亚洲热带气候态夏季风涌传播特征及其对中国降水的影响

基于1979—2020年逐日的NOAA向外长波辐射资料、NCEP/NCAR再分析风场资料,以及全球CMAP再分析降水资料,探讨了气候态亚洲热带夏季风涌的传播过程及与我国夏季相应的降水联系。分析结果表明,主汛期亚洲热带气候态夏季风季节内振荡(CISO)活动是亚洲夏季风活动的主要特征,随时间北传的亚洲热带夏季风CISO称为亚洲热带夏季风涌,主要有南亚夏季风涌和南海夏季风涌。亚洲热带夏季风涌的传播可分为四个阶段。在亚洲热带夏季风涌的发展阶段,印度洋区域低频气旋与对流活跃,孟加拉湾和南海热带区域被低频东风控制,我国大部分地区无降水发生,降水中心位于两广地区。当进入亚洲热带夏季风涌活跃阶段,孟加拉湾和南海热带地区低频气旋和对流活跃,东亚低频“PJ”波列显著,我国降水中心北移到长江以南的附近区域。亚洲热带夏季风涌减弱阶段,孟加拉湾与南海低频气旋消亡,对流减弱,低频西风加强,日本南部附近为低频反气旋控制,我国长江中下游低频南风活跃,降水中心也北移到长江中下游地区,而华南地区已基本无降水,此阶段的大气低频环流场与亚洲热带夏季风涌发展阶段基本相反。进入亚洲热带夏季风涌间歇阶段时,孟加拉湾和南海热带地区低...     

亚洲-太平洋涛动与中国南方地区1月降水异常的关系

利用NCEP、ERA-40再分析资料和中国160个观测站逐月降水资料,分析了同期和前期亚洲-太平洋涛动(APO)与中国南方地区冬季1月降水异常的关系,并讨论了相应的联系机制.研究发现,1月亚洲-太平洋涛动指数能够很好地反映同期中国南方地区降水异常.亚洲-太平洋涛动的异常变化可能影响对流层低层位势高度场,进而通过影响亚洲中、低纬度地区的对流层低层风场与中国南方地区降水紧密联系.当亚洲-太平洋涛动指数偏低(高)时,对应在东亚南部及其邻近海域对流层低层位势高度偏高(低),东太平洋位势高度偏低(高).相应地,南海以及华南沿海地区为异常西南(东北)风控制,且该异常风向北逐渐减弱,进而在中国南方地区辐合(辐散),这既有(不)利于暖湿气流向中国南方地区输送,同时也造成了该地区的水汽辐合(辐散),从而导致降水偏多(少).亚洲-太平洋涛动具有很好的持续性,上一年10月亚洲-太平洋涛动异常可一直持续至当年1月,表现出连续的显着相关特征.因此,其与中国南方地区1月降水异常也具有显着联系,可以作为指示1月中国南方地区降水多寡的一个前兆因子.     

Interannual Variability of Autumn Precipitation over South China and its Relation to Atmospheric Circulation and SST Anomalies

The interannual variability of autumn precipitation over South China and its relationship with atmospheric circulation and SST anomalies are examined using the autumn precipitation data of 160 stations in China and the NCEP-NCAR reanalysis dataset from 1951 to 2004. Results indicate a strong interannual variability of autumn precipitation over South China and its positive correlation with the autumn western Pacific subtropical high （WPSH）. In the flood years, the WPSH ridge line lies over the south of South China and the strengthened ridge over North Asia triggers cold air to move southward. Furthermore, there exists a significantly anomalous updraft and cyclone with the northward stream strengthened at 850 hPa and a positive anomaly center of meridional moisture transport strengthening the northward warm and humid water transport over South China. These display the reverse feature in drought years. The autumn precipitation interannual variability over South China correlates positively with SST in the western Pacific and North Pacific, whereas a negative correlation occurs in the South Indian Ocean in July. The time of the strongest lag-correlation coefficients between SST and autumn precipitation over South China is about two months, implying that the SST of the three ocean areas in July might be one of the predictors for autumn precipitation interannual variability over South China. Discussion about the linkage among July SSTs in the western Pacific, the autumn WPSH and autumn precipitation over South China suggests that SST anomalies might contribute to autumn precipitation through its close relation to the autumn WPSH.     

