Fast and Slow Responses of the North Pacific Mode Water and Subtropical Countercurrent to Global Warming  

作　　者：XU Lixiao XIE Shang-Ping LIU Qinyu 

机构地区：[1]Physical Oceanography Laboratory and Key Laboratory of Ocean-Atmosphere Interaction and Climate in Universities of Shandong,Ocean University of China [2]Scripps Institution of Oceanography,University of California at San Diego,La Jolla,CA 92093-0230,USA [3]International Pacific Research Center and Department of Meteorology,University of Hawaii,Honolulu,HI 96822,USA

出　　处：《Journal of Ocean University of China》2013年第2期216-221,共6页中国海洋大学学报（英文版）

基　　金：supported by the National Basic Research Program of China(2012CB955602);National Key Program for Developing Basic Science(2010CB428904);Natural Science Foundation of China(41176006 and 40921004)

摘　　要：Six coupled general circulation models from the Coupled Model Intercomparison Project Phase 5 (CMIP5) are em-ployed for examining the full evolution of the North Pacific mode water and Subtropical Countercurrent (STCC) under global warming over 400 years following the Representative Concentration Pathways (RCP) 4.5. The mode water and STCC first show a sharp weakening trend when the radiative forcing increases, but then reverse to a slow strengthening trend of smaller magnitude after the radiative forcing is stablized. As the radiative forcing increases during the 21st century, the ocean warming is surface-intensified and decreases with depth, strengthening the upper ocean's stratification and becoming unfavorable for the mode water formation. Moving southward in the subtropical gyre, the shrinking mode water decelerates the STCC to the south. After the radiative forcing is stabilized in the 2070s, the subsequent warming is greater at the subsurface than at the sea surface, destabilizing the upper ocean and becoming favorable for the mode water formation. As a result, the mode water and STCC recover gradually after the radiative forc-ing is stabilized.Six coupled general circulation models from the Coupled Model Intercomparison Project Phase 5 （CMIP5） are em- ployed for examining the full evolution of the North Pacific mode water and Subtropical Countercurrent （STCC） under global warming over 400 years following the Representative Concentration Pathways （RCP） 4.5. The mode water and STCC first show a sharp weakening trend when the radiative forcing increases, but then reverse to a slow strengthening trend of smaller magnitude after the radiative forcing is stablized. As the radiative forcing increases during the 21st century, the ocean warming is surface-intensified and decreases with depth, strengthening the upper ocean＇s stratification and becoming unfavorable for the mode water formation. Moving southward in the subtropical gyre, the shrinking mode water decelerates the STCC to the south. After the radiative forcing is stabilized in the 2070s, the subsequent warming is greater at the subsurface than at the sea surface, destabilizing the upper ocean and becoming favorable for the mode water formation. As a result, the mode water and STCC recover gradually after the radiative forcing is stabilized.

关 键 词：mode water STCC fast and slow response CMIP5 radiative forcing 

分 类 号：P461.2[天文地球—大气科学及气象学]