General Circulation Response To The Warming Of Eastern Marginal Seas Of China

Under the background of global warming, ocean temperature increases too. Inthe past30years, sea surface temperature in the western boundary current areas risessignificantly, especially the Kuroshio through the coast of Eastern china. TheKuroshio plays an important role in the transporting heat, momentum, heat, watervapor flux between the mid-latitude and low-latitude and it realizes the energyexchange between the middle and low latitudes.So, its thermal status changes musthave important effect on the air over and even all the global atmospheric circulation.This paper focuses on the effect of SST anomaly to general circulation as a keyscientific issue, applying the Weather Research and Forecasting Model to simulateSST anomaly over the Eastern Marginal Seas of China, to reveal its effect.In order to exclude other factors’ disturbance to the general circulation, in theexperiment design,control run and sensitivity experiment use the same model settingand parameterization scheme, the same integral time, and the only difference is theboundary condition-SST. And in order to eliminate the atmospheric noise,the twogroups of experiments also contain50-ensembles, finally let the average result to bege final result. In addition, in order to make the comparison easily, choose the winterand summer season. Each group integrals for3months,and average the last2monthsto be the final results. And then use the average of50-ensembles to get theatmospheric information.Through comparative analysis of wind filed,temperature field, geopotential fieldand precipitation in the winter and summer response to the SST anomaly,it finds3points: firstly, from the season, the atmosphere response to the SST anomaly isstronger in summer than in winter, and the response in winter is mainly local;from thevertical suspect, the signal in summer can reach to250hPa, but for winter only at lowlevel, in winter the effect of SST anomaly is shallow; from sea and land, China inlandhardly has any response, the strong response signals are all over the sea. When discussall the variables,no matter the winter and summer, under the SST anomaly forcing,there is always cyclone circulation occurring in local or the downstream, theconvergence occurs at the low layer,and there is upward motion, when the watervapor abundance,it is prone to precipitation, therefore in the east of warming area there is much precipitation.According to the Dyne compensation principle,low levelconvergence and divergence at high level. That is as the “ridge” in geopotential hightfield-winter(700hPa),summer(250hPa),low level is trough anomaly,then theresponse is baroclinicity. The precipitation anomalous mainly distributes in the east ofthe warming area,this is related to the winter and summer monsoon and upwardmovement.In summary, the effect of warming SST can not be ignored,it is so important thatthe monsoon in winter (summer) will be stronger（abate） as the warming SST,thatwill directly lead to the northern cold air southward, has significant effect on the airtemperature of China inland, further effects the precipitation.