1996年黔南两次大范围强降水的对比分析

通过对１９９６年黔南６月１日与６月２０日两次大范围强降水天气过程的对比分析发现：６月１日强降水由８５０ｈＰａ低涡切变东南移造成，降水强度大，影响时间短，云团结构紧凑；６月２０日强降水由冷锋南移造成的，降水强度小，影响时间长，云团结构前紧后松，６月１日与６月２０日暴雨云团的发展区均是高能区，区别在于６月１日暴雨云团的生成比６月２０日暴雨云团的生成需要更多的不稳定能量。     

一次局地强降水的主要物理过程和特征分析

分析了１９９４年８月１日出现在青州市西南山区的一次局地强降水过程。研究了地形、大尺度天气背景以及中－β尺度系统对局地强降水的作用以及暴雨云团的一些特征，对山区局地大暴雨的预报有一定的参考价值。     

云南主汛期强降水过程年代际变化及其环流特征分析

应用云南1961～2000年共40a 1～12月的全省125个气象站逐日降水资料，统计了云南主汛期(6～8月)全省性强降水过程总次数，并分析了强降水过程的年代际变化及其环流特征。结果表明：1971年以前，云南主汛期处于强降水过程偏多的年代，1972年至1992年云南主汛期处于强降水过程相对偏少的年代，1992年之后，云南主汛期又转为强降水过程偏多时期。在云南主汛期强降水过程偏多和偏少时期，其环流特征存在明显的差异。     

一次强华北冷涡的分析

对１９９５年６月３０日－７月１日华北高空冷涡的强降水过程作了详细分析，探讨了冷锅演变的物理量场分布特征及其云系变化与降水的对应关系，为日常业务预报提供了一些启示。     

99.6.13青海东部强降水天气过程的分析

通过常规气象资料、卫星云图和Ｔ１０６数值预报产品中的要素场和物理量场资料,分析了青海东部地区１９９９年６月１３日夜间到１４日强降水天气过程,得出了一些预报强降水天气过程的依据。     

高原春季一次强雨（雪）天气过程的物理量诊断分析

通过对2002年4月3日20时至4日08时青海省东部农业区强降水天气过程的物理量诊断分析，揭示了高原春季产生强降水天气过程的动力和热力条件，确定了产生这次高原春季强降水的一些物理特征量，加深了对强降水天气发生、发展的认识。     

长江三峡枯水期出现区域性强降水的环流特征

该文以长江三峡地区６个站１９６１－１９９４年１０月－１月的逐日降水量来确定该地区发生区域性强降水的雨日，用同期的历史天气图分析产生区域性强降水的原因，影响系统和环流形势２，归纳出长江三峡地区产生区域性强降水的６类环流型，并进行逐日反查，概括出两类环流型产生区域性强降水的预报指标。     

辽宁省夏季强降水天气环流特征分析

由于强降水而引发的洪涝是辽宁的主要灾害之一，做好强降水预报是做好洪涝预报的基础。中期预报以其较长的时效性，愈来禽引起人们的重视。随着科学技术的发展，在3～6天中期预报时效内准确预报强降水已成为可能。据统计，在综合考虑全省平均及分片平均候累积降水量的前提下，1961-1994年夏季辽宁省共发生强降水过程43次、较强降水过程40次。强降水过程不同于干旱过程，强降水过程一般具有突发性和持续时间短的特点，发生较强降水或强降水过程往往决定于候内一次降水过程的强度和持续时间。     

长江三峡枯水期区域性强降水的一种重要天气形势

利用长江三峡地区６个站１９６１－１９９４年１０月－１月的逐日降水量确定该地区发生区域履强降水的雨日，结合同期的历史天气图分析该地区产生生强降水的原因，影响系统和环流形势特征，归纳出长江三峡地区产生区域性强降水的两槽一脊型环流型，并进行逐日反查，概括出两槽一脊环流型产生区域性强降水的前期预报指标。     

