서로 다른 격자 해상도를 가지는 전지구 해양-해빙 모델에서 모의된 해양순환의 비교

Abstract

Global oceanic features are simulated and compared based on the coupled global ocean-sea ice models (GFDL MOM4p1-SIS). Horizontal grid resolutions of the two models are nominally 1 degree (GCM_1) and 0.5 degree (GCM_0.5), and more refined grid spacings are taken in meridional direction in the equatorial region, respectively. Both models employ the common atmospheric data (radiation, wind, air temperature, specific humidity, sea level pressure, precipitation and land runoff) from the CORE-II normal year forcing dataset and adopt the same numerical schemes in tracer and momentum advection and diffusion with the same coefficients of eddy viscosity and eddy diffusivity between them.The time scale for reaching a quasi-steady state in the global mean temperature, salinity, and sea surface height in GCM_1 are shown to be about 700 - 800 years which is much longer than in GCM_0.5 (about 400 years). After 400 years of integration GCM_1 shows warm biases compared to the observation in the sea surface temperature(SST) at the western Equatorial Pacific, Asian Marginal Seas, North Pacific subtropical region, west off South America and Africa, and Southern Oceans. It also shows cold biases at those areas such as in the central part of the subtropical gyre in the North Pacific and most of the North Atlantic and Greenland Sea. Compared to GCM_1 GCM_0.5 reveals some improved SST patterns showing much reduced warm- and cold-biased rrid spacings are taken in meridional direction in the equatorial region, respectively. Both models employ the common atmospheric data (radiation, wind, air temperature, specific humidity, sea level pressure, precipitation and land runoff) from the CORE-II normal year forcing dataset and adopt the same numerical schemes in tracer and momentum advection and diffusion with the same coefficients of eddy viscosity and eddy diffusivity between them.The time scale for reaching a quasi-steady state in the global mean temperature, salinity, and sea surface height in GCM_1 are shown to be about 700 - 800 years which is much longer than in GCM_0.5 (about 400 years). After 400 years of integration GCM_1 shows warm biases compared to the observation in the sea surface temperature(SST) at the western Equatorial Pacific, Asian Marginal Seas, North Pacific subtropical region, west off South America and Africa, and Southern Oceans. It also shows cold biases at those areas such as in the central part of the subtropical gyre in the North Pacific and most of the North Atlantic and Greenland Sea. Compared to GCM_1 GCM_0.5 reveals some improved SST patterns showing much reduced warm- and cold-biased r