南极中山站极夜、极昼期间S_q~p、S_D的变化规律及特征

本文利用１９９１年度南极中山站的地磁资料，分析研究极夜（５、６、７月）及极昼（１１、１２月）期间Ｓ、ＳＤ的变化特征。研究结果表明，Ｈ、Ｄ、Ｚ三个分量的Ｓ、ＳＤ在极夜期间的变化幅度都小于极昼期间的变化幅度，Ｓ在世界时ＵＴ６时左右出现极值。这是由于在５、６、７月的太阳直射点在北半球，太阳紫外辐射和Ｘ射线辐射减少，在１１、１２月太阳的直射点在南半球，太阳紫外线和Ｘ射线辐射增大，致使空间电高层等效电流发生变化所产生。     

陕西地方暴雨增强数值预报系统及其试验结果分析

该文介绍了陕西地方暴雨增数值预业务系统，并对１９９５年６－８月进行的降水准业务预报试验结果作了分析及Ｔｓ评分检验。结果表明：模式系统运行４８ｈ以上性能稳定，对陕西区域暴雨的预报效果较好，对日常业务预报有参考价值。     

地热异常区与降水异常区及地形变速率的关系

利用我国１９５４－１９９３年的季距平３．２ｍ地温资料，对“地热涡”的空间分布规律进行了统计分析。结果表明：一般其高频区与地形变速率绝对值的大值区对应，与降水异常的高频区基本对应，但中心位置大多偏离２００ｋｍ左右；其低频区与地形变速率弱的地区对应，与降水异常的低频区亦基本对应。     

关于夏季南亚高压的进一步研究Ⅰ.与我国西北地区降水关系的统计分析

为了进一步统一分析夏季１００ｈＰａ南亚高压脊线和中心位置与西北地区降水的关系，利用１９７０～１９８５年７～８月逐日历史天气图及降雨量等资料，统计了南亚高压脊线和中心活动的基本特征；划分了逐日东、西部型及带状型南亚高压及持续的东、西部型南亚高压过程，还区分了西北区东、西部的多雨、少雨日。结果表明：南亚高压脊线和中心位置（特别是持续的东、西部型南亚高压过程）与西北区东、西部多雨和少雨过程有密切联系     

对流凝结加热的垂直分布与低纬大气的30～60天低频振荡

运用一个包含Wave-CISK机制的斜压半地转8层模式和本征函数展开方法，研究了三种不同的对流凝结加热廓线对低纬大气的30—60天低频振荡的影响。研究表明，不同的加热廓线分布时30～60天低频振荡具有不同的相速和周期，并且低频振荡特征相速的量级都是o(10m／s)，由Wave-CISK机制激发的低频CISK—Kelvin波和CISK—Rossby波都是稳定的。同时，还进一步揭示了不同加热廓线对低纬大气30～60天低频振荡垂直结构的影响。     

天水市2002年4～6月降水、干旱趋势短期气候预测结果及成因分析

文中根据96—908—05—03西北地区干旱预测系统研究专题甘肃分专题“天水市干旱气候预测及对农业生产影响”子课题研究成果(系统从1998年开始投入业务运行)，对今年本地4—6月降水及干旱趋势的短期气候预测作了技术总结，并对其成因进行了初步分析。     

Estimation of regional meteorological and hydrological drought characteristics: a case study for Denmark

Information on regional drought characteristics provides critical information for adequate water resource management. This study introduces a method to calculate the probability of a specific area to be affected by a drought of a given severity and demonstrates its potential for calculating both meteorological and hydrological drought characteristics. The method is demonstrated using Denmark as a case study. The calculation procedure was applied to monthly precipitation and streamflow series separately, which were linearly transformed by the Empirical Orthogonal Functions (EOF) method. Denmark was divided into 260 grid-cells of 14×17 km, and the monthly mean and the EOF-weight coefficients were interpolated by kriging. The frequency distributions of the first two (streamflow) or three (precipitation) amplitude functions were then derived. By performing Monte Carlo simulations, amplitude functions corresponding to 1000 years of data were generated. Based on these simulated functions as well as interpolated mean and weight coefficients, long time series of precipitation and streamflow were simulated for each grid-cell. The probability distribution functions of the area covered by a drought and the drought deficit volumes were then derived and combined to produce drought severity-area-frequency curves. These curves allowed an estimation of the probability of an area of a certain extent to have a drought of a given severity, and thereby return periods could be assigned to historical drought events. A comparison of drought characteristics showed that streamflow droughts are less homogeneous over the region, less frequent and last for longer time periods than precipitation droughts.     

Précision de l'estimation des précipitations au Sahel selon la densité du réseau d'observation pluviométrique

Many earlier studies have shown the very large spatial variability of rainfall in the Sahel at all time steps, from the event to the season. Often, the meteorological network in these countries is sparse, with one to five rain gauges per 10 000 km². It is thus difficult to calculate accurate estimates of the mean rainfall over such a large area. To improve the knowledge of Sahelian systems and the spatial distribution of rainfall, a dense network was set up in an area of 16 000 km² in southwestern Niger between 1991 and 1996. The aim was to calculate accurate rainfall spatial means over an area of 12 000 km² at different time steps (from the season to the ten-day period). With the spatialisation method used (kriging), it was possible to calculate curves of estimation errors of mean rainfall versus the rain-gauge network density. Operational abacuses of the standard estimation error as a function of the spatial mean of rainfall and the network density are proposed.     

A STUDY ON THE RELATIONSHIP BETWEEN GMS-5 INFRARED DATA AND PRECIPITATION SOUNDED BY TRMM/PR

To study the possibility of improving the precision of retrieving precipitation through GMS-5infrared data,the relationship between the data of GMS-5 infrared channel 1(IR1)andprecipitation sounded by TRMM/PR was carefully studied through some cases gathered during theHUBEX 1998.First of all,the relationship between the brightness temperature(Tb)and PR-sounded near-surface rainfall rate(NSRR)was studied.Then,as PR can sound the innerstructure of rainfall area.a unique advantage of this new instrument,the relationship between Tband PR-sounded rainfall rate in each layer was also studied.Still,as PR can tell the rain type,those relationships were studied again according to the different types of precipitation(i.e.convective and stratiform).After comparing these outcomes with those from other references,itcan be concluded that the relationship between Tb and PR-sounded rainfall rate is acceptable and itis possible to calibrate precipitation retrieved through Tb by PR data.     

东营市季、年降水量与北半球500hPa高度场的相关关系及其预报

用滚动式相关分析方法分析了营市季、年降水量与500hPa高度场的相关关系。用相关显著的典型因子场做季、年降水量预报，效果良好。