全球观测应力场的短波分量分析

世界应力图(WSM，World Stress Map)计划的应力指标，目前已累积数据共计10 920个，这些应力指标代表了该地区最大水平主应力的实际观测方向；与此同时，可以假定全球各个板块的绝对运动方向表征了相应各板块的最大水平主应力方向的长波分量．根据应力场的叠加原理，得到由该地区局部构造运动等因素贡献的短波分量的相对大小和方向．将全球划分成2.52.5的基本单元，对每个单元的WSM数据进行加权统计分析，得到其平均应力观测取向，利用HS2-NUVEL1全球绝对板块运动模型计算应力场的长波分量；平均观测应力取向和长波分量取向之间的夹角，决定了相应短波分量相对于观测应力场的大小及其取向的范围，并反映了特定研究地区局部应力场对总应力场的贡献程度．本文的计算结果表明，全球板块的绝大部分地区及各板块的平均效果，长波分量与短波分量对观测应力场的贡献程度相当．对于某些大陆板块内部，局部构造活动对观测应力场的贡献起到重要作用，因而控制着地震的孕育与发生．      

地震波研究://car

回顾了近4年来中国地球物理学家在地震波研究方面取得的主要进展. 分别简要地讨论了层状均匀介质、横向不均匀介质和多孔介质中的地震波传播，地震面波及波形反演，以及地震勘探、测井问题中的地震波研究方面取得的新成果. 指出当前地震波研究的重要课题是发展高效的数值方法，并利用该方法开展复杂介质中的地震波激发和传播，以及强地面运动的研究，为精细的地震危险分析与预测奠定基础.      

中国地震台网数字化改造的进展

介绍了九五期间（1996~2000年）中国地震台网数字化改造的进展和首都圈数字地震台网（1999~2001年）的建设情况，重点介绍了国家数字地震台网、区域数字地震台网和流动数字地震台网的台站分布、仪器配备和主要任务．      

兰州地区深部电性结构的初步研究

利用兰州地区现有的大地电磁资料，对该区的深部电性结构进行了初步研究。结果表明，兰州地区各地质构造单元的电性差异较明显，与区域构造有较好的对应性。     

地震灾害现场救援搜索策略与搜索方法有关问题的讨论

对地震灾害现场的搜索策略和搜索方法等有关问题进行了讨论，推荐了常用的搜索策略，对不同搜索方法的利弊进行了分析；对搜索方法的使用也做了讨论。通过讨论，文章就搜索分队的组成、任务、装备和部署等提出了建议。     

地震视应力用于震后趋势快速判定的可能性

对多次强震的地震视应力进行了计算，将各次强震的地震视应力的高低与强震发生后的后续地震的强度进行联系，探索它们之间的关系，进而提出将地震视应力用于强震震后趋势预测的可能性。对多次强震的地震视应力与其后续地震强度的关系的分析结果表明，低视应力的强震的后续地震的强度一般较低，即低视应力的强震发生后，震区发生较强的后续地震的可能性较小。     

Characteristics of the atmospheric heat source and moisture sink over the Qinghai-Tibetan Plateau during the second TIPEX of summer 1998 and their impact on surrounding monsoon

Summary ?Using the data of 6 automatic heat balance observation (AWS) stations and a data set of 52 surface observation stations over the Qinghai-Tibetan Plateau (“the Plateau”) and surroundings, the horizontal distribution is studied of “apparent atmospheric heat sources” 〈Q ₁〉 and of “apparent atmospheric moisture sinks” 〈Q ₂〉. The AWS stations were established during the period May to August 1998 of the Tibetan Plateau Meteorological Experiment (second TIPEX) by a cooperation of China and Japan. For this period the Plateau mean of 〈Q ₁〉 is positive. Its value of 74 W/m² is a little greater than a climate value and than values from MONEX and the first TIPEX in 1979, respectively. Also the corresponding 〈Q ₂〉 is positive. Hence during that time the Plateau is a heat source and a moisture sink. A day-to-day change of 〈Q ₁〉 and 〈Q ₂〉 is more pronounced over the middle and east part of the Plateau than over the west part. Diagnostics accompanied by numerical simulations are used to study the daily relationship between 〈Q ₁〉 over the Plateau and the weather over China and Asia for this summer. The results suggest that 〈Q ₁〉 may affect precipitation over northern China and position of the west Pacific subtropical high. Abnormal southward retreat of this Pacific high seems to have caused the second flood over the middle and lower Yangtse river basin in July. Received May 20, 2001; revised February 2, 2002     

