多模式温度集成预报

基于中国国家气象中心T213模式、德国气象局业务模式和日本气象厅业务模式2 m高温度预报, 利用神经网络方法中的BP网络建立了我国600多个站的温度集成预报系统, 该预报系统的预报时效为72 h, 间隔为3 h。通过对2004年1—5月的预报结果检验, 表明:集成的温度预报结果明显优于3个模式单独的预报结果, 72 h内预报的平均绝对误差在3 ℃以内, 并且不存在明显的系统误差, 预报达到了一定的精度, 可以为预报员提供定时、定点精细的客观温度预报参考。分区的检验结果表明:不同区域预报误差存在差别, 新疆和西藏误差比较大, 而长江流域和华南地区误差很小, 并且不同区域系统误差的情况也不相同。从总体情况看, 预报误差还存在日变化, 一般来讲, 夜间的预报误差小于白天。     

基于模式预报倾向的预报系统设计与初步试验

为了充分利用数值模式的预报产品信息,首先对数值模式预报产品的误差进行了分析,针对误差分析结果,首次提出了一种新的基于模式预报倾向的精细化预报方法,并在此基础上设计开发了新疆精细化数值预报系统。初步试验结果表明:该方法对新疆地区的温度预报具有一定的正效果。后期经过调整订正系数,利用更多时次的观测资料进行温度订正,则有望可以使订正的温度更加接近观测。即该方法可以提高气象台站的温度预报准确率,展现了该方法的业务应用潜力。     

基于瑞万思温度预报制作咸阳市客观温度预报方法

对咸阳市12县（市）半年内逐日24-72 h＂瑞万思天气预测辅助信息系统＂（简称＂瑞万思＂）、＂德国天气在线＂与＂兰州区域气象中心业务产品网＂的温度预报准确率进行对比分析,发现瑞万思对咸阳市温度预报具有较高的指示作用,值得借鉴;对瑞万思的温度预报值与实况值进行趋势、误差分析,并对瑞万思温度预报进行两种3 d滑动误差计算,发现3 d滑动误差可有效改善瑞万思系统性误差;以其制作的咸阳市客观温度预报方法准确率明显提高,在常规温度要素预报业务中起到指导作用。     

德国天气在线产品在寿光温度预报中的应用分析

为了提高更加精细化的温度预报,通过对2009-2010年德国天气在线的数值预报产品中24小时最高、最低气温进行检验,结果表明,在士2℃误差范围内,德国天气在线的数值预报产品对高温预报准确率平均达到78％;低温预报准确率平均达49％。分析影响该模式预报高、低温偏差的主要天气原因,找到通过该模式订正高、低温预报的方法。     

临沂中尺度数值预报系统及应用

介绍了临沂中尺度数值预报系统及预报产品的释用和模式系统应用雷达资料情况,并对2005年6~10月的业务运行结果进行了检验,对小雨和中雨预报效果较好,TS评分较高,对夜间温度预报平均值绝对误差在1.52~2.52℃之间,平均均方根误差在2.01~2.93℃之间。该系统降水预报质量较高,气温预报误差小,准确率高,对定时、定点、定量的精细化预报具有较高的参考价值。应用自主开发的SDAF软件包,对系统的预报产品进行释用,研制了暴雨、空气质量、极端气温、干热风等预报方法。将多普勒雷达回波强度加入模式,改变模式水汽场,明显改进了预报。对径向速度反演降水系统内部风场进入中尺度模式进行了初步试验,得出了一些有益结论。     

长江上游流域数值预报产品误差分析与订正系统的设计与实现

为满足长江上游流域梯级水利枢纽的运行生产对精细化气象服务的需求,设计研发了长江上游流域数值预报产品误差分析与订正系统。该系统实现了长江上游流域内T639、欧洲、日本等数值模式预报产品及实况的实时收集处理和误差统计对比分析,提供了降水和数值预报天气形势场的自动客观订正产品,同时通过图形化界面的预报产品主观订正平台,实现了长江上游降水预报产品的制作输出以及各类误差分析数据的统计查询、对比显示,为综合有效的利用多种预报产品开展流域高质量、精细化的预报业务提供了支撑。该系统已在三峡梯调通信中心投入业务运行,运行情况表明该系统运行稳定、操作方便,具有较好的订正效果,在流域强降水天气过程的预报服务中发挥了重要作用。     

T63模式对暴雨短期预报能力的分析检验

利用Ｔ６３模式的５００ｈＰａ数值形势预报图和客观分析实况图，对１９９４年７－９月我国出现的１２次较大范围暴－大暴雨天气过程的影响天气系统进行了预报能力的分析检验，并分析了产生误差的原因，所得结果有利于数值预报产品的释用及实时预报业务。     

