组播技术在软件电视天气会商系统网络集成中的应用

利用组播技术,解决了网络资源被大量占用问题,完成了话音、数据、视频稳定传输,实现了宽带网中软件电视天气会商功能,通过市县间的业务试运行表明组播技术是目前软件电视天气会商系统中最核心的适用技术之一.     

新疆天气预报电视会商系统

新疆气象局通过现有宽带网络已经建立了视频会商会议系统,通过该系统可以实现全疆区地天气会商,同时还可以方便快捷的召开省内电视电话会议、举办业务培训、进行学术报告会等.本文主要介绍新疆视频会议系统的建设及概况.     

网上天气会商系统

简要介绍网上天气会商系统的技术特点和功能特点,并重点介绍系统中用到的一些关键技术及其实现方法.     

2012国家气象体验之旅——河南行

了解天气预报制作过程同学们首先参观了河南省气象台,活动从观摩全国天气会商开始,中小学生们通过观看天气会商初步了解了气象部门是如何对天气过程进行“会诊”的。     

省地视频天气会商系统建设与技术探讨

建设视频天气会商系统可以促进气象业务服务工作,通过对中国气象局视频天气会商系统组成的分析,对贵州、湖南省地视频天气会商系统的结构形式和实际使用效果的分析比较,找出了2套省地视频天气会商系统的优势与不足,提出现有条件下视频技术改进和系统完善的适用办法,并对拓展系统应用,充分发挥系统建设整体效益的技术措施进行了探讨,可供当前省地气象业务现代化建设参考借鉴。     

新一代天气会商和预警显示系统简介

新一代天气会商和预警显示系统是融合天气会商和预警信息显示的新一代多功能系统.该系统不但可以实现预警和警告信息自动动态更新显示功能,而且还可以进行天气会商,同时操作非常简单实用,维护方便快捷.     

自治区气象台首次召开联合会商会

3月5日上午,针对未来先升温后冷空气入侵天气,区气象台组织了天气大会商,史玉光局长及业务管理处、遥感中心、农气中心、气候中心的领导和专家参加了会商。下午,区气象台又邀请了自治区防洪办、新疆水文局、新疆地质环境监测院等部门的专家进行了联合会商,对这场天气是否会引起     

贵州省气象视频会商保障体系构建分析

视频会商系统是气象部门开展省地县三级天气会商、远程培训、行政会议等业务活动的重要系统平台。贵州省气象信息中心视频会商系统以网络音视频数字化平台为基础,主控室为核心,各会议室采用基于标准网络的分布式架构,与管理中心实现实时数据共享、交互。在会商过程中,要求音频、视频、网络、调度管理系统等多个要素高度协调、有机组合,但保障人员对偶发性的硬件或软件系统故障难以迅速定位排除,与会商过程的高实时性要求不相适应,因此会商保障工作应在会前充分准备,会中及时应对,会后总结改进。因此,构建良好的气象视频会商保障体系是提高保障水平,节省人力成本的有效途径。     

气象云会商系统的设计及应用

气象部门素来有通过视频会议进行天气会商的传统,但受限于技术条件,多年以来天气会商只能在气象部门内网环境中进行。为满足用户基于互联网接入天气会商的需要,国家气象信息中心于2019年建设完成了气象云会商系统。该系统依托国产的互联网视频会议产品,采用专有云方式进行了部署,并实现了与气象部门已有的基于H.323协议视频会议系统的融合对接。通过在多个云会商系统间设置友好企业方式,不仅满足了气象部门系统分级和属地化管理的要求,也极大的提升了跨部门会商联动的简便性。本文对该系统的设计方案及关键技术进行了阐述,并介绍了其在重大活动气象服务及气象部门迎战新冠肺炎疫情过程中的应用效果,也提出了下一步云会商业务的发展方向。     

如何利用即时通讯软件实现远程天气预报会商

会商是天气预报中的一个重要环节,尤其在遇到重要天气过程时,本地气象台站通常要与周边兄弟气象台站进行远程会商。目前,省内天气会商普遍依托9210工程卫星网络进行。其具体做法是,各会商台站将预报结论以文档形式传送到省一级气象台服务器汇总后,再从该服务器上调阅省内各台站的预报结论文档。这种会商方法的主要缺陷是,无法交流预报的理由或依据,更不能实现语言交流和可视化。     

加强业务管理提高测报质量

我局从1999～2003年,测报工作连续4年未出现错情,在此期间共有1个250个班,9个百班无错通过上级业务部门验收.在仪器保管、使用、维护上符合要求,对外报送的各种表、簿都能做好出门合格.     

Comparing the theoretical versions of the Beaufort scale, the T-Scale and the Fujita scale

2005 is the bicentenary of the Beaufort Scale and its wind-speed codes: the marine version in 1805 and the land version later. In the 1920s when anemometers had come into general use, the Beaufort Scale was quantified by a formula based on experiment. In the early 1970s two tornado wind-speed scales were proposed: (1) an International T-Scale based on the Beaufort Scale; and (2) Fujita's damage scale developed for North America. The International Beaufort Scale and the T-Scale share a common root in having an integral theoretical relationship with an established scientific basis, whereas Fujita's Scale introduces criteria that make its intensities non-integral with Beaufort. Forces on the T-Scale, where T stands for Tornado force, span the range 0 to 10 which is highly useful world wide. The shorter range of Fujita's Scale (0 to 5) is acceptable for American use but less convenient elsewhere. To illustrate the simplicity of the decimal T-Scale, mean hurricane wind speed of Beaufort 12 is T2 on the T-Scale but F1.121 on the F-Scale; while a tornado wind speed of T9 (= B26) becomes F4.761. However, the three wind scales can be uni-fied by either making F-Scale numbers exactly half the magnitude of T-Scale numbers [i.e. F′half = T / 2 = (B / 4) − 4] or by doubling the numbers of this revised version to give integral equivalence with the T-Scale. The result is a decimal formula F′double = T = (B / 2) − 4 named the TF-Scale where TF stands for Tornado Force. This harmonious 10-digit scale has all the criteria needed for world-wide practical effectiveness.     

