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北太平洋海温对ENSO事件响应的持续性OA北大核心CSTPCD

The persistence of the North Pacific SST response to ENSO events

中文摘要英文摘要

北太平洋海温的异常变化对海洋生态系统以及全球天气和气候都有重要影响.北太平洋海温主要受ENSO的影响,并可以从ENSO盛期冬季一直延续到ENSO衰减年春季,存在明显的持续性.然而,2000年前ENSO的影响仅能维持至次年 2月,2000年后却能持续至 5月,其持续性呈明显的年代际增强.基于再分析数据探讨这一年代际变化的特征以及可能的物理机制.结果表明,ENSO事件对冬、春季北太平洋海温影响持续性在 2000年后的增强,主要受到北太平洋区域经向平流反馈及海表热通量反馈控制.2000年前,由ENSO激发的遥相关波列在春季已经减弱,热通量的反馈作用使得海温上升.而在 2000年之后,冬季偏西的海温异常使赤道对流可以在次年春季长时间维持在国际日期变更线附近,持续激发大气遥相关波列导致北太平洋上空在春季仍然存在显著的气旋性环流异常,并通过经向平流反馈及热通量反馈使局地海温维持偏低状态,对ENSO产生持续响应,增强ENSO事件对其影响的持续性.

The anomalies of Sea Surface Temperature(SST)over the North Pacific have significant impacts on marine ecosystems and global weather and climate.The North Pacific SST is primarily influenced by ENSO and shows a clear persistence.However,its duration manifests an interdecadal enhancement.Before 2000,the impact of ENSO only lasted until February of the following year;after 2000,however,it could extend until May.Based on reanalysis data,this study explores the characteristics of this interdecadal change and the potential physical mechanisms behind it.The results indicate that the enhanced persistence of ENSO impact on the winter—spring North Pacific SST is mainly controlled by the meridional advection feedback and the sea surface heat flux feedback over the North Pacific.Before 2000,the teleconnection triggered by ENSO had already weakened in spring,leading to high SST due to the heat flux feedback.However,after 2000,the SST anomaly to the west of its normal location during winter allowed equatorial convection to persist near the dateline until the following spring.The persistent convection continuously triggered remote atmospheric teleconnection and resulted in significant cyclonic circulation anomalies over the North Pacific.These anomalous circulations finally led to low SST through meridional advection feedback and heat flux feedback,and thereby enhanced the persistence of the North Pacific SST response to ENSO events.

渠畅;祁莉

南京信息工程大学气象灾害教育部重点实验室/气象灾害预报预警与评估协同创新中心,南京,210044

大气科学

北太平洋海温年代际变化遥相关热带降水

North Pacific SSTInterdecadal variationTeleconnectionTropical precipitation

《气象学报》 2024 (004)

411-426 / 16

国家重点研发计划项目(2022YFF0801602).

10.11676/qxxb2024.20230127

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