区域增强模式数值预报系统及其性能

介绍一个新的中尺度模式业务数值预报系统，即区域增强模式数值预报系统，该系统具有较高的分辨率，并能在广州区域气象中心现有条件下进行实时业务预报。大量准业务预报试验表明，该系统对影响华南的种类主要大气过程、尤其是台风和前汛期暴雨等过程有较强的预报能力。对１９９３、１９９４、１９９５年所有影响华南的台风过程的预报检验其降水邓产分明显高于国家气象中心降水预报模式等大尺度模式的预报，同时，台风路径的预报误差     

新型天气预报业务系统框架

在兰州区域气象中心ＤＥＣ业务网络下运行的新型天气预报业务系统,对西北地区东部的重要天气,按中短期预报时效,以模块的方式建立预报系统;以引进人工智能神经元网络技术,预报甘肃省降水天气。该系统经试运行,具有业务实用性强、预报效果较好等特点     

集合敏感性在预报误差及可预报性研究中的应用进展综述

研究大气的可预报性和预报误差产生的原因,对于改进数值预报,提升业务预报技巧具有重要意义。集合敏感性基于具有流依赖特性的集合预报,通过建立预报与初始场或前期预报大气状态之间的统计关系,为揭示与预报对象可预报性相关的动力学特征及理解预报误差来源和传播机制提供了一种新方法。同时,介绍了集合敏感性的定义和度量,并综述了其针对典型天气系统和高影响天气事件研究的进展,并讨论了该方法的优势和局限性。     

A meteorological 80-m tower near Rotterdam

Construction, observation site and instrumentation are described of an 80-m meteorological observation tower, erected in Vlaardingen, The Netherlands, for studies in connection with air pollution problems along the Nieuwe Waterweg. From measurements made regularly in the period April 1967–April 1968 summaries are given of wind profile parameters and gustiness averages. Case histories are presented of an air pollution episode lasting several days, and of an hourly average wind direction difference of 120 ° over 70 m.     

Neo-Atlantis: The Netherlands under a 5-m sea level rise

What could happen to the Netherlands if, in 2030, the sea level starts to rise and eventually, after 100 years, a sea level of 5 m above current level would be reached? This question is addressed by studying literature, by interviewing experts in widely differing fields, and by holding an expert workshop on this question. Although most experts believe that geomorphology and current engineering skills would enable the country to largely maintain its territorial integrity, there are reasons to assume that this is not likely to happen. Social processes that precede important political decisions – such as the growth of the belief in the reality of sea level rise and the framing of such decisions in a proper political context (policy window) – evolve slowly. A flood disaster would speed up the decision-making process. The shared opinion of the experts surveyed is that eventually part of the Netherlands would be abandoned.     

Strong gusts in the lowest 250-m layer over the city of Tokyo

From the architectural point of view, the vertical distribution of strong gusts over large cities is very important. Although special instrumentation for very strong winds is required, the available recording devices are generally not adequate. Only rather recently have telemetric techniques advanced sufficiently to ensure a practical system for measuring very strong gusts. Records from fast-response anemometers for each minute (sixty measurements per hour) may clarify the physical processes in the atmospheric boundary layer in the lowest 250-m layer over the city of Tokyo. The new system can be considered practical since it was operated from May 1968 to July 1969 under a variety of climatic conditions, especially under strong gusty conditions.     

基于北京325米气象塔观测的正,负湍流热扩散系数

本文基于K理论和北京325m铁塔湍流观测资料直接计算了城市污染条件下的湍流热扩散系数H.KH具有明显的日变化特征,其垂直分布随个例和时间而变化.负KH较高发生频率对应高度在日出后逐渐升高,在中午达到峰值,在日落附近下降,而在夜间大部分时间集中在140 m左右.和传输和清除阶段相比,污染物累积阶段的KH大小和波动程度均较小.此阶段PM2.5浓度与KH绝对值之间的负相关关系表明湍流扩散可能会极大地影响PM2.5浓度.这些发现可能为建立新湍流扩散参数化方案提供有价值的启示.     

基于统一高度Cressman方法的地面2m气温客观分析

针对离散站点资料格点化的业务需求及 Cressman 方法在地形复杂区域客观分析存在的问 题,利用山东及周边省自动气象站观测的 2 m气温和 ECMWF预报的海上 2 m气温,结合山东省中尺度数值预报位温递减率、90 m分辨率 SRTM高程数据,采用统一高度 Cressman 方法对山东省地面2 m气温进行客观分析,生成了逐 1 h、0.01°×0.01°高分辨率的地面 2 m气温格点产品。结果表明,统一高度 Cressman 方法的客观分析格点产品在地形复杂区域的分析更合理,月平均误差基本在±1 ℃以内,鲁中山区地形高度较高区域月平均误差略大于鲁西北、鲁西南、鲁东南和山东半岛等地的平原地区,气温偏低的10、11、12月温度准确率均略低于 5、6、7、8、9 月;2020 年 5—12 月平均误差为－0.0039 ℃,平均绝对误差为 0.1469 ℃,均方根误差为 0.3597 ℃,2 ℃以内准确率为 99.64%,1 ℃以内准确率为 98.24%,各项检验指标均较优。总体上统一高度 Cressman 客观分析格点产品质量接近中国气象局陆面数据同化系统（ HRCLDAS ）高分辨率格点实况产品。     

