“98．7”鄂东连续特大暴雨的中尺度分析（一）

使用10分钟间隔的武汉WSR－81S数字化雷达回波资料，结合逐时地面风场及雨量，对1998年7月20－21日出现在湖北省东部的特大暴雨过程进行了详细的中尺度分析。结果指出：地形对地面中－β尺度系统的发生发展起着重要的作用，对流回波的发生发展则与地面中－β尺度系统有着较好的对应关系，在对流层低层低钠的组织作用下，回波系统呈现出明显的涡旋运动，通过多次合并加强，最终造成特大暴雨。     

中国西北地区黑风暴与农业防灾减灾措施

本文通过对黑风暴的各种表现特征的描述，着重从“强风是黑风暴产生的动力；丰富的沙尘源是黑风暴形成的物质基础；不稳定的空气是重要的局地热力条件；形成黑风暴的形地貌因素；人为因素与黑风暴”等５个方面讨论了黑风暴的成因。     

The origins of kriging

In this article, kriging is equated with spatial optimal linear prediction, where the unknown random-process mean is estimated with the best linear unbiased estimator. This allows early appearances of (spatial) prediction techniques to be assessed in terms of how close they came to kriging.     

A CASE STUDY ON SANDSTORM

The favourable synoptic situation and climate background for a sandstorm process,which occurred in the period 9-16 April 1988,have been studied through analyzing weather maps,meteorological elements,satellite cloud pictures and sandstorm trajectories.The sand dust origin area,the directions and the paths of sand dust transport,and the extent the sand dust reached are also investigated.The results of measurments and analysis indicate that the concentration of sand dust particles is 10 times greater than the normal.It is also shown that the elements in the sand dust are lithophylic and come from natural source through the chemical composition analysis of the sand dust,so that the sand dust has not been polluted by human activities.     

Simulation of the movement and dispersion of oil slicks in the Arabian Gulf

The extensive oil drilling and transportation activities in the Arabian Gulf increased the possibility of oil spills and the consequent threat of oil pollution to the regional ecology. The available literature concerning the main aspects of the physical oceanographic characteristics affecting the movement and spreading of oil spill in the Gulf are reviewed. It is concluded that evaporation, wind-driven currents, and sandfall are important as weathering processes, while tidal currents cause lateral spreading of the slick. Oil spill modelling has shown some usefulness in estimating the trajectories of few major spills illustrated by reference to three models developed for the Gulf. The performance of these models, their capabilities and limitations are reviewed. Recommendations are made to gather more data on the behavior of oil spills in this particular environment.     

2017年9—11月T639、ECMWF及日本模式中期预报性能检验

对2017年9—11月T639、ECMWF及日本(文中简称JP)数值模式的中期预报产品进行了分析和检验,结果表明：三个模式对亚洲中高纬环流形势的调整和演变具有较好的预报性能。在中期时效内ECMWF能够较好地预报副热带高压的南北摆动和东西移动趋势,T639模式对副热带高压位置的预报易偏北。对850 hPa温度场,ECMWF模式的平均预报误差较小,预报性能较好,T639（JP）模式预报较实况偏低（偏高）。三个模式对台风玛娃中心位置的预报较零场偏西偏南,强度预报均偏弱,其中ECMWF模式对台风转向有所体现。对于冷空气过程中的海平面气压场预报,ECMWF模式对冷高压的强度预报与零场更为一致,而T639和JP模式的预报偏差较大。     

弱天气尺度背景下太行山极端短时强降水预报失败案例剖析

2015年7月31日夜间,太行山区出现极端短时强降水天气,石家庄和邢台的西部山区有5个雨量站雨量超过100mm,其中石家庄市赞皇县院头镇和邢台市临城县南中皋村最大雨强都超过50mm·h~(-1),3h雨量超过100mm,属极端短时强降水。数值预报、上级指导预报以及各级台站预报对暴雨均为漏报。本文利用常规高空地面观测资料、加密自动站观测资料、石家庄新一代天气雷达资料以及数值预报检验,反思该极端短时强降水预报思路和预报失败原因。此次极端短时强降水是发生在青藏高压东北侧高空西北气流的弱天气尺度背景下,预报的关键在于把握太行山东侧边界层偏东风与地形的作用、青藏高压加强使中层西北气流加强使垂直风切变加大、低层切变线东移影响、西南暖湿气流增强使水汽输送增加、中空干层与加厚的低空湿层叠加使对流不稳定性加强的特征。预报失误的主要原因是没有分析最大不稳定能量(订正CAPE值)导致对山西不稳定条件的低估,致使对山西雷暴在夜间的再次发展估计不足,同时预报员没能有效地使用非常规资料用于实时检验和订正数值预报结果,导致没能预见到雷暴下山增强的可能。目前对弱天气背景下强降水产生条件缺乏有效的概念模型,数值模式可预报性较差,未来需要提高预报员对观测资料的全面分析能力和对数值预报产品的释用能力,通过大量个例的研究发展有效的预报(概念)模型。     

基于WebGIS的农业气象业务平台的设计与实现

农业气象业务平台的建设对于保障农业由传统农业向高产、优质、高效、生态、安全和可持续发展的现代农业加快转变具有积极意义。以浙江全省地面气象观测网数据为基础,结合精细网格化气象要素预报产品、农业气象诊断指标、作物分布信息,研发了以气象指数为主的14类农业气象灾害监测预警指标、6类作物农用天气预报指标和水稻等作物生长发育动态诊断模型;基于B/S结构和ASP.NET开发平台,遵循SOA架构原则,采用C#、Java等计算机语言研制了基于WebGIS的浙江省省、市、县三级应用的农业气象业务平台。该平台集成了气象学、统计学、农学等研究领域的算法和模型进行跨领域数据分析,具备强大的定量及定性分析功能,平台操作简便、功能灵活,且支持自主构建评价体系,目前已经在浙江省省、市、县三级气象部门推广应用。     

Dynamical Feedback between Synoptic Eddy and Low-Frequency Flow as Simulated by BCC_CSM1.1(m)

Since the interaction between atmospheric synoptic eddy(SE)(2–8 days) activity and low-frequency(LF)(monthly)flow(referred to as SELF) plays an essential role in generating and maintaining dominant climate modes,an evaluation of the performance of BCC_CSM1.1(m) in simulating the SE feedback onto the LF flow is given in this paper.The model captures well the major spatial features of climatological eddy vorticity forcing,eddy-induced growth rate,and patterns of SELF feedback for the climate modes with large magnitudes in cold seasons and small magnitudes in warm seasons for both the Northern and Southern Hemisphere.As in observations,the eddy-induced growth rate and SELF feedback patterns in the model also show positive SE feedback.Overall,the relationships between SE and LF flow show that BCC_CSM1.1(m)satisfactorily captures the basic features of positive SE feedback,which demonstrates the simulation skill of the model for LF variability.Specifically,such an evaluation can help to find model biases of BCC_CSM1.1(m) in simulating SE feedback,which will provide a reference for the model's application.