Numerical simulation of a South China Sea typhoon Leo (1999)

Summary ?A South China Sea typhoon, Leo (1999), was simulated using the Penn State/NCAR mesoscale model MM5 with the Betts-Miller convective parameterization scheme (BMEX). The simulation had two nested domains with resolutions at 54 and 18 km, and the forecast duration was 36 hours. The model was quite successful in predicting the track, the rapid deepening, the central pressure, and the maximum wind speed of typhoon Leo as verified with reports from the Hong Kong Observatory (HKO). The structure of the eye, the eye wall, and the spiral convective cloud band simulated in the model are found to be comparable to corresponding features identified in satellite images for the storm, and also with those reported by other authors. A trajectory analysis was performed. Three kinds of trajectory were found: (1) spirally rising trajectories near the eye wall; (2) spirally rising/descending trajectories in the convective/cloud free belt; (3) straight and fast rising trajectories in a heavy convection zone along one of the cloud bands on the periphery of the tropical cyclone. Both the HKO and the U.S. Joint Typhoon Warning Center (JTWC) reported the rapid deepening of Leo started around 00 UTC 29 April. In the model, the eye was first formed in the lower troposphere, and it extended to the upper troposphere within a few hours. We speculate that the spin-up of cyclonic rotation in the low-level eye enhanced the positive vorticity along the low-level eye wall. The positive vorticity was then transported to the upper troposphere by convection, leading to an extension and growth of the eye into the upper troposphere. To examine the impact of convective parameterization scheme (CPS) on the simulation, the Grell scheme (GLEX) was also tested. The GLEX predicted a weaker typhoon with a wilder eye that extended not as high up in the upper troposphere as BMEX. The different structures of the eye between the BMEX and GLEX suggest that the mesoscale features of the eye are dependent on the convection. In other words, the vertical and horizontal distribution of convective heating is essential to the development and structure of the eye. Received December 18, 2001; accepted May 7, 2002 Published online: March 20, 2003     

陆面过程模式的改进及其检验

文中对陆面过程模式 (BATS)进行了改进 ,改进后的模式能较好地模拟地表物理量的年、季和日变化 ,它有两方面的特点 :采用热扩散方程模拟 7层土壤温度 ,模拟的温度可与实测值进行比较 ;在BATS的地表径流方案中 ,考虑了空间不均匀性的一般地表径流 (GVIC)过程 ,研究结果表明 :⑴模式能很好地模拟各层土壤温度的年、季和日变化。冬季土壤温度下层高于上层 ,而在夏季上层高于下层 ,这种上下层温度的转换时间大约在 4和 10月份 ,这与实测土壤温度的年变化非常一致。较为准确地模拟了各层土壤温度日变化的时滞效应。⑵用南京和武汉站的资料 ,将BATS地表径流方案模拟的地表水分分量与GVIC方案进行比较 ,BATS地表径流方案模拟的地表水分分量 ,与总水量的平衡相差较大 ,而GVIC模拟的效果相对较好 ,地表总水量基本上与降水总量达到了平衡     

ADP数字地震前兆综合观测台网系统的设计

介绍了ADP数字地震前兆综合观测台网系统的功能与结构。ADP系统已在广东省地震局连续运行，满足前兆台网综合化、数字化、自动网络化的要求。