Salinity effects on the 2014 warm “Blob” in the Northeast Pacific

作     者：Hai Zhi Pengfei Lin Rong-Hua Zhang Fei Chai Hailong Liu 

作者机构：College of Atmospheric Sciences Nanjing University of Information Science and Technology Nanjing 210044 China State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics Institute of Atmospheric Physics (IAP) Chinese Academy of Sciences Beijing 100029 China College of Earth Sciences University of Chinese Academy of Sciences Beijing 100049 China Key Laboratory of Ocean Circulation and Waves Institute of Oceanology Chinese Academy of Sciences Qingdao 266071 China State Key Laboratory of Satellite Ocean Environment Dynamics Second Institute of Oceanography Ministry of Natural Resources Hangzhou 310012 China School of Marine Sciences University of Maine Orono 04469-5706 USA 

出 版 物：《Acta Oceanologica Sinica》 (海洋学报（英文版）)

年 卷 期：2019年第38卷第9期

页      面：24-34页

核心收录：

学科分类：0710[理学-生物学] 0908[农学-水产] 07[理学] 0707[理学-海洋科学] 

基　　金：The National Key Research and Development Program for Developing Basic Sciences under contract Nos 2016YFC1401601 and 2016YFC1401401 the National Natural Science Foundation of China under contract Nos 41376026,41690122,41690120 and 41475101 the NSFC–Shandong Joint Fund for Marine Science Research Centers under contract No.U1406401 the NSFC Innovative Group Grant under contract No.41421005 the Taishan Scholarship 

主　　题：warm “Blob” mixed layer depth surface and subsurface salinity anomalies 

摘      要：A significant strong, warm “Blob(a large circular water body with a positive ocean temperature anomaly) appeared in the Northeast Pacific (NEP) in the boreal winter of 2013 2014, which induced many extreme climate events in the US and Canada. In this study, analyses of the temperature and salinity anomaly variations from the Array for Real-time Geostrophic Oceanography (Argo) data provided insights into the formation of the warm “Blob over the NEP. The early negative salinity anomaly dominantly contributed to the shallower mixed layer depth (MLD) in the NEP during the period of 2012 2013. Then, the shallower mixed layer trapped more heat in the upper water column and resulted in a warmer sea surface temperature (SST), which enhanced the warm “Blob. The salinity variability contributed to approximately 60% of the shallowing MLD related to the warm “Blob. The salinity anomaly in the warm “Blob region resulted from a combination of both local and nonlocal effects. The freshened water at the surface played a local role in the MLD anomaly. Interestingly, the MLD anomaly was more dependent on the local subsurface salinity anomaly in the 100-150 m depth range in the NEP. The salinity anomaly in the 50-100 m depth range may be linked to the anomaly in the 100-150 m depth range by vertical advection or mixing. The salinity anomaly in the 100-150 m depth range resulted from the eastward transportation of a subducted water mass that was freshened west of the dateline, which played a nonlocal role. The results suggest that the early salinity anomaly in the NEP related to the warm “Blob may be a precursor signal of interannual and interdecadal variabilities.