汛期强降水过程与月内低频降水的联系及其可能机制

利用1981 2010年中国753站逐日降水观测资料、NCEP/NCAR第二套逐日再分析资料及实况天气图等,选取长江中下游32次大范围持续性强降水过程,分析了该类强降水过程与月内(10~30天)低频降水的联系,并重点讨论了形成该类强降水过程的可能机制。结果表明:(1)长江中下游夏季降水具有显著的月内低频振荡周期。大范围持续性强降水过程基本位于降水低频振荡的峰值阶段。(2)梅汛期(6 7月)月内低频降水峰值位相前期,西太平洋副热带高压(下称西太副高)西伸北进,高低空急流发展加强。在强降水过程发生期,高中低层配置出现垂直方向上的最佳耦合;而台汛期(89月)低频降水峰值位相前期,西太副高东退南撤,低空急流逐渐南落至长江中下游东南部,与高空急流相配合,为强降水过程的发生提供了有利条件。(3)梅汛期东北亚低频位势高度低值区南下,与中纬太平洋西传的低频波列在长江中下游汇合。同时西太副高发展加强,造成了长江中下游降水峰值位相南高北低的低频位势高度分布,有利于强降水过程的发生;台汛期伴随从热带西太平洋到日本海低频波列的西北向移动,菲律宾东北部的低频气旋及其北侧低频反气旋的降水峰值位相分别移至长江中下游和东北亚地区,导致暖湿、干冷气流在长江流域交汇,进而造成强降水过程。(4)菲律宾以东洋面低频强对流可作为梅汛期和台汛期强降水过程发生的前期热带信号,提前低频降水峰值位相10天左右。     

控制论与人工影响天气 I: 人工增雨作业中的正反问题及最优调控

利用自然控制论的观点,重新审视了人工影响天气诸多方面的问题,提出了人工调控有限区域天气的正问题和反问题,并对最优调控问题,根据观测实例进行了分析讨论.结果表明,自然控制论是指导开展人工影响天气的一个好的理论框架,不仅要加强观测以了解自然降水过程,发展数值模式以更好的模拟实际降水过程,更需要开展反问题的研究;对最优调控的讨论表明,不能仅仅局限于有无催化可能,更应全面考虑降水云系的结构.     

Weather regimes over Senegal during the summer monsoon season using self-organizing maps and hierarchical ascendant classification. Part II: interannual time scale

The aim of this work is to define over the period 1979–2002 the main synoptic weather regimes relevant for understanding the daily variability of rainfall during the summer monsoon season over Senegal. “Interannual” synoptic weather regimes are defined by removing the influence of the mean 1979–2002 seasonal cycle. This is different from Part I where the seasonal evolution of each year was removed, then removing also the contribution of interannual variability. As in Part I, the self-organizing maps approach, a clustering methodology based on non-linear artificial neural network, is combined with a hierarchical ascendant classification to compute these regimes. Nine weather regimes are identified using the mean sea level pressure and 850?hPa wind field as variables. The composite circulation patterns of all these nine weather regimes are very consistent with the associated anomaly patterns of precipitable water, mid-troposphere vertical velocity and rainfall. They are also consistent with the distribution of rainfall extremes. These regimes have been then gathered into different groups. A first group of four regimes is included in an inner circuit and is characterized by a modulation of the semi-permanent trough located along the western coast of West Africa and an opposite modulation on the east. This circuit is important because it associates the two wettest and highly persistent weather regimes over Senegal with the driest and the most persistent one. One derivation of this circuit is highlighted, including the two driest regimes and the most persistent one, what can provide important dry sequences occurrence. An exit of this circuit is characterised by a filling of the Saharan heat low. An entry into the main circuit includes a southward location of the Saharan heat low followed by its deepening. The last weather regime is isolated from the other ones and it has no significant impact on Senegal. It is present in June and September, and missing in July and August, meaning that this is a weather regime more specific of the intermediate seasons than the summer. It is included in a large-scale pattern covering the northern latitudes of Europe. The correspondence between these “interannual” synoptic weather regimes and the “pure” synoptic regimes defined in Part I has been established. By selecting a high statistical significance level for these correspondences, each of five out of nine “interannual” weather regimes has a close correspondence with one “pure” synoptic weather regime, one out of them have links with two “pure” regimes, and the last three regimes have no significant correspondence in terms of “pure” regimes. However when considering more moderate links, two out of these three regimes show a connection with a “pure” regime, and the last one remains isolated. The ensemble of the weather regimes occurrences can explain a significant part of interannual variability of summer rainfall amount over Senegal, especially linked to the driest and the wettest weather regimes occurrences. It is also shown that Senegal rainfall state is very sensitive to a small displacement or deformation of the weather regime patterns.     

