Modeling the Tropical Pacific Ocean Using a Regional Coupled Climate Model

• Published in: Advances in atmospheric sciences Vol. 23; no. 4; pp. 625 - 638
• Main Author: 符伟伟 周广庆 王会军
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Nature B.V 01.07.2006; Graduate School of the Chinese Academy of Sciences, Beijing 100039%Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029; Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029
• Subjects: Atmosphere; Atmospheres; Atmospheric physics; Atmospheric sciences; Atmospherics; Circulation; Climate; Climate models; Cold regions; Computer based modeling; Computer simulation; Horizontal; Marine; Mathematical models; Oceans; Permissible error; Studies; 分辨率; 区域气候模型; 太平洋; 海洋热带气象; 耦合模型; coupled model; statistical correction; high-resolution; ENSO
• ISSN: 0256-1530; 1861-9533
• DOI: 10.1007/s00376-006-0625-x

A high-resolution tropical Pacific general circulation model （GCM） coupled to a global atmospheric GCM is described in this paper. The atmosphere component is the 5°× 4° global general circulation model of the Institute of Atmospheric Physics （IAP） with 9 levels in the vertical direction. The ocean component with a horizontal resolution of 0.5°, is based on a low-resolution model （2° × 1° in longitude-latitude）. Simulations of the ocean component are first compared with its previous version. Results show that the enhanced ocean horizontal resolution allows an improved ocean state to be simulated; this involves （1） an apparent decrease in errors in the tropical Pacific cold tongue region, which exists in many ocean models, （2） more realistic large-scale flows, and （3） an improved ability to simulate the interannual variability and a reduced root mean square error （RMSE） in a long time integration. In coupling these component models, a monthly ＂linear-regression＂ method is employed to correct the model＇s exchanged flux between the sea and the atmosphere. A 100-year integration conducted with the coupled GCM （CGCM） shows the effectiveness of such a method in reducing climate drift. Results from years 70 to 100 are described. The model produces a reasonably realistic annual cycle of equatorial SST. The large SSTA is confined to the eastern equatorial Pacific with little propagation. Irregular warm and cold events alternate with a broad spectrum of periods between 24 and 50 months, which is very realistic. But the simulated variability is weaker than the observed and is also asymmetric in the sense of the amplitude of the warm and cold events.