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通过广西气象通信技术发展回顾,体会了气象通信在气象部门占据基础的和关键的地位,对广西气象通信今后的发展趋势进行展望。 相似文献
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20世纪80和90年代华北干旱特征及成因分析 总被引:5,自引:2,他引:5
在全球气候变暖背景下,20世纪80年代和90年代几乎有一半的年份出现干旱,90年代华北的干旱频率比80年代更高。本文从干旱基本状况、干旱强度和干旱空间分布出发,对华北地区这两个年代的干旱进行了比较,并从对全球气候变暖的响应和大气环流场特征等方面,探讨了这两个年代干旱的成因。研究表明,在干旱强度和空间分布上,90年代明显强于80年代。对全球气候变暖的响应90年代明显强于80年代,表现了更显著的增暖趋势。80年代的干旱年中北极涛动显著增强,中高纬度地区为气压正距平带控制;90年代的干旱年中北半球中高纬度地区为正负距平波列相间分布,存在EU和PNA遥相关型。本文还定义了西伯利亚高压指数,该指数90年代显著高于80年代,且与华北地区降水显著相关,可以作为华北地区旱涝预测的指标。 相似文献
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1建设项目概述《伊犁重大气象灾害预报服务体系》建设项目主要包括:地面和高空气象资料实时查询系统;历史资料及天气图查询系统;Micaps二次开发业务系统;城市概率预报系统;地县预报服务网络系统;重大气象灾害预报决策服务系统;重大气象灾害情报收集服务系统。2系统总体功能《伊犁重大气象灾害预报服务体系》的建设,优化和完善了现有预报、服务手段,将重大气象灾害预报服务体系包含的各分系统进行整合,建立伊犁重大气象灾害预报服务业务平台,提高现有预报、服务业务系统的总体功能,进一步发挥气象现代化建设在预报服务领域的综合效益。3各分… 相似文献
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利用1979—2009年JRA-25和NCEP/NCAR再分析资料,通过复矢量经验正交方法揭示了东亚地区夏季850 hPa风场变率的优势模态。结果表明:两套再分析资料所揭示的东亚夏季风在20世纪90年代初均发生了年代际转型,与我国夏季降水的年代际转型时间一致。伴随着东亚夏季风的年代际转型,我国北方大部分地区夏季降水减少,尤其是我国东北北部和长江、黄河之间105°E附近区域显著减少,而华南地区和淮河流域降水显著增加。从动力上解释我国夏季降水年代际转型特征,夏季500 hPa高度场两个时段 (1993—2009年和1979—1992年) 的差值分布显示为欧亚大陆北部准纬向遥相关波列,夏季850 hPa风场差值分布表现为贝加尔湖东南侧和日本以南地区存在两个异常反气旋式环流,而我国南方地区和鄂霍次克海附近均为异常气旋式环流。夏季西北太平洋、北印度洋以及部分中高纬度海洋的海温和春季欧亚大陆积雪在20世纪90年代初出现显著变化,春季北极海冰的年代际转型发生在20世纪90年代初,都可能成为东亚夏季风年代际转型的原因。 相似文献
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20世纪90年代以来东北暴雨过程特征分析 总被引:7,自引:2,他引:5
使用1990~2005年全国730站日降水资料和NCEP格点分析资料对1990~2005年东北地区大暴雨过程进行了分类研究,探讨21世纪前后夏季东北暴雨的主要特征.按照东北地区日降雨量大于50 mm的站点数不少于5个的标准,统计出1990~2005年东北地区的69个暴雨个例(共90天).在统计的基础上,进一步对造成大范围暴雨过程的天气形势进行分类研究.考虑阻塞高压、热带、副热带系统和西风带之间的相互关系,将暴雨过程的主要影响系统大致分为6类:(1)台风与西风带系统(西风槽、东北低涡)的远距离相互作用(20个,28.9%);(2)登陆台风(或南来低涡)北上与西风带系统(西风槽、东北低涡)相互作用(16个,23.2%);(3)台风直接暴雨(1个,1.5%);(4)低槽冷锋暴雨(16个,23.2%);(5)低空切变型暴雨(2个,2.9%);(6)东北低涡暴雨(14个,20.3%).在所有个例中与台风有关的共有37个,超过一半,占总数53.6%.台风的远距离水汽输送或登陆台风北上与西风带系统相互作用是东北地区产生大暴雨或持续性大暴雨的重要环流条件.此外,东北低涡和西风槽前系统造成暴雨个例也比较多,也是东北地区大范围暴雨的重要影响系统,低槽冷锋暴雨和东北低涡暴雨也各分为4小类.低空切变暴雨的切变线一般在低层较为明显.上述分析表明,夏季东北地区暴雨过程种类繁多,情况较为复杂,且进入新世纪以来该区降雨过程较为活跃,值得深入研究. 相似文献
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使用一个动力海洋与统计大气耦合的热带太平洋模式,对20世纪90年代的厄尔尼诺事件进行了数值模拟和预报.结果表明,模式能较好地再现3次暖事件的发展和演化过程,也能模拟1995/1996年的冷海温过程.预报试验的结果指出,20世纪90年代发生的厄尔尼诺事件具有其特殊性,很难在发展阶段作出准确预报,而一旦形成后,模式仍可对这类事件的成熟位相阶段作出大致提前6个月的有效预报.文中还用该模式对1997年的热带太平洋海表温度作了预报试验,预测1997年年底可能发生一次新的厄尔尼诺事件.关键词:20世纪90年代厄尔尼诺,简单海气耦合模式,预报试验. 相似文献
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Weakening of Interannual Variability in the Summer East Asian Upper-tropospheric Westerly Jet since the Mid-1990s 总被引:3,自引:1,他引:3
In this study,we found that the intensity of interannual variability in the summer upper-tropospheric zonal wind has significantly weakened over Northeast Asia and the subtropical western North Pacific(WNP) since the mid-1990s,concurrent with the previously documented decrease of the westerly jet over North China and Northwest China.Corresponding to this weakening of zonal wind variability,the meridional displacement of the East Asian westerly jet(EAJ) manifested as the leading mode of zonal wind variability over the WNP and