Preliminary results of a regional air-sea coupled model over East Asia

Abstract

We have established a regional air-sea coupled model over East Asia and conducted a 20-year integration to evaluate its performance in reproducing the present climate. The coupled model consists of RegCM3 and HYCOM controlled by the OASIS3 coupler with resuolution of 60 km for the atmosphere and 33 km for the ocean, respectively. Unlike some other regional air-sea coupled models, a one-way nesting method is employed in the oceanic component and a heat flux adjustment for solar radiation is used to remove an about 2°C cold bias in SST. The primary analysis for this 20-year integration shows that the coupled model successfully reproduces the main features of the circulations over East Asia, both in the atmosphere and the ocean, including climatology, seasonal and interannual variations. Improvements are seen in the coupled model compared to the uncoupled one, especially in the simulation of precipitation, the most important element of the East Asian monsoon, although there are still obvious discrepancies that come mainly from the model components themselves. Further analyses show that the rainfall simulation benefits from the enhancements of the Northwest Pacific Subtropical High in summer, which leads to the improvement of the moisture flux simulation at the middle-lower atmospheric circulation. The results indicate that the regional air-sea coupled model is more suitable for the East Asia monsoon simulation. regional, coupled model, air sea, East Asia, OASIS3 coupler Citation:Li T, Zhou G Q. Preliminary results of a regional air-sea coupled model over East Asia.

Effects of climate change on heating and cooling degree days and potential energy demand in the household sector of China

“…the East Asian monsoon) (e.g. Gao et al 2001, Zhou & Yu 2006, Ju et al 2007, Li & Zhou 2010. Therefore, in this study, we present an analysis of the future changes in HDD and CDD over China based on climate projections conducted with a high-resolution RCM under 2 representative concentration pathways (RCPs) (the high-level RCP8.5 and mid-level RCP4.5; Moss et al 2010).…”

Evaluating the impacts of cumulus, land surface and ocean surface schemes on summertime rainfall simulations over East-to-southeast Asia and the western north Pacific by RegCM4

“…The simulated spatial distribution, intensity and interannual variation of the precipitation, latent heat flux, position of the subtropical high and tropical cyclone genesis patterns from these numerical experiments were analyzed. Gao et al 2001;Ju et al 2007;Li and Zhou 2010;Gao et al 2011;Au-Yeung and Chan 2012;Gao et al 2013;Huang et al 2013;Huang and Chan 2014). Oftentimes, alternative parameterizations can exist for the same physical process in RegCM4; uncertainties and discrepancies of rainfall simulation can be introduced by alternating different physical schemes.…”

A Role of the Yellow and East China Seas in the Development of Extratropical Cyclones in Winter

“…The suggestion is that the Yellow and East China Seas are interactive, rather than active, in East Asian weather. Therefore, it is likely that an air-sea coupled model established for marginal seas (e.g., Fang et al 2010;Li and Zhou 2010) is required to uncover this highly complex interactive process in East Asia. Otherwise, quantitative assessment, such as that regarding the 6.2% period of potentially disastrous weather (section 4b), will remain inconclusive.…”