对临汾人工影响天气工作的调研报告

人工增雨防雹是直接为工农业生产服务的公益性事业,有利于促进草木植被生长,可有效地扑救森林、草场火灾,是保护和改善生态环境的重要措施;可以减轻大气污染程度,改善空气质量,有益于人们的身心健康;可以缓解工业、农业和人民生活用水供需矛盾,促进社会经济可持续发展。分析表明,凡是降水量明显偏少的年份,粮食大都减产;年降雨量多的年份,粮食大都增产。这表明,人工增雨消雹对于经济建设和社会发展尤其是对农业生产有着重要的意义。     

Properties and stability of a meso-scale line-form disturbance

By using the 3D dynamic equations for small- and meso-scale disturbances, an investigation is performed on the heterotropic instability (including symmetric instability and traversal-type instability) of a zonal line-like disturbance moving at any angle with respect to basic flow, arriving at the following results: (1) with linear shear available, the heterotropic instability of the disturbance will occur only when flow shearing happens in the direction of the line-like disturbance movement or in the direction perpendicular to the disturbance movement, with the heterotropic instability showing the instability of the internal inertial gravity wave; (2) in the presence of second-order non-linear shear, the disturbance of the heterotropic instability includes internal inertial gravity and vortex Rossby waves. For the zonal line-form disturbance under study, the vortex Rossby wave has its source in the second-order shear of meridional basic wind speed in the flow and propagates unidirectionally with respect to the meridional basic flow. As a mesoscale heterotropic instable disturbance, the vortex Rossby wave has its origin from the second shear of the flow in the direction perpendicular to the line-form disturbance and is independent of the condition in the direction parallel to the flow; (3) for general zonal line-like disturbances, if the second-order shear happens in the meridional wind speed, i.e., the second shear of the flow in the direction perpendicular to the line-form disturbance, then the heterotropic instability of the disturbance is likely to be the instability of a mixed Rossby–internal inertial gravity wave; (4) the symmetric instability is actually the instability of the internal inertial gravity wave. The second-order shear in the flow represents an instable factor for a symmetric-type disturbance; (5) the instability of a traversal-type disturbance is the instability of the internal inertial gravity wave when the basic flow is constant or only linearly sheared. With a second or nonlinear vertical shear of the basic flow taken into account, the instability of a traversal-type disturbance may be the instability of a mixed vortex Rossby – gravity wave.     

一次超级单体的多普勒雷达特征分析

运用长沙多普勒天气雷达的基本反射率因子(R)、径向速度(V)、垂直积分液态含水量(VIL)、垂直剖面等产品,分析了2008年4月8日发生在湘东地区的一次超级单体强对流天气过程。分析表明:这次过程是一次典型的超级单体过程,在反射率因子上出现了钩状回波、三体散射回波、弱回波、高悬垂回波,相应的径向速度图上出现了持久的中气旋,风暴顶表现为强烈的辐散,降雹前相应的液态垂直累积含水量有一个跃增,这些多普勒雷达特征均为超级单体风暴预警提供了有利的临近预报因子。     

海南异常高温的气候特征及其海气背景

分析1961～2001年海南5～7月异常高温频数的气候特征及其影响因子南海海温和北半球500hPa高度场特征,结果表明,5、6月异常高温频数分别存在3馏年和5年左右的显著周期;南海中部海域是影响同期异常高温频数的关键区域;异常高温频数偏多年,欧亚地区500hPa环流特征是中高纬度有阻塞高压存在,西风槽南压,西太平洋副热带高压位置长期偏南、偏西。     

宁夏区域精细化温度预报业务平台

介绍以宁夏中尺度数值模式温度预报为基础,以宁夏精细化预报系统温度预报产品为核心,结合自动气象站等多种资料,以图形方式显示、修改和制作宁夏各站逐时温度预报业务平台。该平台以宁夏各地区代表站与该地区其它站之间的回归方程的计算量为依据,在温度预报物理过程不变的情况下,通过修改曲线的方式,完成对大数据量温度预报值的订正。该平台的建成,为制作高时间密度的预报提供了技术支撑。     

