Barrier layer in the indian ocean in a 200 year simulation of the Sintex-Frontier, CGCM (and other additional results)
Sebastien MassonFrontier Research System for Global Change.
Kanagawa 236-0001 JAPAN.
Tuesday, May 4, 11:00 CERFACS Conference Room
Abstract
The CGCM SINTEX-Frontier, originally developed in Europe has been implemented on the Earth Simulator. This model is based on OPA8.2 (ORCA2), ECHAM4.6 (T106L19) and OASIS 2.4.1. This seminar will present some of the results based on 200-year long experiments.
We will start with a short presentation of the model climatology. Next we will focus on the barrier layer (BL) in the Indian Ocean. In agreement with the observations, a thick BL (more than 20m) is observed (1) in the northern part of the Bay of Bengal from July to March with a maximum extent in January-February, (2) in the south-eastern Arabian Sea in January-February and (3) offshore of Sumatra in December-January. In agreement with Masson et al. [2002], off Sumatra, the BL variability is controlled by the Wyrtki jet intraseasonal and interannual variability. The formation mechanisms explored in previous studies are found again in the coupled model. Regarding to the potential impact of the BL on the climate, we found, in agreement with recent study of Durand et al. [2004], that in the south-eastern Arabian Sea the maximum of BL thickness lead SST maximum by about 1 month suggesting a significant impact of BL though the trapping of heat bellow the mixed layer. From December to February vertical inversion of temperature of more than 2 degrees are located in the northern part of the Bay. Regarding the interannual variability, the coupled model shows similar results in comparison with study of Masson et al. [2004] suggesting the positive impact of equatorial shallow salinity stratification on the IOD amplitude.
At the end of the talk, we will briefly present others results: (1) improvement of model SST and variability in the Pacific by taking into account the relative velocity of the ocean surface regarding to the atmosphere and (2) performance of seasonal forecasts during the last 20 years.
Cerfacs' Conferences 2004-2005 Home Page
