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| 1—3月北极涛动对北半球热带太平洋和大西洋对流活动的可能影响 | |
| 引用本文： | 胡淼,龚道溢,王璐,周天军,张自银.1—3月北极涛动对北半球热带太平洋和大西洋对流活动的可能影响[J].气象学报,2012,70(3):479-491. |
| 作者姓名： | 胡淼 龚道溢 王璐 周天军 张自银 |
| 作者单位： | 1. 北京师范大学,地表过程与资源生态国家重点实验室,北京,100875 2. 中国科学院,大气物理研究所,LASG,北京,100029;中国科学院研究生院,北京,100049 3. 中国科学院,大气物理研究所,LASG,北京,100029 |
| 基金项目： | 国家高技术研究发展计划(863计划)重点项目，国家科技支撑计划课题 |
| 摘 要： | 利用1979—2008年日分辨率的向外长波辐射资料以及NCEP再分析资料,去除ENSO影响后,分析了1—3月北极涛动对热带太平洋和热带大西洋对流活动及降水的可能影响。结果表明北极涛动偏强(弱)时,热带太平洋和大西洋对流活动显著偏强(弱)。北半球热带大洋冬季平均向外长波辐射与北极涛动指数的相关系数存在两个显著负相关区:一个位于中太平洋区,大致包括13°—20°N、160°E—170°W;另外一个位于热带大西洋,显著区覆盖的范围大体包括5°—20°N、15°—70°W。这些区域的降水量也表现出显著的正相关。向外长波辐射、强对流面积指数、强对流强度指数、平均降水量等指标与北极涛动指数的相关均以冬季同期最高,随时间滞后相关迅速减弱。与此对应的对流层低层大气环流也有显著变化,850hPa风场的变化表现为热带太平洋有异常的气旋性环流,气旋中心区与显著强对流和降水异常区一致。而热带大西洋有显著的经向环流辐合和风切变,与异常对流和降水区吻合。海洋模式的模拟结果表明,与北极涛动有关联的海温分布,很大程度上与大气强迫有关,说明热带1—3月降水和对流活动与海温的关联较弱。北极涛动与热带太平洋、大西洋对流和降水活动之间主要是通过大气环流的变动产生联系的。 |
| 关 键 词： | 北极涛动 对流活动 热带太平洋 热带大西洋 |
| 收稿时间： | 2010/6/28 0:00:00 |
| 修稿时间： | 2011/10/23 0:00:00 |
Possible influence of January March Arctic Oscillation on the convection of tropical North Pacific and North Atlantic |
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| HU Miao,GONG Daoyi,WANG Lu,ZHOU Tianjun and ZHANG Ziyin.Possible influence of January March Arctic Oscillation on the convection of tropical North Pacific and North Atlantic[J].Acta Meteorologica Sinica,2012,70(3):479-491. | |
| Authors: | HU Miao GONG Daoyi WANG Lu ZHOU Tianjun and ZHANG Ziyin |
| Institution: | 1. State Key Laboratory of Earth Surface Processes and Resource Ecology, Beijing Normal University, Beijing 100875, China 2. State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics (LASG), Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China 3. Graduate School of the Chinese Academy of Sciences, Beijing 100049, China |
| Abstract: | An analysis of detailed relationships between the January-February-March Arctic Oscillation and the convection in the tropical Pacific Ocean and the tropical Atlantic Ocean is presented based on the daily outgoing longwave radiation dataset and the monthly NCEP reanalysis datasets with the ENSO signals removed from all the datasets. The results indicate that a high (low) AO phase more likely accompanies with a stronger (weak) convection in the tropical Pacific Ocean and the tropical Atlantic Ocean. The correlations between the AO index and the tropical OLR in boreal winter show two pronounced negative correlation areas: one in the central Pacific Ocean, ranging between 13°-20°N, 160°E-170°W and the other in the tropical Atlantic Ocean, covering 5°-20°N, 15°-70°W. The prominent positive correlation is also demonstrated in the precipitation field. The time-lag correlation analyses indicate that the correlation of the AO index with the OLR, the strong convection area, the intensity index and the mean precipitation is the strongest in the concorrent winter and the correlation weakens rapidly with time. At the same time, the lower tropospheric atmosphere circulation anomalies corresponding to the JFM AO index change significantly in the two regions. During positive AO winter, there is an anomalous atmospheric cyclone in the tropical Pacific Ocean while there are a meridional circulation convergence and a horizontal wind shear in the tropical Atlantic Ocean at 850 hPa. And the AO-related SSTs, particularly in the central ocean regions, are well reproduced by the simulation experiments of the ocean model LICOM, suggesting that the observed AO-related SSTs are mainly the response to atmospheric circulation changes. Meanwhile, the connections of AO-related SSTs with convection and precipitation activities are relatively weak. The changes in the atmospheric circulation are probably the main linkage among the AO and convection and precipitation in the tropical Pacific and Atlantic Ocean for January to March. |
| Keywords: | Arctic Oscillation Convection activity Tropical Pacific Ocean Tropical Atlantic Ocean |
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