2003年 8月 21-22日辐合气流暴雨天气过程总结

本文综合应用天气图、静止卫星云图、物理量诊断场,分析了 2003年 8月 21～ 22日黑龙江省大范围强降水过程.分析了乌拉尔山阻高、副热带高压和冷暖空气在暴雨天气过程中的作用.得出有预报指示意义的特征.并对日本传真图的降水预报能力进行了检验分析.在暴雨预报中也具有一定的预报意义.     

Weather regimes over Senegal during the summer monsoon season using self-organizing maps and hierarchical ascendant classification. Part I: synoptic time scale

The aim of this work is to define over the period 1979?C2002 the main synoptic weather regimes relevant for understanding the daily variability of rainfall during the summer monsoon season over Senegal. ??Pure?? synoptic weather regimes are defined by removing the influence of seasonal and interannual time scales, in order to highlight the day by day variability of the atmospheric circulation. The Self-Organizing Maps (SOM) approach, a clustering methodology based on non-linear artificial neural network, is combined with a Hierarchical Ascendant Classification to compute these regimes. Nine weather regimes are identified using the mean sea level pressure and 850?hPa wind field as variables, and gathered into three classes. Two of these weather regimes represent the classical 3?C5-day African easterly waves with a mean wavelength of about 3,000?km. Three others are characterized by a modulation of the semi-permanent trough located along the western coast of West Africa and might be interpreted in terms of the 6?C9-day easterly waves. The last four weather regimes are characterized by a more or less strong north?Csouth dipole of circulation. They can be interpreted as a northward/southward displacement of the Saharan Heat Low for two of them, and a filling/deepening of this depression for the other two. The circulation patterns of all these nine weather regimes are very consistent with the associated anomaly patterns of precipitable water, mid-troposphere vertical velocity, outgoing longwave radiation, and finally rainfall. Rainfall distribution is also highlighted over the southwestern area of Senegal.     

Impacts of Climate Changes on Elk Population Dynamics in Rocky Mountain National Park, Colorado, U.S.A.

Changing climate may impact wildlife populations in national parks and conservation areas. We used logistic and non-linear matrix population models and 35 years of historic weather and population data to investigate the effects of climate on the population dynamics of elk in Rocky Mountain National Park (RMNP), Colorado, U.S.A. We then used climate scenarios derived from Hadley and Canadian Climate Center (CCC) global climate models to project the potential impact of future climate on the elk population. All models revealed density-dependent effects of population size on growth rates. The best approximating logistic population model suggested that high levels of summer precipitation accelerated elk population growth, but higher summer minimum temperatures slowed growth. The best approximating non-linear matrix model indicated that high mean winter minimum temperatures enhanced recruitment of juveniles, while high summer precipitation enhanced the survival of calves. Warmer winters and wetter summers predicted by the Hadley Model could increase the equilibrium population size of elk by about 100%. Warmer winters and drier summers predicted by the CCC Model couldraise the equilibrium population size of elk by about 50%. Managers of national parks have relied on effects of weather, particularly severe winters, to regulate populations of native ungulates and prevent harmful effects of overabundance. Our results suggest that these regulating effects of severe winter weather may weaken if climate changes occur as those that are widely predicted in most climate change scenarios.     

