2009年夏季铜仁地区高温干旱的诊断分析

2009-07—09铜仁地区出现了大范围持续性的高温干旱天气,给铜仁地区农业生产和人民生活带来较大的影响。该文对此次高温干旱的成因从环流形势、物理量场进行诊断分析。     

2009—2010年特大干旱特点及影响评估

利用铜仁地区10个气象台站1961年至2010年4月的月和旬降水资料,对2009—2010年夏秋连旱、冬春连旱的持续时间、范围、强度与历史同期进行对比分析,对农业生产的危害和人民生活的影响进行了评估,同时分析了自然地理、生态环境对干旱的影响。分析结果表明,2009年7月—2010年4月,铜仁地区降水较常年同期偏少12.7%~51.7%,出现了严重的夏秋连旱叠加冬春连旱,受旱范围和干旱强度双双突破了该区气象历史记录。干旱严重影响到农作物生长、人畜饮水、水力发电、城镇供水及森林防火等,尤以人畜饮水问题最为突出;但是良好的生态环境能延缓灾情加重的趋势。     

气象条件对水利建设影响分析与对策思考

利用铜仁地区10个常规气象站近40 a历史基本资料并结合梵净山区17个雨量观测站10 a观测资料,分析了铜仁地区气候特点以及水利工程建设、安全运行、管理与气象条件的相关关系,针对当前气象保障水利工程建设及运行安全存在的不足,提出水利建设气象保障措施对策建议,为铜仁地区水利建设的规划编制提供科学依据。     

用逐步判别分析方法作铜仁地区夏旱的长期预报

利用1959-1998年北半球500hPa、100hPa高度、北太平洋海温等网格点资料以及本区地面气象要素等资料,应用具有引进和剔出因子双重功能的逐步判别方法,建立了铜仁地区关于夏旱和夏季降水3个预报对象的判别方程.结果表明,该方法的历史拟合率和独立试报都较理想.     

铜仁地区夏旱的100hPa环流异常特征分析

铜仁地区是贵州省夏旱最严重的地区之一 ,本文按铜仁地区夏旱出现的先后区分出洗手干 ( 6月 )和伏旱 ( 7～ 8月 )两类夏旱天气 ,并据此分别对两类夏旱的 10 0hPa环流异常特征作了较为深入的讨论 ,以进一步揭示形成我区夏旱的大气环流演变规律。     

铜仁地区实时气象业务系统设计及其应用(摘要)

本文较全面地介绍了铜仁地区实时气象业务系统（TRSSXT）的设计思路、系统构成、建设进展及其应用情况。分述如下:1 TRSSXT 设计思路 结合铜仁地区气象部门自身实际,使TRSSXT建设与国家9210工程相衔接,着力改善通讯条件,提高地区台接收和处理信息的能力,共享省台系统信息资源,逐步取消传统的无线收报、填图和传真业务,形成一个配套、快速、有效的综合网络化气象业务系统。     

铜仁地区强对流天气的成因及临近预报

铜仁地区位于贵州东北部，处于亚热带显著的季风区。每年春夏，由于特殊的地形作用，气流无论从偏东还是偏西方向进入，均会在中部偏西部或偏东产生明显的气流辐合区，辐合区的D、ζ十分有利于上升运动。中小尺度系统移人后，与地形辐合叠加，形成黔东北地区强烈的对流天气。通过对15个强对流天气个例进行分析和探索，归纳出铜仁地区强对流天气的背景，并建立强对流产生和移动路径的临近预报模式，对提高铜仁地区的强对流天气预测预警能力，尤其是冰雹落区的临近预报，具有十分重要的价值。     

铜仁地区夏早的100hPa环流异常特征分析

铜仁地区是贵州省夏旱最严重的地区之一,本文按铜仁地区夏旱出现的先后区分出洗后干（６月）和伏旱（７～８月）两类夏天气,并据此分别对两类夏旱的１００ｈＰａ环流异常特征作为较为深入的讨论,以进一步揭示形成我区夏旱的大气环流演变规律。     

2009年铜仁地区高温干旱特征及成因诊断分析

利用1961-2009年铜仁地区10个县站逐日降水量资料、最高气温和平均气温资料,以及NCEP 2.5°×2.5°再分析资料,诊断分析了2009年7月10日～9月9日高温干旱的环流形势和物理量场,结果表明：（1）西太平洋副热带高压较常年异常偏强、偏西和南亚高压中心偏西、东伸偏强,是这次铜仁地区高温干旱发生的主要原因。（...     

贵州铜仁地区一次罕见大范围冰雹过程分析

利用常规观测、地面加密自动站降水、雷达观测及NCEP/NCAR再分析资料,对2016年4月2日发生在贵州省铜仁市多个县(区)的一次大范围冰雹天气过程进行分析。结果表明:(1)此次大范围冰雹过程发生在中高层低涡槽后西北冷空气与低层西南暖湿气流叠加的不稳定层结中;强垂直风切变及低层辐合高层辐散有利于对流风暴的发展和维持;(2)中高层干冷空气和边界层弱冷空气入侵是激发强对流产生的有利条件;(3)当铜仁地区地面至400 hPa垂直风切变超过8×10~(-3)s~(-1)时,有利于大范围冰雹系统发展;(4)多个对流单体有组织地形成弓形回波,且强回波伸展至-20℃层高度之上;有界弱回波区、悬垂回波、三体散射现象表征了冰雹产生的典型特征;降雹点50dBZ以上的强回波顶高在8.1~9.8 km之间,VIL在38.4~66.8 kg·m~(-2)之间,这些可作为铜仁地区产生冰雹的重要指标。     

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.     

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.     

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     

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。     

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...     

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.