南方涛动年际变化与夏季亚澳季风环流及海洋性大陆区域气候异常的联系

利用美国NOAA卫星观测的SOI(Southern Oscillation Index,南方涛动指数)资料以及NCEP/NCAR、CMAP月平均资料,采用相关分析等方法,研究了南方涛动年际变化与夏季亚澳季风环流及海洋性大陆区域气候异常的联系。结果表明:南方涛动具有显著的年际变化特征,这种年际变化对夏季亚澳季风区及海洋性大陆区域的环流、降水及温度异常有重要影响。当SOI正位相时,赤道以南的澳大利亚东部地区以及西北太平洋海域高层为气旋,低层为反气旋,赤道地区的东部太平洋低层为辐散中心,高层为辐合中心,有利于下沉运动维持;加里曼丹岛附近低层辐合,高层辐散,有利于上升运动维持;海洋性大陆地区降水为显著的正异常,东亚地区降水存在较弱的正异常;海洋性大陆地区以及我国青藏高原到东海一带温度为正异常,孟加拉湾及印度半岛区域温度为负异常。     

南方暴雨成灾北方强对流频发——2008年8月

2008年8月,正值我国举办奥运会,期间我国出现了不少强天气过程,南方暴雨洪涝和北方强对流频发.本月,全国平均月降水量比常年同期偏多;安徽月降水量为1951年以来历史同期第2多,湖北、贵州为历史同期第3多.     

南方持续低温阴雨雪 部分地区遭严重冻害(2005年2月)

2月份，全国大部地区降水量较常年同期偏多，南方部分地区出现持续低温阴雨雪寡照天气；江南及福建等局部出现暴雨及山体滑坡等灾害；滇、新等地局部发生雪灾；华南中南部、云南南部持续少雨雪，旱情持续或发展。月平均气温，全国大部地区较常年同期偏低，湘、鄂、黔等地的部分地区遭受严重冰冻灾害。     

ANALYSIS OF CHANGING FLOOD CHARACTERISTICS IN SOUTH CHINA DURING THE RECENT 50 YEARS

1 INTRODUCTION The trend of drought and flood variation has been a wide concern among scientists in the background of climate warming in the late 20th century[1]. Both of them are serious natural disasters that regularly take place in China. Relevant studies have shown that there are roughly the same number of stations in China showing increasing rainfall as those showing decreasing rainfall over the past 50 years. There are no obvious trends of variation of annual precipitation averaged…     

第21届欧洲光伏太阳能大会及2006长城世界可再生能源论坛介绍以及对气象部门的启示

今年9月份、10月份，第21届欧洲光伏太阳能大会及展览会（EU PVSEC）、长城世界可再生能源论坛（GWREF）先后召开，这两次国际会议规模都比较大，在清洁能源研发和应用领域，都具有较强的国际影响力。新能源的发展日益受到重视，气象部门在新能源的资源评估、选址、监测、预测，后期保障等领域都大有可为。本刊搜集、翻译、整理了两次会议的有关情况，介绍给广大气象工作者，期待能为读者带来一些启示。     

The Freezing Precipitation over the Middle-Lower Reaches of the Yangtze River during February-March 2009

In this paper, the authors analyze the quasistationary fronts, surface conditions, and atmospheric stratification processes associated with a freezing precipitation event over the middle-lower reaches of the Yangtze River, especially in the Dabie mountain during February-March 2009. The long duration of freezing precipitation was primarily caused by stationary and anomalous synoptic weather patterns, such as a blocking high pressure in the northern branch and a trough in the southern branch of the westerlies, which resulted in the encounter cold air from northern China and warm moisture from the south. The east-west-oriented, quasi-stationary front （or shear line） found in central China was mostly responsible for producing the precipitation. The warm layer and nearsurface frozen layer were located in the lower troposphere along the front zone. Although the warm layer （〉 0℃） existed along the whole front, a surface temperature less than 0℃ appeared only over the lower-middle reaches of the Yangtze River, especially in the Dabie mountain. Therefore, the surface temperature was the main influencing factor, as the freezing precipitation only happened over the Dabie mountain.