998年6—8月的降水逐渐从南向北推进,与传统的季风降水演变进程较为一致。3)2016年和2008年我国夏季降水的差异与副热带高压的变化有直接的关系。1998年6—7月副热带高压较2016年同期偏西偏南,而2016年8月副热带高压更为偏西并明显比气候平均偏北。4)1997/1998年El Nio事件中的赤道西太平洋异常冷海温比较强盛,而2015/2016年基本表现为偏暖,可能是造成1998年6—7月副热带高压较2016年同期偏西偏南的原因。
The El Nino Southern Oscillation is the most significant interannual scale signal of global tropical air sea systems. It can affect the East Asian monsoon system through the teleconnection form of air-sea interaction,follow-ing which it has an impact on climate in China. Therefore,El Nino is one of the most important predictors of short-term climate in China. El Nino events typically begin in the spring and summer,mature in the autumn and winter,and subside in the spring and summer of the following year. Considering the hysteretic response of the at-mosphere to the ocean,El Nino can have an influence on the atmospheric circulation over East Asia,and even the precipitation in China in decaying years of El Nino.
Therefore,the anomalies of summer rainfall in China and atmospheric circulation over East Asia in the decaying years of two super El Nino events（ 2015/2016 and 1997/1998） were compared,in order to improve the understanding of the relationship between El Nino events and climate anomalies in China,as well as to provide a reference for short-term climate prediction. Specifically speaking,the percentage of precipitation anomaly in China,water vapor flux anomaly,anomaly of water vapor flux divergence,geopotential height anomaly,western end of the ridge and position of the ridge of the subtropical high and sea surface temperature anomaly in the decaying years of two super El Nino events were analyzed,by means of the monthly mean precipitation data of 160 meteorological observation stations in China,along with the circulation index,Indian Ocean Basin-wide Warming index from the National Climate Center of China Meteorological Administration,monthly mean geopotential height,wind,specific humidity and surface pressure from the American National Centers for Environmental Prediction,and the Optimum Interpolation Sea Surface Temperature version 2 data from the American National Oceanic and Atmospheric Administration.
The results are as follows. Summer rainfall frequently occurs on a large scaleand flood disaster i
出处
《大气科学学报》
CSCD
北大核心
2016年第6期835-844,共10页
Transactions of Atmospheric Sciences
基金
国家自然科学基金资助项目(41641042
41675039
41305039
41375047
41305079
91537213)
江苏高校优势学科建设工程项目(PAPD)
关键词
EL
Nino衰减年
东亚大气环流
中国降水异常
El Nino decaying year
atmospheric circulation over East Asia
precipitation in China
anomaly
