BCC_CSM1.1(m)模式对于夏季亚洲-太平洋涛动的模拟

亚洲-太平洋涛动是北半球夏季亚洲大陆和北太平洋副热带地区对流层中高层扰动温度场上大尺度的东西反相的遥相关现象，其异常变化与亚洲-太平洋地区夏季风气候有着密切的联系.基于欧洲中心的ERA-40再分析资料和国家气候中心BCC_CSM1.1（m）气候系统模式多年的数值模拟结果，本文主要评估了BCC_CSM1.1（m）模式对于夏季亚洲-太平洋涛动的空间分布、指数的时间演变及与其变化所对应的亚洲地区夏季环流异常等方面的模拟能力，结果表明：BCC_CSM1.1（m）模式能够较好地模拟出北半球夏季对流层中高层扰动温度在亚-太地区中纬度存在的西高东低"跷跷板"现象；模式能够模拟出夏季亚洲-太平洋涛动指数的年际变率，但是不能模拟出该指数在20世纪60-70年代明显下降的年代际趋势；模式还能较好地模拟出亚洲-太平洋涛动高低指数年亚洲-太平洋地区夏季环流的异常：指数偏高年份，南亚高压增强，高空西风急流带和热带东风急流均加强，索马里越赤道气流增强，南亚热带季风和东亚副热带季风均增强，东亚季风低压槽加强，西北太平洋副热带高压增强，南亚和东亚北部降水增加，菲律宾地区、中国长江流域-朝鲜半岛-日本一带地区降水减少，反之亦然.

Simulation of the Asian-Pacific Oscillation using the BCC_CSM1.1(m) model

The Asian-Pacific Oscillation (APO) is a zonal teleconnection pattern of the eddy temperature field in the middle and high troposphere over the extra-tropical Asian-Pacific region. Its anomalous change is closely related to the Asian and Pacific summer monsoon. Based on the monthly European Center for Medium-Range Weather Forecast reanalysis data ERA-40 and numerical simulation of the BCC_CSM1.1(m) model in Beijing Climate Center,this paper evaluates the ability of BCC_CSM1.1(m) model in simulating the summer APO spatial distribution, evolution of APO index and the climate differences between the higher and lower APO index years. Results show that BCC_CSM1.1(m) can well simulate the out-of-phase relationship in the upper-tropospheric eddy temperature between Asia and North Pacific mid-latitudes in Northern Hemisphere summer, and the model is also able to successfully simulate the interannual variability of APO index, but fails to catch the significantly decreasing trend in 1960s-1970s.Furthermore, BCC_CSM1.1(m) can successfully reproduce the Asian and Pacific summer monsoon climate changes corresponding to the APO index variation. With higher APO index conditions, the summer South Asian high and the North Pacific trough are stronger,while the westerly jet stream over Asia and the easterly jet stream over South Asia both strengthen in the upper troposphere. Meanwhile, the Asian low and the North Pacific subtropical high are stronger in the lower troposphere. The anomalous southerlies prevail at 40°E-50°E longitudes and the mid-latitudes of East Asia, and the anomalous westerlies prevail over South Asia. Summer rainfall increases in South Asia and northern of East Asia, while it decreases from the Yangtze River Basin to Japan and the Philippines region, and vice versa.