气象学报2025，Vol.83Issue(5)：1217-1228,12.DOI:10.11676/qxxb2025.20240113
热带北大西洋海温与降水关系的季节性特征及其物理机制
Seasonality of the SST-precipitation relationship over the tropical North Atlantic and possible mechanisms
摘要
Abstract
Based on the monthly Sea Surface Temperature(SST)data from the Met Office Hadley Centre,the Global Precipitation Climatology Project monthly precipitation data,and the historical simulations from Coupled Model Intercomparison Project Phase 6(CMIP6)climate models,the present work investigates the seasonality of the SST-precipitation relationship over the tropical North Atlantic and possible role of ENSO(El Niño-Southern Oscillation).It is found that the relationship of SST anomalies in the tropical North Atlantic with local precipitation exhibits a remarkable seasonality.During spring and summer,there is a significant positive correlation between SST and precipitation in this region,indicating a strong local ocean-atmosphere coupling.In contrast,in autumn and winter,the ocean-atmosphere coupling weakens significantly,and almost no significant precipitation response to SST is detected.Further analysis reveals that this seasonality is mainly associated with the seasonal cycle of the background SST and local SST variability in the tropical North Atlantic.Despite cooler background SST in spring,the strong SST variability during this season makes SST easy to exceed the convection threshold and thus induces precipitation anomalies.In summer,the warm background SST favors the enhanced local ocean-atmosphere coupling.The relatively weak SST variability in autumn weakens the local precipitation response,despite a relatively warm SST background.The cooler background SST in winter results in a weak ocean-atmosphere coupling.ENSO has a significant influence on spring SST and precipitation anomalies in the tropical North Atlantic.As a result,the strong local SST anomalies in spring are more likely to actively trigger local convective responses under ENSO forcing.However,in other seasons,the impact of ENSO on SST anomaly in the tropical North Atlantic is relatively small,and thus there is almost no difference in local ocean-atmosphere coupling in the tropical North Atlantic with or without ENSO SST forcing.These findings emphasize the critical role of spring and summer tropical North Atlantic SST anomalies in local convection and associated climate impacts,which is important for short-term climate prediction related to the tropical North Atlantic SST.关键词
热带北大西洋/海温/降水/季节性/ENSOKey words
Tropical North Atlantic/SST/Precipitation/Seasonality/ENSO分类
大气科学引用本文复制引用
徐蓉蓉,张文君,胡苏琼..热带北大西洋海温与降水关系的季节性特征及其物理机制[J].气象学报,2025,83(5):1217-1228,12.基金项目
国家自然科学基金项目(42125501). （42125501）
