摘要
The response of the North Pacific Subtropical Mode Water and Subtropical Countercurrent (STCC) to changes in greenhouse gas (GHG) and aerosol is investigated based on the 20th-century historical and single-forcing simulations with the Geo-physical Fluid Dynamics Laboratory Climate Model version 3 (GFDL CM3). The aerosol effect causes sea surface temperature (SST) to decrease in the mid-latitude North Pacific, especially in the Kuroshio Extension region, during the past five decades (1950-2005), and this cooling effect exceeds the warming effect by the GHG increase. The STCC response to the GHG and aerosol forcing are opposite. In the GHG (aerosol) forcing run, the STCC decelerates (accelerates) due to the decreased (increased) mode waters in the North Pacific, resulting from a weaker (stronger) front in the mixed layer depth and decreased (increased) subduction in the mode water formation region. The aerosol effect on the SST, mode waters and STCC more than offsets the GHG effect. The response of SST in a zonal band around 40?N and the STCC to the combined forcing in the historical simulation is similar to the response to the aerosol forcing.
The response of the North Pacific Subtropical Mode Water and Subtropical Countercurrent （STCC） to changes in greenhouse gas （GHG） and aerosol is investigated based on the 20th-century historical and single-forcing simulations with the Geo- physical Fluid Dynamics Laboratory Climate Model version 3 （GFDL CM3）. The aerosol effect causes sea surface temperature （SST） to decrease in the mid-latitude North Pacific, especially in the Kuroshio Extension region, during the past five decades （1950-2005）, and this cooling effect exceeds the warming effect by the GHG increase. The STCC response to the GHG and aerosol forcing are opposite. In the GHG （aerosol） forcing run, the STCC decelerates （accelerates） due to the decreased （increased） mode waters in the North Pacific, resulting from a weaker （stronger） front in the mixed layer depth and decreased （increased） subduction in the mode water formation region. The aerosol effect on the SST, mode waters and STCC more than offsets the GHG effect. The response of SST in a zonal band around 40°N and the STCC to the combined forcing in the historical simulation is similar to the response to the aerosol forcing.
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)