East Asia(WNP-EA) before the mid-1990s but not afterward.The energetics of the anomalous pattern associated with the meridional displacement of the EAJ suggests that barotropic energy conversion,from basic flow to anomalous patterns,has led to the weakening of the variability in the EAJ meridional displacement and to a change in the leading dominant mode since the mid-1990s.The barotropic energy conversion efficiently maintained the anomalies associated with the variability in the EAJ meridional displacement during 1979-1993 but acted to dampen the anomalies during 1994-2008.A further investigation of the energetics suggests that the difference in the patterns of the circulation anomaly associated with either the first leading mode or the meridional displacement of the EAJ,i.e.,a southwest-northeast tilted pattern during 1979-1993 and a zonally oriented pattern during 1994-2008,has contributed greatly to the change in barotropic energy conversion. 相似文献
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This study investigated the drivers and physical processes for the abrupt decadal summer surface warming and increases in hot temperature extremes that occurred over Northeast Asia in the mid-1990 s. Observations indicate an abrupt increase in summer mean surface air temperature(SAT) over Northeast Asia since the mid-1990 s. Accompanying this abrupt surface warming, significant changes in some temperature extremes, characterized by increases in summer mean daily maximum temperature(Tmax), daily minimum temperature(Tmin), annual hottest day temperature(TXx), and annual warmest night temperature(TNx) were observed. There were also increases in the frequency of summer days(SU) and tropical nights(TR).Atmospheric general circulation model experiments forced by changes in sea surface temperature(SST)/ sea ice extent(SIE),anthropogenic greenhouse gas(GHG) concentrations, and anthropogenic aerosol(AA) forcing, relative to the period 1964–93, reproduced the general patterns of observed summer mean SAT changes and associated changes in temperature extremes,although the abrupt decrease in precipitation since the mid-1990 s was not simulated. Additional model experiments with different forcings indicated that changes in SST/SIE explained 76% of the area-averaged summer mean surface warming signal over Northeast Asia, while the direct impact of changes in GHG and AA explained the remaining 24% of the surface warming signal. Analysis of physical processes indicated that the direct impact of the changes in AA(through aerosol–radiation and aerosol–cloud interactions), mainly related to the reduction of AA precursor emissions over Europe, played a dominant role in the increase in TXx and a similarly important role as SST/SIE changes in the increase in the frequency of SU over Northeast Asia via AA-induced coupled atmosphere–land surface and cloud feedbacks, rather than through a direct impact of AA changes on cloud condensation nuclei. The modelling results also imply that the abrupt summer surface warming and increases in hot temperature extremes over Northeast Asia since the mid-1990 s will probably sustain in the next few decades as GHG concentrations continue to increase and AA precursor emissions over both North America and Europe continue to decrease. 相似文献
