大尺度形势对中尺度对流风暴影响的研究

通过对多次强对流过程的分析,归纳出大尺度天气形势对中尺度对流风暴发生发展影响的4个方面,提出了天气形势分型的基本原则,并介绍了北京、华东和闽南地区不同天气形势下强对流活动的特点。     

9216号热带风暴的初步分析

对9216号热带风暴在9月1日02时中心分裂的原因,作了初步探讨,认为东南低空急流使热带风暴倒槽区的气旋性环流加强,以及低涡的吸引合并,是产生新中心的原因。青岛产生大暴雨的条件,是充沛的水汽,强烈的上升运动和长波槽东移影响。     

1991 年江淮暴雨的定量预报检验

利用Threat Score方法，对1991年6月12—15日，6月29日—7月12日江淮持续暴雨的定量预报进行了检验。结果表明，对于大雨和暴雨预报，目前主观预报优于客观预报。数值预报在降雨定量预报的某些方面有了一定突破。     

长春台磁暴特征研究

依据长春地震台记录的磁暴资料,系统总结了第19、20、21三个太阳活动周磁暴特征,并对全球M_s≥7.8级地震的发生与太阳黑子活动、磁暴的关系进行了初步探讨。     

局地强风暴云团与中尺度锋面波动

本文分析了1982—1988年2—5月份的41例与中尺度锋面波动相关联的局地强风暴云团的活动和演变特征，给出了其强盛期天气系统配置模式及其在天气尺度云系演变中的表现型式，最后对其移动做了一般性讨论。     

台风影响期间珠江三角洲局地强风暴和大暴雨发生的环境条件

采用１９７６－１９８３年６－８月珠江三角洲地区受台风影响期间区内各站逐日的强风暴和降水资料以及广泛站的探空资料，用相关对比度分析方法，对台风环流中的珠江三角洲局地强风暴和大暴雨发生的环境条件进行统计诊断，得出台风影响珠江三角洲时这两种强天气发生的有利的环境条件，并发现二者在气压、风速、层结稳定度和中下层位势不稳定等方面显著不同。     

Aspiration and reality: flood policy, economic damages and the appraisal process

Research shows that flood damage potential has increased significantly in the last 15 years. At the same time, flood policy has shifted away from simplistic flood defence towards 'living with floods' and 'making space for water'. This paper explores the mis-match between the aspiration in policy ideals, the reality of rising potential economic damages and the inability of the flood risk appraisal process to match the aspiration with the reality. Unless investment appraisal procedures are changed, the increase in damages will undermine policy changes that seek a different pattern of flood risk management, away from economically dominated decision-criteria towards more sustainable objectives.     

The structure of the mid- and high-latitude ionosphere during the November 2004 storm event obtained from GPS observations

GPS data from the International GNSS Service (IGS) network were used to study the development of the severe geomagnetic storm of November 7–12, 2004, in the total electron content (TEC) on a global scale. The TEC maps were produced for analyzing the storm. For producing the maps over European and North American sectors, GPS measurements from more than 100 stations were used. The dense network of GPS stations provided TEC measurements with a high temporal and spatial resolution. To present the temporal and spatial variation of TEC during the storm, differential TEC maps relative to a quiet day (November 6, 2004) were created. The features of geomagnetic storm attributed to the complex development of ionospheric storm depend on latitude, longitude and local time. The positive, as well as negative effects were detected in TEC variations as a consequence of the evolution of the geomagnetic storm. The maximal effect was registered in the subauroral/auroral ionosphere during substorm activity in the evening and night period. The latitudinal profiles obtained from TEC maps for Europe gave rise to the storm-time dynamic of the ionospheric trough, which was detected on November 7 and 9 at latitudes below 50°N. In the report, features of the response of TEC to the storm for European and North American sectors are analyzed.     

海洋风暴形成的一种动力学机制

文中从观测统计学、瞬变涡动能量学和 MM5中尺度数值模拟角度 ,研究了海洋风暴 (爆发性气旋 )形成的气候特征及其可能的动力学机制 ,揭示了一幅爆发性发展的物理图像。结果表明 ,在冷季大气特别是日本以东洋面上大气特有的热力气候背景下 ,通过同海洋风暴过程相联系的涡动热通量 vθ的向极地输送 (- vθ· θm>0 ) ,将季节尺度的时间平均有效位能向瞬变涡旋时间尺度的涡动有效位能转换 ,是海洋风暴形成的主要动力机制。在该过程中转换来的具有最大贡献的涡动有效位能 ,连同具有次大贡献的积云加热制造的涡动有效位能(q3 )一起 ,通过暖异常区 (α >0 )暖湿空气上升运动 (-ω >0 )的斜压转换 (-ωα) ,促使涡动动能增长。同时 ,补充的涡动有效位能又加强了暖异常区的暖湿空气上升运动 ,进而产生积云对流活动及其潜热释放的正反馈过程 ,最终导致涡动动能急剧增长和海洋风暴的形成。海-气潜热输送的作用是在风暴形成初期提供后来积云尺度对流活动及潜热释放的水汽潜力。研究还表明 ,海洋风暴主要发生在冷季月份 1 3 0°E以东的中高纬洋面上 ,这种对特定季节和特定海域的依赖性是大气和海洋气候背景的动力 /热力共同作用的结果     

Sand-dust storms in China: temporal-spatial distribution and tracks of source lands

1 IntroductionSand-dust storms include both sand storms and dust storms[1]. When the visibility in local areas is greater than or equal to 50 m but less than 200 m, they are called severe sand-dust storms. When extremely severe sand-dust storm, the most severest type of sand-dust storm, occurs, the local instantaneous maximum wind speed can be greater than 25 m/s and a local visibility be less than 50 m or even descend to 0 m[2].Sand-dust storm is a critical environmental problem and is also a…