东亚地区气溶胶光学厚度与地面太阳辐射变化的联系及其与夏季风异常

发布时间：2018-01-10 15:28

本文关键词：东亚地区气溶胶光学厚度与地面太阳辐射变化的联系及其与夏季风异常　出处：《南京信息工程大学》2015年硕士论文　论文类型：学位论文

【摘要】：本文利用20002013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SVD方法研究了夏季东亚地区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。主要得到以下结论：(1)夏季,东亚地区AOD与DSRF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(除2013年外),当中国东部气溶胶AOD大而地面太阳辐射亦大时,在中国东南部地区以及日本岛南部,由于气流辐合增强和较强的上升运动,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,情况则相反。这些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。(2)在扣除季节趋势的情况下,运用SVD方法对AOD和DSRF进行分解,结果表明夏季,两者呈现较好的反相关关系,即我们通常所认识到的“阳伞效应”。AOD变化的20%可显著影响到达地表太阳辐射的10%左右。利用SVD1左场时间系数进行相关分析发现,当AOD在中国东部偏北地区显著增加和在华南沿海及南海地区减少时,中国东部南北方加热差异增大,而在南部地区则减小了海陆热力差异,这又有利于海陆气压差的减小,从而减弱了夏季风。减弱的夏季风有利于南海-西太平洋以及华北和东北云量偏少,降水显著偏少,但在中国东部的长江流域及江南,降水有增加的倾向。中国东部长江流域以南温度降低,中国东部偏北地区温度升高。(3)东亚地区AOD典型强(弱)年与夏季风的弱(强)年相对应。区域平均AOD的强、弱年AOD的异常分布既受气候平均的东亚季风环流影响,同时也受异常夏季风环流引起的气溶胶异常分布的影响。视源汇项的影响也非常重要,其与降水的湿清除作用存在联系。
[Abstract]:The aerosol optical depth provided by MODIS-Terra satellite products in 2000-2013 is used in this paper. Ado) data and NCEP/NCAR reanalysis data set. The SVD method is used to study AOD and downward solar radiation flux in East Asia in summer. The relationship between DSRF and summer monsoon variation is analyzed. The following conclusions are obtained: 1) Summer. The climate distribution of AOD and DSRF in East Asia is similar. The SVD method is used to decompose the AOD and DSRF under the condition of keeping the seasonal trend. The results show that there is a good positive correlation between AOD and surface solar radiation in East Asia, and the seasonal trend is more important than interannual variation. Therefore, this phase relationship can be attributed to the seasonal process of monsoon activity. The correlation analysis using SVD1 left field time coefficient shows that: June (except 2013). When the aerosol AOD is large and the surface solar radiation is high in eastern China, there is more precipitation in southeastern China and the southern part of Japan, due to the stronger convergence of air flow and the stronger upward movement. However, due to the southward position of the subtropical high, the water vapor supply is weak and the precipitation is low in the north-central part of China. Due to the enhancement of the surface net solar radiation, some parts of North China are abnormally warm. August. This indicates that the seasonal process of the summer monsoon has an important effect on aerosols, solar radiation to the ground, and so on. SVD method is used to decompose AOD and DSRF. The results show that there is a good inverse correlation between AOD and DSRF in summer. That is to say, 20% of the "parasol effect". 20% of the variation of AOD can significantly affect the solar radiation reaching the surface of the earth's surface about 10%. The correlation analysis of the time coefficient of SVD1 left field is carried out. When AOD increases significantly in the north-eastern part of China and decreases in the South China coastal and South China Sea, the heating difference between the south and north of China increases, while the thermal difference between the sea and the land decreases in the southern part of China. This, in turn, is beneficial to the decrease of the difference between sea and land pressure, which weakens the summer monsoon, which is beneficial to the decrease of clouds and precipitation in the South China Sea and the Western Pacific Ocean, as well as in North and Northeast China. However, precipitation tends to increase in the Yangtze River basin and south of the Yangtze River in eastern China, and the temperature in the south of the Yangtze River basin in eastern China is lower. The typical strong (weak) year of AOD in East Asia corresponds to the weak (strong) year of summer monsoon, and the regional average AOD is strong. The anomalous distribution of AOD in weak years is influenced not only by the average East Asian monsoon circulation, but also by the anomalous distribution of aerosol caused by the anomalous summer monsoon circulation. The apparent source and sink term is also very important. It is related to the wet removal of precipitation.
【学位授予单位】：南京信息工程大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X513;X16

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