谈谈建筑玻璃幕墙的防雷方法

对建筑玻璃幕墙的雷电危害及防雷措施进行分析,阐述玻璃幕墙防雷的有关做法。     

基于GIS的雷电数据可视化地图组件设计与实现

雷电发生发展于地理空间,具有明显的时空特性,因此在地理信息平台的支持下进行各种雷电数据空间及其属性特征分析具有重要的意义。在ArcEngine的基础上,设计研发了雷电数据可视化地图组件（Thunder Map）,按照数据定义层、数据功能层以及地图UI层的3层逻辑结构,实现了各种雷电相关数据基于地理信息平台的可视化表达,并提供了相关数据管理与功能分析的操作接口,为基于地理空间信息的雷电数据处理提供可视化的功能组件支持。     

Changing Trends of Daily Temperature Extremes with Different Intensities in China

By comparing two sets of quality-controlled daily temperature observation data with and without the inhomogeneity test and adjustment from 654 stations in China during 1956-2004 and 1956-2010, impacts of inhomogeneity on changing trends of four percentile temperature extreme indices, including occurrences of cold days, cold nights, warm days, and warm nights with varying intensities, were discussed. It is found that the inhomogeneity affected the long-term trends averaged over extensive regions limitedly. In order to minimize the inhomogeneity impact, the 83 stations identified with obvious inhomogeneity impacts were removed, and an updated analysis of changing trends of the four temperature extreme indices with varying intensities during 1956-2010 was conducted. The results show that annual occurrences of both cold nights and cold days decreased greatly while those of warm nights and warm days increased significantly during the recent 20 years. The more extreme the event is, the greater the magnitude of changing trends for the temperature extreme index is. An obvious increasing trend was observed in annual occurrences of cold days and cold nights in the recent four years. The magnitude of changing trends of warm extreme indices was greater than that of cold extreme indices, and it was greater in northern China than in southern China. Trends for summer occurrence of cold days were not significant. Decreasing trends of occurrences of both cold nights and cold days were the greatest in December, January, and February (DJF) but the least in June, July, and August (JJA), while increasing trends of warm nights were the greatest in JJA. Cold nights significantly decreased from 1956 to 1990, and then the decreasing trend considerably weakened. The decreasing trend also showed an obvious slowdown in recent years for occurrence of cold days. However, increasing trends of warm nights and warm days both have been accelerated continuously since the recent decades. Further analysis presents that the evolution of the trends for occurrences of the four temperature extreme indices was dominated by the changes in northern China.     

青岛市气象局网络安全管理系统

网络安全是影响气象通信网络性能和功能的重要因素。从线路设备、安全设备和措施、安全管理制度3个方面结合青岛市气象局具体情况进行了网络安全系统建设的介绍,内容包括通信线路的冗余、核心设备的热备份、网络安全设备的应用和安全控制策略、用户和管理员安全管理规定,并详细介绍了防火墙配置、核心交换机热备、关键服务器的访问控制等关键技术的实现,最后根据网络安全建设经验对地市级气象局的网络安全建设提出了一些建议。     

北京一次冬季回流暴雪天气过程的数值分析

回流天气是华北地区冬、春、秋季节产生降雨（雪）的主要天气类型,预报员常常因对回流天气系统结构特征认识不足和诊断失误而导致预报的失败,是降雨（雪）预报的难点和重点。利用北京地区高分辨率快速循环同化中尺度数值预报系统（BJ-RUC）对2010年1月2—3日一次典型的回流暴雪天气过程进行模拟,分析数值模式的模拟能力,研究各层主要影响系统结构特征及形成暴雪的关键性条件,探讨典型回流暴雪天气过程的形成机理。主要结论为：数值模式对此次暴雪过程的近地面回流冷空气、中低层低值系统及变化特征、主要降雪时段和降雪量模拟效果较好,对降雪落区的模拟存在一定偏差。低层回流偏东风遇到地形后引起垂直运动主要在低层800 hPa以下,所产生的降雪量不大,而其与上游850～700 hPa低涡系统发展东移其前部的上升运动汇合所形成的大范围、深厚、强烈的上升运动是产生明显降雪的关键性条件。上游低涡系统前部西南暖湿气流相对应的大湿度区移近是产生较强降雪的重要条件。持续的低层回流冷空气湿度较大,对于低层大气起到水汽输送的作用。回流冷空气使低层大气维持长时间的水汽输送并与其上层东移的大湿度区相结合,增加湿层厚度,有利于降雪持续而形成较强降雪。降雪开始时间和降雪强度的变化与对流层中下转偏南风的时间和偏南风风速增大有关。