大气科学2012，Vol.36Issue(4)：851-862,12.DOI:10.3878/j.issn.1006-9895.2011.11162
太阳活动11年周期对ENSO事件海温异常演变和东亚降水的影响
Influence of the 11-Year Solar Cycle on the Evolution of ENSO-Related SST Anomalies and Rainfall Anomalies in East Asia
摘要
Abstract
By using NCEP/NCAR reanalysis data,the SST data,the rainfall data,and the 10.7 cm solar flux data which reflects the intensity of the solar activity,the impacts of solar activity on the seasonal SST anomalies and the related rainfall anomalies in East Asia during different phases of El Nino-Southern Oscillation (ENSO) are investigated in this paper.Particularly the authors focus on the different responses of the rainfall anomalies in East Asia in the fall of an ENSO developing year and the corresponding physical processes between the High Solar (HS) years and the Low Solar (LS) years.The SST analysis reveals that during the HS (LS) years,the intensity and scope of the SST anomalies in both the equatorial eastern Pacific and the tropical western Pacific are decreasing (increasing) in the developing phase of ENSO,and the positive correlation in the equatorial eastern Pacific weakens slowly (rapidly) in the following spring to summer.Especially in the HS phase,with the warming in the equatorial eastern Pacific,the Indian Ocean SST is found to have no apparent warming in the fall of an ENSO developing year and the Indian Ocean positive SST anomalies is significantly weaker in the following winter.The reverse situation tends to occur in the LS phase.According to the rainfall analysis results,the ENSO exerts its influence on the rainfall in China mostly in the preceding fall and the next spring.To put the solar activity in perspective,the main differences of the rainfall anomalies in East Asia occur in the preceding fall.The rainfall anomaly signals are insignificant in most of China during the preceding fall in the HS years,whereas in the LS years the reverse precipitation signals between the south and north of the Yangtze River are noticeable.Further research indicates that the rainfall differences originate from the differences of the two important circulation systems in the lower troposphere.During the LS years,the anticyclonic anomalies near the Philippines region tend to be stronger and thus intensify the supply of water vapor in the south of China.At the same time,the intensified northerly winds on the west side of the cyclone around the northern part of North China result in the less rainfall in the north of the Yangtze River.In contrast,both these two circulation systems are weaker and the associated rainfall anomalies are not significant during the HS years.The different circulation responses in the fall of an ENSO developing year may be attributed to the influences of the solar activity on the tropical SST.The results indicate that a La Nina (El Nino)-like SST pattern in the Pacific tends to be forced in the HS (LS) years,which is consistent with previous studies.Therefore,the anomalous Walker cell that rises in the tropical eastern Pacific and sinks in the tropical western Pacific is shown to be obviously weaker (stronger) in the HS (LS) phase.Compared with the HS years,in the LS years the divergence in the lower troposphere is strong in the tropical western Pacific and the induced anticyclonic circulation by the diabatic cooling is also strong.关键词
太阳活动/海温演变/ENSO/东亚降水/大气环流异常Key words
solar activity, SST evolution, ENSO (El Nino/Southern Oscillation), rainfall in East Asia, atmospheric circulation anomalies分类
天文与地球科学引用本文复制引用
周群,陈文..太阳活动11年周期对ENSO事件海温异常演变和东亚降水的影响[J].大气科学,2012,36(4):851-862,12.基金项目
国家重点基础研究发展规划项目2010CB428603,国家自然科学基金资助项目41025017 （）
