| 夏季东亚地区AOD与地面太阳辐射变化的联系及季风环流异常:季节趋势影响 |
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| 引用本文： | 孙一,管兆勇,马奋华,夏阳.夏季东亚地区AOD与地面太阳辐射变化的联系及季风环流异常:季节趋势影响[J].大气科学学报,2015,38(2):165-174. |
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| 作者姓名： | 孙一 管兆勇 马奋华 夏阳 |
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| 作者单位： | 南京信息工程大学气象灾害预报预警与评估协同创新中心;气象灾害教育部重点实验室(南京信息工程大学) |
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| 基金项目： | 国家重点基础研究发展计划(973计划)项目(2011CB403406);江苏高校优势学科建设工程资助项目(PAPD) |
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| 摘 要： | 利用2000—2013年MODIS-Terra卫星产品提供的气溶胶光学厚度(aerosol optical depth,AOD)资料及NCEP/NCAR再分析资料集,使用奇异值分解(singular value decomposition,SVD)方法,分析了夏季东亚地区AOD与到达地面太阳辐射(downward solar radiation flux,DSRF)相联系的主要模态,并分析了其与夏季风变化的关系。夏季多年平均的AOD分布显示,在东亚地区存在两个AOD大值区(0.9),分别位于山东、河南、河北交界处附近以及苏中部分地区。而在福建、台湾及其附近洋面上,夏季AOD的值小于0.4。地面太阳辐射总体上呈现出由南往北递增的分布。比较发现,AOD与地面太阳辐射的气候分布较为相似。在保留季节趋势的情况下,运用SVD方法对两者进行分解,结果表明东亚地区AOD与地面太阳辐射表现出较好的正相关关系。由于相对于年际变化而言,季节趋势是更为主要的部分,因而这种同相关系可归因于季风活动的季节性进程。利用SVD1左场时间系数进行相关分析发现:6月(2013年除外),当中国东部气溶胶AOD大而地面太阳辐射亦大时,在中国东南部以及日本岛南部地区,由于气流辐合增强和存在较强的上升运动,降水偏多,而由于副高位置偏南,使得中国中东部偏北地区水汽供应偏弱,降水偏少。由于地面净太阳辐射增强,华北部分地区异常增暖。8月,大陆上空AOD为负(时间系数为负),地面太阳辐射减少,北方降水增多而南方降水减少,华北地区有一小范围的异常降温。上述结果表明北方气溶胶明显偏少时,云量增加,降水将增多,且辐射明显减弱;说明夏季风的季节进程对气溶胶、到达地面的太阳辐射变化等具有重要影响。
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| 关 键 词： | 气溶胶光学厚度 地面太阳辐射 夏季风 季节趋势 东亚地区 |
| 收稿时间： | 2014/10/11 0:00:00 |
| 修稿时间： | 2014/12/23 0:00:00 |
Linkage between AOD and surface solar radiation variability in association with East Asian summer monsoon circulation changes:Role of seasonal trends |
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| SUN Yi,GUAN Zhao-yong,MA Fen-hua and XIA Yang.Linkage between AOD and surface solar radiation variability in association with East Asian summer monsoon circulation changes:Role of seasonal trends[J].大气科学学报,2015,38(2):165-174. |
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| Authors: | SUN Yi GUAN Zhao-yong MA Fen-hua and XIA Yang |
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| Institution: | SUN Yi;GUAN Zhao-yong;MA Fen-hua;XIA Yang;Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters,NUIST;Key Laboratory of Meteorological Disaster(NUIST),Ministry of Education; |
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| Abstract: | Based on aerosol optical depth(AOD) data derived from MODIS sensors onboard the Terra satellite and NCEP/NCAR reanalysis data set from 2000 to 2013,the principal modes,which show the linkage between AOD and near surface downward solar radiation flux(DSRF) in East Asia in summer,have been explored with the singular value decomposition(SVD) method.The principal mode of AOD is further examined in association with East Asian summer monsoon.The distribution of summer AOD averaged from 2000 to 2013 shows that there are two high value regions(>0.9) in East Asia.One is in the conjunction part of Shandong,Henan,and Hebei provinces,and another is in central part of Jiangsu province.However,the values in Fujian,Taiwan provinces and their nearby ocean surface are less than 0.4.The DSRF increases from south to north,just like the AOD distribution.By using SVD method,a positive correlation between AOD and DSRF has been found under the influence of seasonal trends.By calculating the variance contributions,this paper confirms that the seasonal trends are more important than interannual variability in determining the in phase variations of AOD and DSRF.Left time coefficients of the leading SVD mode(SVD1) have been used to conduct correlation analysis.Results suggest that,in June(except 2013),when both AOD and DSRF values are high in eastern China,the convergence and ascending motion will be stronger than normal from the southeast China to the south of Japan.As a result,summer precipitation will increase.This is due to a fact that the location of the western Pacific subtropical high in June extends southward,resulting in less precipitation in northern parts of eastern China eventually.An anomalous warmer area appears in North China due to the more net surface solar radiation flux.In August,when AOD anomalies are negative over the land,DSRF is also less than normal.August precipitation will be less(more) than normal in the south(north) of China,along with an anomalous cold area in North China.These changes imply that when the aerosols are less than normal in the northern part of East Asia,the total cloud amount is more than normal,and rain will increase,resulting in the decrease of DSRF there.All of these results indicate that the seasonal evolution of East Asian summer monsoon plays an important role in regulating the variabilities of AOD and DSRF. |
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| Keywords: | aerosol optical depth(AOD) surface solar radiation summer monsoon seasonal trend East Asia |
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