准两年振荡对大气中微量气体分布的影响

NCAR的包含化学、辐射、动力相互作用的两维模式（SOCRATES）移植回国后进行了初步的模拟试验,用以研究某些对环境问题重要的微量气体的化学、辐射、动力传输过程。在不考虑极地平流层云和气溶胶表面非均相化学等情况下,模式积分多年,计算结果稳定,模拟的风场、温度场显示出正常的季节变化,模拟的微量气体分布与卫星实测资料对照,结果也比较一致。为了探讨热带平流层风场的准两年周期振荡（QBO）对平流层微量气体分布的影响,我们做了QBO强迫的数值试验,即在模式中加入QBO强迫,并与不考虑QBO强迫的模拟结果对比。结果表明,QBO与其相关的次级环流所引起动力输送的变化,使平流层微量气体分布发生变化。     

Quantifying the uncertainty of the annular mode time scale and the role of the stratosphere

The impact of high resolution modern vegetation cover on the West African climate is examined using the International Centre for Theoretical Physics Regional Climate Model implementing the NCAR Community Land Model. Two high resolution 25 km long-term simulations driven by the output from a coarser 50-km resolution simulation are performed for the period 1998–2010. One high resolution simulation uses an earlier and coarser-resolution version of plant functional type distribution and leaf area index, while the other uses a more recent, higher-quality, and finer-resolution version of the data. The results indicate that the new land cover distribution substantially alters the distribution of temperature with warming in Central Nigeria, northern Gulf of Guinea and part of the Sahel due to the replacement of C4 grass with corn; and cooling along the coastlines of the Gulf of Guinea and in Central Africa due to the replacement of C4 grass with tropical broadleaf evergreen trees. Changes in latent heat flux appear to be largely responsible for these temperature changes with a net decrease (increase) in regions of warming (cooling). The improved land cover distribution also results in a wetter monsoon season. The presence of corn tends to favor larger precipitation amounts via more intense events, while the presence of tropical broadleaf evergreen trees tends to favor the occurrence of both more intense and more frequent events. The wetter conditions appear to be sustained via (1) an enhanced soil moisture feedback; and (2) elevated moisture transport due to increased low-level convergence in regions south of 10N where the most substantial land cover differences are present. Overall the changes induced by the improved vegetation cover improve, to some extent, the performance of the high resolution regional climate model in simulating the main West African summer monsoon features.     

流场配置及地形对西南低涡形成的动力作用

本文采用定常二层模式讨论较小地形及高、低层流场配置对西南低涡形成的动力作用。指出了西南低涡的形成是与盆地、河谷以及其上气流分层有关的一种定常态.在上、下为西风分层时期,低层的浅薄暖湿西风有利于西南低涡的形成.在上、下为东、西风分层时期,上层浅薄东风亦有利于西南低涡的形成.小型的凸起山脉对西南低涡的形成没有作用.     

由中国历史气候记录对季风导致唐朝灭亡说的质疑

2007年1月4日杂志发表了Yancheva等10人的题为"Influence of the intertropical convergence zone on the East-Asian monsoon"(热带辐合带对东亚季风的影响)的论文[1],这是德国波兹坦地学研究中心气候动力与沉积学科的主管豪格(G.H.Haug)率领的科研小组的一项成果,认为是季风的变化引起的长期干旱导致了唐朝的灭亡.     

On the forecast of the onset and end of the convective season in the Amazon

Summary ?Some features of the climate system that can be considered predictors of the onset and end of the convective season over the Amazon were identified using one-month lag correlations and field composites. The fields analyzed were sea surface temperature (SST), outgoing long-wave radiation (OLR), vertical velocity and upper tropospheric winds. Warm (cold) anomalies in the SST in the tropical North Atlantic and the Caribbean Sea tend to be associated with delayed (early) onsets. Likewise, there is a tendency towards a delayed (early) end of the convective season with cold (warm) anomalies in these ocean regions. In addition, the SST in the cold tongue region of the equatorial Pacific is negatively, though weakly correlated with the onset date. The signal of this SST is more evident in the case of the end date, which is earlier with respect to its mean date in most of El Ni?o cases. The convective activity intensity itself conditions the onset and the end of the convective season, as it is evidenced by the behavior of the OLR and the vertical velocity fields. The more (less) intense the convective activity over South America during the preceding month, the earlier the onset and the later the end of the convective season on the Amazon region. The prediction of the onset and end dates of the convective season in the Amazon region was explored using a simple multiple regression technique based on the variables that have shown precursor signals with respect to these dates. The correlation coefficient between the predicted and the observed onset date is 0.81, and in the case of the end date, it is 0.76. The skill to predict early, delayed and normal categories was high, since in more than two thirds of the cases the category was successfully predicted, and there were no predictions of categories opposed to those observed. Received July 23, 2001; revised February 22, 2002; accepted April 26, 2002     

Analysis of the Characteristics of the Low-level Jets in the Middle Reaches of the Yangtze River during the Mei-yu Season

Here, we analyze the characteristics and the formation mechanisms of low-level jets(LLJs) in the middle reaches of the Yangtze River during the 2010 mei-yu season using Wuhan station radiosonde data and the fifth generation of the European Centre for Medium-Range Weather Forecasts(ERA5) reanalysis dataset. Our results show that the vertical structure of LLJs is characterized by a predominance of boundary layer jets(BLJs) concentrated at heights of 900–1200 m.The BLJs occur most frequently at 230...