利用卫星气象信息提高地面测站测报质量

气象卫星ＭＩＣＡＰＳ系统为基层台站提供了内容广泛的气象信息。这不仅提高了基层站台的预报业务水平 ,还给地面观测业务的提高带来帮助。测报员通过对卫星云图、高空图、地面图的了解 ,及时掌握影响测站或即将影响本站的天气系统 ,为值班期间的正确测报做好准备。在夜间测报时 ,遇有云层布满全部天空 ,无法根据《地面气象观测规范》中有关夜间测云方法进行测云时 ,还可以参考靠近观测正点时间的红外云图来帮助观测员判断天空云状及云高。1　利用天气图提前了解影响本站的天气系统 ,为正点观测编报做好技术准备在测报员接班前或观测前 ,调…     

地面测报中如何避免观测及发报错误

地面测报是一项基础气象业务。它的主要任务是观测、发报和编制报表。地面测报中的查算、编报、报表制作以及预审等，均由计算机来完成，从而大大地避免了过去由于手工操作而出现的人为错误。现在，通过人机结合，在观测过程中只要不犯技术性错误，正确读取仪器的刻度，正确编报云、天电码，就能避免观测、发报错情。至于如何避免错情，根据作者10多年测报经验，有以下体会。（1）对云、天电码及其技术说明、编码原则要非常熟悉。（2）遇复杂天气，观测前就要对所要编报的天气电码做到心中有数，避免临时由于考虑不周而造成错误。要注意，天…     

测报时间概念混淆的问题

通过学习和比较业务规范与指导文件,参考相关学术论文,并结合地面气象测报工作经验,发现在测报业务上存在对“时段”和“时刻”两个概念混淆的情况,以至影响天气现象起止时间的记录和编报不统一。原因是部分测报工作者曲解了《地面气象观测规范》和《地面气象电码手册》的某些表述,使用“自创”的时间概念去指导天气现象出现时间的记录和编报。进而指出在时间的表示与解释、时间误差处理、探测自动化编程等方面厘清“时段”和“时刻”概念的必要性和方法,并提出了对测报业务及管理的改进建议。     

浅谈天气现象7WWW_1W_2的编报

以下是本人对天气现象编码的一些观点和看法，现提出来与广大测报人员共同探讨。1通过WWW1W2的编码，比较完整地反映出某测站现在和过去天气时段内出现的各种天气现象。1．1WWW1W2编码规定的原则精神是：优先考虑最接近观测正点的天气现象。从现在天气现象WW电码表中可以看出，一般情况下观测时15分钟时段内出现的天气现象WW编码要比观测前1小时时段内出现的天气现象WW编码大，WW编码17、18、19、28、29作为特殊规定除外。1．2当有几种天气现象存在时，优先考虑最重要的天气现象。一般而言电码大所指示的天气现象要比电码小所指示的…     

地面测报中编报与正式记录的不一致

地面测报工作中，编发的气象报告应真实地反映测站天气实况，与气簿中的正式记录相一致。但若按正常观测程序观测后，在正点前又出现更重要的天气现象，则应进行补测改报(一般指云、能见度、天气现象项目)，补测记录记人值班日记中，气簿—1中的原始正式记录不能更改。如：某站某日14时气簿—1中能见度纪录为3．0km，原有扬沙。13：56扬沙发展成沙尘暴，能见度降至0．5km。此时能见度、天气现象均须补测改报。     

天气现象的合并选码

天气报观测时15分钟内、航空报观测时10分钟内出现的现象都是“观测时的现象”.当观测时先后或同时出现两种或以上天气现象时,应合并选码. 雨或毛毛雨并有雨淞生成和雾并有雾淞生成时,现在天气电码的选择,可以说是合并选码,也可以说是按大码编报原则.因为雨、毛毛雨、雾都有单独编报的电码,而雨淞、雾淞却没有相应的电码,但编报电码中有雨或毛毛雨并有雨淞结成和雾并有雾淞生成的电码,且电码较雨或毛毛雨、雾单独     

十二字编码程序——浅谈7wwW_1W_2的编报

在新的地面天气电码中,与旧电码比变动较大的是7wwW_1W_2组,它不但增加了一个W,而且提出了几个新的概念,初略地看,似乎难以掌握,但通过反复学习,只要领会好雷暴期间和雷暴停止后的降水等新的概念,按照天气现象出现及持续时间的编报规定,就可以用四句话,十二个字来归纳7wwW_1W_2的编报程序,既快、又准,四句话是:“选现在,列种类,去对应,定1、2”共十二个字。 “选现在”选现在天气现象电码。 “列种类”列出整个过去天气时段所出现的天气现象种类。 “去对应”去掉现在天气电码所对应的过去天气现象。     

浅议GD-01Ⅲ天气电码中W1W2和WW的编报

对地面气象测报业务技术规范和规定中容易产生模糊或理解错误的概念进行了阐述，对过去天气现象和现在天气现象的配合编报原则、常见错误及其正确编报进行较详细地说明。     

贵州省普安县一次暴雨天气过程初步分析

2006—06—12—06—13普安县出现大范围的降水天气过程,通过对高空图、地面图、卫星云图和雷达回波的分析,判断该次大型降水天气过程是高空槽和低涡切变共同影响,触发普安县不稳定能量造成的,是一次典型的暴雨天气过程。     

雾的误区

在市局组织的测报复评中发现 ,有的站在雾的记录与发报中存在一些模糊认识和误区。其一 ,能见度 <1ｋｍ有雾时 ,天气加密报中现在天气现象电码应从 42～ 49中选择。有的站只要观测时有雾 (有其他天气现象时除外 ) ,现在天气现象电码就固定编报 42。但如云量纪录为 1 0 / 1 0 ,云状栏记雾 ,现在天气现象电码仍编为 42 ,显然电码反映的天空状况(电码 42反映天空可辨明 )与实际天空状况 (完全不可辨 )不一样。其二 ,有的站能见度记 0 .0ｋｍ ,而云量记为 0 / 0 ,即天空完全可辨 ,这种情况极为少见。出现这种情况可能是观测员对雾的记录判断存在…     

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...