台风西北侧强对流天气浅析

台前强对流天气过程是较为罕见的.本文通过计算华南地区12站的物理参数以及分析天气形势,并结合台风结构来寻求强对流产生的内外因素.以便为日后的台前天气预报工作服务.     

柯坪地区1971-2008年沙尘天气特征分析

利用1971—2008年柯坪站的地面气象资料及周边气象站的气候整编资料,分析了该地区的沙尘天气变化特征。结果表明:该地区沙尘天气以浮尘为主,扬沙次之,沙尘暴最少;具有明显的季节变化和年际变化,每年3—9月是沙尘天气的多发时段;浮尘年日数近38 a来无明显变化,沙尘暴和扬沙日数呈明显减少趋势;沙尘天气总体分布自东向西逐渐增多。沙尘天气与当地降水量和大风的关系密切,降水偏多的年份,沙尘天气偏少,在吹偏西北风时易出现沙尘天气。     

Personal harm and support for climate change mitigation policies: Evidence from 10 U.S. communities impacted by extreme weather

A growing body of research examines the role of extreme weather experience—as one of the most personal, visceral (and increasingly frequent and severe) impacts of climate change—in shaping views on climate change. A remaining question is whether the experience of an extreme weather event increases climate change concern via experiential learning or reinforces existing views via motivated reasoning. Building on this work, we explore the relationship between personal experience and climate change policy preferences using surveys in 10 communities that experienced extreme weather events (3 tornadoes, 3 floods, 2 wildfires, 1 hurricane and 1 landslide). We find that self-reported personal harm aligns with objective measures of event impacts and that personal harm (i.e., experience) is associated with higher levels of policy support. However, we do not find that objective measures of event impacts are related to policy support. Though political ideology (i.e., motivated reasoning) dominates our model of policy support in predictable ways, personal harm moderates this relationship suggesting that conservatives reporting higher levels of personal harm from the event are, on average, more likely to express support for climate policy than those reporting lower levels of harm. We postulate that while extreme weather events may serve as teachable moments on climate change, their lessons may only reach conservatives who feel personally harmed, even in the communities most affected.     

改进气象雷达TITAN算法在灾害性天气预警中的应用研究

提出一种适用于我国不同季节、经纬度和下垫面的改进气象雷达TITAN算法。建立天气雷达数据格式转换系统,将我国不同型号新一代天气雷达基数据转换成MDV格式雷达数据;按我国不同气候类型、经纬度和海陆下垫面特征,统计获取不同区域强风暴天气雷达特征指标参数阈值。利用云贵高原和海南地区不同下垫面的两次典型超级单体强风暴天气雷达实况数据与改进的TITAN算法进行实验对比分析。分析结果指出,采用改进TITAN算法识别、跟踪和预测0.5~1 h后的强风暴天气误差较小,可信度较高,有助于识别预警灾害性天气和人影指挥作业。     

1961—2008年银川市灰霾天气的气候特征

对1961—2008年银川市灰霾天气日数资料进行分析。结果表明：银川市灰霾天气呈逐渐增加的趋势2,0世纪80年代前为缓慢增加阶段,20世纪后灰霾天气显著增加2,000年后灰霾天气急剧增加。银川市灰霾日数最多为12月,其次为11月,最少为5月,呈现出冬季大于秋季大于春季大于夏季的季节特征。一般情况下,银川市灰霾日数持续1—3d,持续2d及以上的灰霾天气占17%,持续5d及以上的灰霾天气占1%。持续时间较长的灰霾天气集中出现在冬季11月至翌年2月。灰霾天气持续时间与年代际变化有关,2000年前,银川未出现持续5d以上的灰霾天气过程;2000年后,随着灰霾天气日数增多,灰霾持续时间延长。