관측과 CCSM4의 북태평양중층수 분포 비교

Abstract

The North Pacific Intermediate Water (NPIW) simulated by the Community Climate System Model version 4 (CCSM4) is compared to observations with respect to its overall property distributions. Despite the CCSM4 shows improvement such as reduced temperature and salinity biases at the density of the NPIW compared to the CCSM3, the model bias on water mass properties still exists. Salinity simulated in CCSM4 is higher than observation in the western subtropical region, south of the Kuroshio Extension (KE), while it is lower in the polar region. On the contrary, pCFC is simulated lower (higher) than observation in the south (north) of the KE. This implies that CCSM4 does not properly simulate the transfer of water at the density of the NPIW. Lower pCFC as well as higher salinity than observation in the western subtropical region implies that the short pathway of the NPIW toward the subtropical region is not represented in CCSM4.ed temperature and salinity biases at the density of the NPIW compared to the CCSM3, the model bias on water mass properties still exists. Salinity simulated in CCSM4 is higher than observation in the western subtropical region, south of the Kuroshio Extension (KE), while it is lower in the polar region. On the contrary, pCFC is simulated lower (higher) than observation in the south (north) of the KE. This implies that CCSM4 does not properly simulate the transfer of water at the density of the NPIW. Lower pCFC as well as higher salinity than observation in the western subtropical region implies that the short pathway of the NPIW toward the subtropical region is not represented in CCSM4.