全国大部气温偏高 中东部大雾频繁——2007年2月——

2月，冷空气活动偏弱，全国大部气温比常年同期偏高，19个省（市、区）的月平均气温创下1951年以来历史同期最高纪录；全国平均降水量较常年同期略偏多，华北东部、西北东部、川渝等地的部分地区旱情持续或发展；中东部地区频繁出现大雾天气；云南、黑龙江、新疆等地的部分或局部地区遭受雪灾和低温冷冻灾害；南方部分地区出现持续阴雨天气；辽宁、内蒙古、新疆等地的部分地区遭受沙尘和大风天气袭击。     

南方持续低温阴雨雪部分地区遭严重冻害

2月份,全国大部地区降水量较常年同期偏多,南方部分地区出现持续低温阴雨雪寡照天气;江南及福建等局部出现暴雨及山体滑坡等灾害;滇、新等地局部发生雪灾;华南中南部、云南南部持续少雨雪,旱情持续或发展.月平均气温,全国大部地区较常年同期偏低,湘、鄂、黔等地的部分地区遭受严重冰冻灾害.     

强台风韦帕登陆浙江滇桂局地遭暴雨洪涝—2007年9月—

9月,全国平均气温为16.8℃,较常年同期(16.0℃)偏高0.8℃.北京9月区域平均气温为1951年以来历史同期最高;河北、内蒙古、辽宁为次高;吉林为第三高;贵州为第三低.全国平均降水量为67.9mm,接近常年同期(66.2mm).月内,强台风韦帕登陆浙江,浙苏闽鲁等地受灾;东北西部及内蒙古东部干旱持续发展;云南、广西等地遭受局地暴雨洪涝灾害;北方部分地区遭受初霜冻灾害;南方部分地区出现低温阴雨天气.     

全国气温偏低南方冻害严重

2005年2月份,全国大部分地区降水量较常年同期偏多,南方部分地区出现了长时间的持续低温阴雨雪天气,湖南、湖北、贵州省的部分地区遭受了严重的冰冻灾害;江南及福建等局部地区出现暴雨及山体滑坡等灾害;云南、新疆等地的局部发生雪灾;华南中南部、云南南部持续少雨雪,旱情持续或发展.全国大部分地区的月平均气温较常年同期偏低.     

每月天气-2001年5月 北方高温少雨旱情严重南方降雨频繁局地洪涝

5月份,全国大部地区降水偏少,华北、黄淮等地旱情严重;南方局部地区出现暴雨洪涝.全国大部地区月平均气温接近常年或偏高,华北、黄淮、江淮等地明显偏高,部分地区中下旬出现持续高温天气.北方多大风沙尘天气,内蒙古、新疆等地的局部地区遭受强沙尘暴袭击.     

气温走高刷新纪录大风肆虐吹翻列车

2月,全国平均气温为0.7℃,比常年同期偏高3.5℃,为1951年以来历史同期最高值。全国平均降水量为18.0mm,较常年同期略偏多。月内,我国大部地区气温明显偏高,19个省(市、区)的月平均气温为1951年以来历史同期最高值;华北东部、西北东部、川渝等地的部分地区旱情持续或发展;我国中东部地区出现大雾天气,给春运交通带来不利影响;云南、黑龙江、新疆等地的部分或局部地区遭受雪灾和低温冷冻灾害;南方部分地区出现持续阴雨天气;辽宁、内蒙古、新疆等地的部分地区遭受沙尘和大风天气袭击。1我国大部气温明显偏高,部分地区气温创1951年以来历史同期…     

北方部分地区干旱严重 两个热带风暴登陆广东

９月份,全国普遍偏暖,大部地区光照充足;但降水偏少,北方部分地区干旱严重,南方局地存在不同程度的旱情。上半月,淮河以南地区出现高温酷热天气。下半月,东北中北部等地遭受早霜冻袭击,江南中南部等地的部分地区遭受轻度寒露风危害。而且,有两个热带风暴登陆我国。总体来看,气候条件对农作物生长有利。１北方部分地区干旱严重本月,全国大部分地区月降水量一般有５０～１００ｍｍ,华南东部、云南大部、四）１１盆地西部及江西的部分地区达１００～３００ｍｍ;华北北部和黄淮大部有５０～１５０ｍｍ,北方其余大部地区少于５０ｍ…     

四川淮河流域暴雨成灾台风登陆浙闽损失严重--2005年7月--

7月份,全国平均月降水量比常年同期偏少.但淮河流域及四川等地的部分地区降水明显偏多,遭受暴雨洪涝或泥石流、滑坡等地质灾害;西北东北部及内蒙古中西部、湖南等地旱情持续.全国月平均气温较常年同期偏高.江南、华南等地多高温酷热天气;局地强对流天气发生频繁,内蒙古、山东等地受灾较重;甘肃中西部、内蒙古西部的部分地区出现强沙尘暴天气.月内有5个热带气旋生成,其中台风"海棠"和强热带风暴"天鹰"在我国登陆,受台风"海棠"影响浙、闽损失严重.     

大部地区降水偏少 部分地区出现旱象 江南低温阴雨寡照 影响作物生长收获——2001年8月

8月份 ,我国大部地区降水偏少 ,且分布不均 ,华北、东北西部、黄淮西部、江汉、西南东部等地部分地区仍有旱象 ;江苏、云南等省部分地区出现暴雨、大暴雨或特大暴雨 ,局部洪涝灾害严重 ;山东、河北等省局部遭受雷雨大风、冰雹等强对流天气袭击 ,造成一定经济损失。黄淮、江淮、江南、西南地区东部等地月平均气温稍偏低 ,日照时数偏少 ,阴雨日数多 ,尤其是江南及川东、重庆等地低温阴雨寡照明显 ,给农作物、经济作物及大春作物的收获等带来不利影响。月末 ,有一个热带风暴在广西北海登陆 ,海南、广东等省遭受损失。1　北方部分地区及江淮西部…     

全国部分地区发生暴雨洪涝 江南东部等地出现持续高温——2004年7月

7月份 ,全国大部地区降水接近常年同期或偏多 ,湖南、湖北、河南、广西、云南等地的部分地区发生较为严重的暴雨洪涝或泥石流、滑坡等灾害 ;东北西部及内蒙古东北部旱情缓和 ,江南东部、江淮等地的部分地区出现伏旱。全国大部月平均气温和月日照时数接近常年同期。江南东部、江淮等地出现持续高温天气 ;河北、山西、广东、安徽等地的局部遭受风雹、雷暴等强对流天气袭击 ;月内有 3个热带风暴 (或强热带风暴 )登陆我国。总体上讲 ,7月的气候条件对农业生产基本有利。1　湘鄂豫桂部分地区遭受暴雨洪涝灾害月降水量 ,东北东部和南部、华北大部…     

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.     

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...     

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.     

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.