Seasonal variability of zonal heat advection in the mixed layer of the tropical Pacific  

作　　者：官聪 陈永利 王凡 

机构地区：[1]Institute of Oceanology,Chinese Academy of Sciences [2]Key Laboratory of Ocean Circulation and Waves,Chinese Academy of Sciences [3]University of Chinese Academy of Sciences

出　　处：《Chinese Journal of Oceanology and Limnology》2013年第6期1344-1355,共12页中国海洋湖沼学报（英文版）

基　　金：Supported by the National Basic Research Program of China(973 Program)(No.2012CB417401);the CAS Strategic Priority Research Program(No.XDA10010104)

摘　　要：Zonal heat advection （ZHA） plays an important role in the variability of the thermal structure in the tropical Pacific Ocean, especially in the western Pacific warm pool （WPWP）. Using the Simple Ocean Data Assimilation （SODA） Version 2.02/4 for the period 1958-2007, this paper presents a detailed analysis of the climatological and seasonal ZHA in the tropical Pacific Ocean. Climatologically, ZHA shows a zonal- band spatial pattern associated with equatorial currents and contributes to forming the irregular eastern boundary of the WPWP （EBWP）. Seasonal variation of ZHA with a positive peak from February to July is most prominent in the Nifio3.4 region, where the EBWP is located. The physical mechanism of the seasonal cycle in this region is examined. The mean advection of anomalous temperature, anomalous advection of mean temperature and eddy advection account for 31%, 51%, and 18% of the total seasonal variations, respectively. This suggests that seasonal changes of the South Equatorial Current induced by variability of the trade winds are the dominant contributor to the anomalous advection of mean temperature and hence, the seasonality of ZHA. Heat budget analysis shows that ZHA and surface heat flux make comparable contributions to the seasonal heat variation in the Nifio3.4 region, and that ZHA cools the upper ocean throughout the calendar year except in late boreal spring. The connection between ZHA and EBWP is further explored and a statistical relationship between EBWP, ZHA and surface heat flux is established based on least squares fitting.Zonal heat advection(ZHA) plays an important role in the variability of the thermal structure in the tropical Pacific Ocean,especially in the western Pacific warm pool(WPWP).Using the Simple Ocean Data Assimilation(SODA) Version 2.02/4 for the period 1958–2007,this paper presents a detailed analysis of the climatological and seasonal ZHA in the tropical Pacific Ocean.Climatologically,ZHA shows a zonal- band spatial pattern associated with equatorial currents and contributes to forming the irregular eastern boundary of the WPWP(EBWP).Seasonal variation of ZHA with a positive peak from February to July is most prominent in the Ni o3.4 region,where the EBWP is located.The physical mechanism of the seasonal cycle in this region is examined.The mean advection of anomalous temperature,anomalous advection of mean temperature and eddy advection account for 31%,51%,and 18% of the total seasonal variations,respectively.This suggests that seasonal changes of the South Equatorial Current induced by variability of the trade winds are the dominant contributor to the anomalous advection of mean temperature and hence,the seasonality of ZHA.Heat budget analysis shows that ZHA and surface heat flux make comparable contributions to the seasonal heat variation in the Ni o3.4 region,and that ZHA cools the upper ocean throughout the calendar year except in late boreal spring.The connection between ZHA and EBWP is further explored and a statistical relationship between EBWP,ZHA and surface heat flux is established based on least squares fitting.

关 键 词：zonal heat advection SEASONALITY tropical Pacific Ocean warm pool ocean circulation 

分 类 号：P461.2[天文地球—大气科学及气象学]