714CD天气雷达监控故障分析诊断技巧

故障分析诊断技巧对气象大型装备可靠业务运行保障具有重要作用.714CD天气雷达在一次安装调试过程中,出现了伺服监控虚警的复杂故障.这次故障的特殊之处在于所有虚警点都与雷达的一个负2°状态继电器状态有关,在故障分析诊断过程中,透过相关报警内容的表面现象,找出故障共性的因素,依据伺服监控信号流程和关键点参数测量,最终排除了这一复杂故障,并从中总结出伺服监控三种类型故障分析诊断技巧:1)雷达伺服电路故障导致监控电路进行保护性停机;2)伺服监控电路故障导致雷达停机保护;3)出现监控虚警故障时,雷达运转正常或者错误行保护停机.依据故障现象和监控信号流程,论述了这三种故障的分析诊断技巧,以及故障排除方法.     

海口CINRAD/SA天气雷达频综故障分析

根据海口新一代天气雷达在运行过程中接收机频率源出现的故障现象,分析了SA雷达频率源的输出信号和功率测试方法,对海口频率源故障的定位、检测及排除过程作了详细介绍,分析导致此次故障的原因。     

南宁CINRAD／SA天气雷达无体扫产品故障浅析

描述南宁CINRAD/SA天气雷达出现无体扫产品故障的现象,介绍了故障定位和故障排除的过程,分析了导致此次故障的原因,讨论了CINRAD/SA天气雷达故障处理的一些方法.     

新一代天气雷达发射机速调管失效判断

1 故障现象及诊断分析处理 2008年2月5日,大连新一代天气雷达（CINRAD／SC）出现无回波现象,重启雷达仍无回波,天线转动正常,可以体扫,但无探测信息。     

CINRAD/SA雷达磁场电源调试与故障判定

阐述了CINRAD/SA雷达磁场电源控制电路,对磁场电源控制板电路的场效应管驱动信号、控制板驱动信号、IGBT模块极间电压波形等关键测试点进行了调试,并给出了相应的标准波形示意图,对磁场电源输出电压、磁场电源电压保护和聚焦线圈电流保护进行了分步调试,根据在实际使用过程中出现的故障现象、故障判定处理,结合实物测试点给出了故障处理流程图,结合实际工作经验总结了磁场电源的相关故障排查点和故障排除方法,旨在为雷达磁场电源的现场故障处理提供帮助和参考。     

一次多普勒天气雷达故障排除实例分析

根据雷达工作原理、故障现象和故障原因,对桂林市新一代多普勒天气雷达天线动态故障问题的维修工作的总结分析,找出故障原因,维护注意事项和维修方法.     

新一代天气雷达故障维修典型案例

针对新一代天气雷达（CINRAD/CB/CD）在内蒙古业务运行过程中所出现的一些典型故障,文章归纳总结了新一代天气雷达发射机故障、伺服系统故障、接收机噪声系数超标等几类典型故障的故障定位与故障排除方法,对雷达的日常维护和维修工作具有一定的参考价值。     

从接收机频综故障看新一代天气雷达的运行维护

结合4年多来宜昌新一代天气雷达的运行情况,针对困绕该雷达站达4年之久的接收机频综故障,按照及时处理和排除各种可能出现故障的要求入手,简单描述了其故障现象,从其硬件和软件两个方面分析了故障发生的原因,重点介绍了这一故障的处理步骤与方法。在此基础上,就操作维修人员该如何打牢分析处理雷达故障基本功,提出了三点建议。     

临汾新一代天气雷达的多起故障维修思路

近期临汾新一代天气雷达频繁出现发射机峰值功率小、无回波和终端显示乱码现象,不能正常工作,失去了对强对流天气和灾害性天气的监测,直接影响了雷达各类产品的生成和传输,也影响到为政府提供决策以及为社会各行各业的服务.为了解决这棘手问题,使雷达尽快恢复正常,山西省气象局大气探测技术保障中心、临汾市气象局以及厂家的技术人员一同对临汾新一代天气雷达进行了故障现象的观察、分析,经过认真地、有条不紊的工作,最后排除了所有故障,雷达恢复正常工作.     

多普勒天气雷达常见故障维修技巧

通过对CINRAD／CD型天气雷达的发射系统，接收系统，伺服系统及馈线系统工作原理的介绍，指出了各子系统易出现的故障现象原因，处理情况及日常维护注意事项。     

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.     

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     

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。     

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.     

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.     

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...     

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.     

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.