北极夏季无海冰状态时的东亚气候变化数值模拟研究

Simulation of the East Asian Summer Climate Change in the "Free Arctic" Condition

利用CMIP3模式在IPCC SRES A1B情景下对未来气候的预测结果,得到北极夏季无海冰的一种情况,即"free Arctic"。利用相应的海温场和CO2含量驱动全球大气环流模式,模拟北极夏季无海冰时的东亚气候。试验结果表明,夏季北极无海冰时,全球表面气温有不同程度的明显升高,高纬地区升温幅度大于低纬地区,同纬度地区陆地大于海洋。海平面气压场表现为陆地上一致性的降低以及副热带海洋和南极洲边缘部分海域的升高。此外,东亚夏季风环流明显增强,季风区降水明显增多。

By using the CMIP3 models＇projections under the IPCC SRES A1B scenario, a possible future Arctic condition—the ＂free Arctic＂ condition is generated. The corresponding monthly sea surface temperature and the set of CO2 abundances are used to drive the IAP9L-AGCM model for the purpose of analyzing East Asian climate change in the ＂free Arctic＂ condition. The experiment show that in boreal summer （JJA）, the global surface air temperature in the ＂free Arctic＂ condition will increase to different extents, with increments greater at high latitudes than at low latitudes and over lands than over oceans at the same latitudes. The sea level pressure will decrease over lands, but increase over the subtropical oceans and parts of the oceans around the Antarctic. In addition, the East Asian summer monsoon will enhance and the summer monsoon rainfall over eastern China will increase correspondingly.