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对L波段雷达探测系统在小场地风速过大时、施放气球困难、探空仪容易撞到建筑物或过顶,导致雷达无法自动跟踪、易抓旁瓣、容易造成记录缺测以致重放球等问题进行分析. 相似文献
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利用日常探测中探空出现的异常记录,分析得出在常规探测中探空仪信号突失、丢球、气球下沉或超升速等异常情况时,可及时运用L波段秒数据来判断温压湿3要素及测风数据的正确性,通过秒数据找出原因,进一步选取删除飞点、重新追踪目标、做部分资料缺测或重放球等处理方法;丢球时立即查询该次丢球前和前一时次该时间段的秒数据资料,迅速锁定目标,准确抓球,杜绝补放和重放球;遇气球下沉或升速异常时,查看下沉前后温压湿3要素秒数据,准确确定记录下沉段,并按L波段（1型）高空气象探测系统业务操作手册要求,在L波段（1型）高空气象探测系统处理软件中做删除下沉记录处理。 相似文献
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L波段雷达探测气球丢球是各探空站普遍存在的问题,也是大家都在着手解决的。结合多年的业务实践,分别对造成丢球的原因及对策作了较为详细的介绍,希望能给使用L波段雷达的各探空台站有所帮助。 相似文献
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L波段二次测风雷达-电子探空仪高空气象探测系统是新一代高空气象探测系统,其性能、操作方法、业务流程等与59-701探测系统有所不同。文章介绍了杭州高空站2002~2004年3年中使用新一代高空气象探测系统的一些使用技巧和故障处理方法。内容包括雷达检查、探空仪基测、电池浸泡、仪器装配、瞬间观测及数据输入、气球施放、旁瓣抓球判断、探测中途丢球、放球软件出现非正常现象等。 相似文献
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GFE-1型L波段雷达在跟踪〈3000m范围内的过顶球1／1标和当有源目标物的回波强度衰弱或回波频率超出于雷达接收机中心工作频率一次谐波以上时,雷达自动跟踪目标常常失败。通过分析探空气球低空过顶的气象条件,建立起低空过顶跟踪模式及该模式的应用方法,提出优化电池释放电量进程,降低回波强度衰减量与回波频率漂移量,探讨电池浸泡方法。提高新一代L波段雷达在探测过程中对探测目标的稳定跟踪,保证探测质量及探测资料的完整性、准确性,杜绝因低空丢球导致重放球事件的发生。 相似文献
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GFE-1型L波段雷达在跟踪<3 000m范围内的过顶目标和当有源目标物的回波强度衰弱或回波频率超出于雷达接收机中心工作频率一次谐波以上时,雷达自动跟踪目标常常失败。通过分析探空气球低空过顶的气象条件,建立起低空过顶跟踪模式及该模式的应用方法,提出优化电池释放电量进程降低回波强度衰减量与回波频率漂移量,据此探讨了电池浸泡方法。可提高新一代L波段雷达在探测过程中对探测目标的稳定跟踪水平,保证探测质量及探测资料的完整性、准确性,杜绝了因低空丢球导致重放球事件的发生,获得了良好的经济效益和质量效益。 相似文献
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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. 相似文献
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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. 相似文献
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由中国历史气候记录对季风导致唐朝灭亡说的质疑 总被引：1，自引：0，他引：1
张德二 《气候变化研究进展》2008,4(2):126-130
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. 相似文献
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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 相似文献
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Comparing the theoretical versions of the Beaufort scale, the T-Scale and the Fujita scale 总被引：1，自引：0，他引：1
G. Terence Meaden S. Kochev L. Kolendowicz A. Kosa-Kiss Izolda Marcinoniene Michalis Sioutas Heino Tooming John Tyrrell 《Atmospheric Research》2007,83(2-4):446-449
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. 相似文献
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准两年振荡对大气中微量气体分布的影响 总被引：11，自引：5，他引：6
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。 相似文献
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Chunguang CUI Wen ZHOU Hao YANG Xiaokang WANG Yi DENG Xiaofang WANG Guirong XU Jingyu WANG 《大气科学进展》2023,40(4):711-724
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... 相似文献
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流场配置及地形对西南低涡形成的动力作用 总被引：10，自引：8，他引：10
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. 相似文献