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根据切花植物和盆栽花卉对气象条件的要求 ,提出了合理利用广西气候资源 ,加速发展花卉生产的意见 ,为建设具有广西特色的花卉产业提供科学依据 相似文献
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The Walker circulation is one of the major components of the large-scale tropical atmospheric circulation and variations in its strength are critical to equatorial Pacific Ocean circulation.It has been argued in the literature that during the 20th century the Walker circulation weakened,and that this weakening was attributable to anthropogenic climate change.By using updated observations,we show that there has been a rapid interdecadal enhancement of the Walker circulation since the late 1990s.Associated with this enhancement is enhanced precipitation in the tropical western Pacific,anomalous westerlies in the upper troposphere,descent in the central and eastern tropical Pacific,and anomalous surface easterlies in the western and central tropical Pacific.The characteristics of associated oceanic changes are a strengthened thermocline slope and an enhanced zonal SST gradient across the tropical Pacific.Many characteristics of these changes are similar to those associated with the mid-1970s climate shift with an opposite sign.We also show that the interdecadal variability of the Walker circulation in the tropical Pacific is inversely correlated to the interdecadal variability of the zonal circulation in the tropical Atlantic.An enhancement of the Walker circulation in the tropical Pacific is associated with a weakening zonal circulation in the tropical Atlantic and vise versa,implying an inter-Atlantic-Pacific connection of the zonal overturning circulation variation.Whether these recent changes will be sustained is not yet clear,but our research highlights the importance of understanding the interdecadal variability,as well as the long-term trends,that influence tropical circulation. 相似文献
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大旅游时代广西旅游气象服务发展对策探讨 总被引:1,自引:0,他引:1
旅游业是高度依赖自然环境和气象条件的产业,气象条件是影响旅游质量和旅游安全的重要因素,我国将"十三五"旅游业发展规划纳入国家重点专项规划,表明我国已步入了"大旅游"时代,旅游业对气象服务的需求愈加迫切。本文分析了广西旅游业对气象服务的需求、旅游气象服务的现状和存在的问题,研究结果表明:广西旅游业在构建旅游安全保障体系、旅游特色挖掘与打造、旅游大数据平台产品开发等方面对气象服务有迫切的需求;广西已开发了部分旅游气象服务产品,并在部分景区布设了气象观测设施,为开展景区旅游气象服务打下了基础;广西在旅游气象两部门常态化合作、旅游气象服务综合观测网建立、旅游气象服务产品开发和市场推广、旅游气象信息发布等方面还不能满足公众的需求。最后,研究提出了促进旅游气象服务发展的建议和对策。 相似文献
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《气象研究与应用》2015,(2)
通过利用石漠化区29个县的1961~2010a降水观测资料,分析近50a来石漠化区干旱和洪涝特征及灾害影响;在分析自然条件、社会状况和石漠化现状的基础上,提出旱涝灾害防御对策。结果表明,广西典型石漠化地区春旱、冬旱发生频率自西向东递减,夏旱、秋旱频率东部大、西部小;洪涝多出现在6~8月;洪涝频率高值区分布在桂东北山区和桂西山区。对广西典型石漠化区旱涝灾害的治理,可根据典型石漠化区自然条件和旱涝灾害分布特征,采取对岩溶石山型(峰丛洼地区)区和岩溶峰林型(平原与谷地区)区分区治理的方式,通过水利工程建设措施和生态环境措施提高石漠化区旱涝防范能力,减缓石漠化进程。 相似文献
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2006年广西气象培训班学员满意度调查与分析 总被引:1,自引:0,他引:1
根据2006年广西气象培训中心承办的14期气象培训班的学员满意度问卷调查数据,详细统计分析了学员对培训效果等11项调查内容的评价情况。结果表明,各培训班学员对培训效果表示满意或基本满意的比率在96%以上,远远高于目标考核要求的70%,培训效果比较好。学员对住宿及用餐等后勤保障工作的满意或基本满意率也高于70%,但有一定比例的学员对后勤保障工作不满意,并就如何改进气象培训工作提出了多项设想与建议。 相似文献