Simulating the impact of the large-scale circulation on the 2-m temperature and precipitation climatology

The impact of the simulated large-scale atmospheric circulation on the regional climate is examined using the Weather Research and Forecasting (WRF) model as a regional climate model. The purpose is to understand the potential need for interior grid nudging for dynamical downscaling of global climate model (GCM) output for air quality applications under a changing climate. In this study we downscale the NCEP-Department of Energy Atmospheric Model Intercomparison Project (AMIP-II) Reanalysis using three continuous 20-year WRF simulations: one simulation without interior grid nudging and two using different interior grid nudging methods. The biases in 2-m temperature and precipitation for the simulation without interior grid nudging are unreasonably large with respect to the North American Regional Reanalysis (NARR) over the eastern half of the contiguous United States (CONUS) during the summer when air quality concerns are most relevant. This study examines how these differences arise from errors in predicting the large-scale atmospheric circulation. It is demonstrated that the Bermuda high, which strongly influences the regional climate for much of the eastern half of the CONUS during the summer, is poorly simulated without interior grid nudging. In particular, two summers when the Bermuda high was west (1993) and east (2003) of its climatological position are chosen to illustrate problems in the large-scale atmospheric circulation anomalies. For both summers, WRF without interior grid nudging fails to simulate the placement of the upper-level anticyclonic (1993) and cyclonic (2003) circulation anomalies. The displacement of the large-scale circulation impacts the lower atmosphere moisture transport and precipitable water, affecting the convective environment and precipitation. Using interior grid nudging improves the large-scale circulation aloft and moisture transport/precipitable water anomalies, thereby improving the simulated 2-m temperature and precipitation. The results demonstrate that constraining the RCM to the large-scale features in the driving fields improves the overall accuracy of the simulated regional climate, and suggest that in the absence of such a constraint, the RCM will likely misrepresent important large-scale shifts in the atmospheric circulation under a future climate.     

A primary study of the variations of vertical radiation with the Beijing 325-m Meteorological Tower

The Beijing 325-m Meteorological Tower (325MT) is used to observe the vertical variation of solar radiation. Results of the experiments indicate that the automatic radiation monitoring system, including a sun tracker and data collection system, works well and all the specifications meet WMO observation standards. The measurement data show that there is a significant radiation decrease from 320m to the surface, where the difference is only about 30Wm^-2 on light air-pollution days, while the maximum reaches about 110Wm^-2 when heavy pollution appears near the ground. The global UV radiation decreases on heavy air-pollution days and under poor visibility conditions, and the difference between 300m and 8m is larger than on clear days.     

大连地区ECMWF细网格10 m风场与观测实况对比与检验

选取2016年1月至2018年12月ECMWF（简称EC）细网格10 m风资料,与大连地区8个国家气象观测站地面各类实况风速资料进行对比分析,得出EC 10 m风速预报与最大风速最为接近,与极大风速相关性最好,EC 10 m风速对大连地区8站整体预报平均偏大。通过对EC 10 m风速各预报时限资料与其对应的最大风速误差进行统计分析。结果表明：按实况分类,从风速平均误差来看,实况3级与预报最接近,小于3级时预报偏大,大于3级时预报偏小,各风向间的风速误差也比较明显,但比风级间的误差要小一些;平均绝对误差则是2—3级最小。各时限风速平均误差相差不大,基本在0.1—0.3 m·s^-1间,平均绝对误差则随时限延长呈缓慢增大趋势。风速误差具有明显的日变化,表现出白天小、夜间大、午后最小、下半夜最大的特征。风速误差也因测站不同,在不同风级和风向的反应也各不相同。     

Characteristics of the lower 1000-m atmospheric layer in the area of the Leningrad NPP-2

The calculated aeroclimatic characteristics of the lower 1000-m atmospheric layer needed to study the conditions for the atmospheric diffusion of pollutants are considered. The measurements of temperature profiles with the MTP-5 microwave temperature profiler and the data of weather balloon observations on wind speed and wind direction from the special meteorological station located at the Leningrad NPP-2 (LNPP-2) construction site are used as initial data. The characteristics of the vertical distribution of temperature and wind obtained from the observations in the LNPP-2 construction area and at the Voeikovo upper-air network station are compared.