共查询到20条相似文献,搜索用时 593 毫秒
1.
登陆台风路径与降水分析 总被引:1,自引:0,他引:1
首先利用1979—2002年台风年鉴上的热带气旋纪要表进行分析,总结热带气旋的登陆数据,并根据热带气旋路径图归纳出线性、左折、右折三种路径的登陆热带气旋。利用欧洲中心每天4次(6小时预报)的总降水资料,将热带气旋作为一个整体来研究探讨它在海洋和陆地上的降水分布和演变特征,尤其是台风路径与降水分布之间的关系,弥补以往对热带气旋降水的研究只局限于陆地降水的不足。 相似文献
2.
热带气旋与台风气候变化研究进展 总被引:1,自引:0,他引:1
近年来,引起严重灾害的热带气旋和台风气候变化研究均有新的进展:近60年观测资料比对表明,由于海上观测手段不足,造成前期资料可靠性较低,近30~40年资料较为可靠,观测资料的可靠性随热带气旋强度的增强而增加;全球6个洋区观测资料计算分析显示,热带气旋存在多年代际变率,约自1970年以来,强和超强热带气旋活动有增强趋势;统计和动力降尺度方法模拟热带气旋频数和强度与观测检验证实,这些方法具有一定的模拟热带气旋的能力,但尚存比较大的不确定性;利用统计和动力降尺度模型及模式考虑21世纪人类排放增加全球变暖,较为一致地预估西北太平洋和北大西洋强台风(飓风)强度和频数都有可能增强。热带气旋和台风均属于给人类带来巨大灾难的极端气候事件,利用目前的统计和动力降尺度方法很难进行较为准确的未来年以上时间尺度的气候预测和预估,尚需对影响因子和预测与预估方法进行更加深入的研究,进一步减小预测和预估的不确定性。 相似文献
3.
本文利用美国国家环境预报中心1°×1°逐6h分析资料和半球观测系统研究与可预报性试验-亚太地区计划获得的云图资料,从背景条件、环流演变和背景场纬向风等方面入手,对西北太平洋地区的超强台风Sinlaku(2008)的生成过程进行了详细分析,探讨了近年来人们提出的热带气旋形成的新机制——波动临界层理论在这次台风生成过程中的... 相似文献
4.
根据美国联合台风预警中心热带气旋的数据(1979—2010年)以及NCEP/NCAR再分析风场和高度场的资料,从气候学角度分析了近32年夏季西北太平洋3类路径台风的大气准双周振荡的特征,并合成分析了6~10月3类路径台风生成时刻的原始环流、低频环流以及QBWO周期内低频环流的演变过程,结果表明:对流层低层至中层的大气存在明显的10~20 d准双周振荡特征,这对西北太平洋台风路径的预报有很好的指示作用;低频环流的演变特征表明,在西北太平洋地区,QBWO是通过低频气旋和低频反气旋来影响南海的季风槽以及副热带高压的强度和位置,进而对台风的生成位置和移动路径产生影响;菲律宾以东低纬度地区生成的低频气旋易于台风的生成,低频气旋的正涡度带走向和移动趋势预示着台风未来的移动方向;另外,在副热带地区同样存在着一支自西向东传播的大气准双周振荡波列,热带与副热带大气准双周振荡的相互作用对台风的路径产生了重要影响,这对台风路径的预报有较好的参考意义. 相似文献
5.
6.
台风对大跨度钢桁拱桥抗风性能的影响 总被引:2,自引:0,他引:2
采用Monte-Carlo台风随机模拟算法的结果和风荷载规范良态气象风环境参数建议取值,在大气边界层风洞中利用被动紊流发生装置再现了良态和台风2类气象条件下的风环境特征.以地处珠江流域台风多发区的广州新光大桥为例,采用全桥气弹模型风洞试验和基于主梁及肋拱测力试验的3维静风稳定性数值计算等手段,详细分析了中承式大跨度连续刚桁拱桥在2类风环境中平均风位移、风致抖振响应和3维稳定性的差异,分析过程比较了2类气象条件下重现期设计风速、平均风和紊流度剖面等因素对于拱桥抗风性能的影响. 相似文献
7.
8.
台风变性再度发展的动能收支分析 总被引:6,自引:0,他引:6
对1997年的台风Winnie登陆后的变性并再度发展过程进行了分析。发现低层的散度风制造是气旋强度变化的主要原因。在变性阶段,由于冷空气的侵入使低层的动能制造增加,对台风的维持起了主要的作用;在重新加强阶段,高空急流的影响使低层散度风的动能制造明显增加,使气旋斜压不稳定发展。讨论了台风登陆后再度发展的演变模型,可以认为是一种A类和B类温带气旋发展的混合类型,是一个低层变性气旋和高空低槽相互作用和相互发展的过程。 相似文献
9.
为什么要给热带气旋命名因为一个热带气旋常持续一周以上,在大洋上同时可能出现几个热带气旋,有了名字,就不易混淆。据说,首次给台风命名的是20世纪早期的一个澳大利亚预报员,把热带气旋取名为他不喜欢的政治人物,借此,气象员就可以公开戏称他。在西北太平洋,正式以人名为热带气旋命名始于1945年,开始也只用女人名,以后据说因受到女权主义者的反对,从1979年开始,用一个男人名和一个女人名交替使用。2000年1月1日起,西北太平洋地区启用了一套完全不同于以往的新命名表,它们均采用由WMO所属的台风委员会成员的14个国家和地区所提供的亚洲名… 相似文献
10.
热带气旋“浣熊”引发广东南部沿岸大暴雨分析 总被引:1,自引:1,他引:0
应用NCEP 1白1?的再分析资料、常规观测资料及地面加密观测资料分析2008年4月热带气旋“浣熊”引发的广东南部沿海地区大暴雨过程成因,结果表明:此次大暴雨过程是在南亚高压加强并向西北方向移动控制华南沿岸及南海北部,同时“副高”减弱东退的大尺度形势背景下发生的;南亚高压和“副高”之间存在“反向”而行的短期互动,而这种互动对大暴雨过程有重要影响;热带气旋向偏北方向移动过程中与高原东侧东移南下的槽在广东南部沿岸合并是引发大暴雨的重要天气系统;暴雨区上空存在对流不稳定,大陆冷高压东移出海过程大气边界层内回流弱冷空气是大暴雨过程不稳定能量释放的促发机制;大暴雨过程水汽源地是西太平洋和南海,来自西太平洋和南海的水汽在暴雨区上空辐合为大暴雨过程提供了充足水汽;大暴雨降落在热带气旋路径的右侧而不是热带气旋中心的四周,其原因是水汽和风场的辐合均发生在热带气旋路径的右侧,这是由热带气旋自身环流和大尺度环境气流共同决定的。 相似文献
11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness. 相似文献
12.
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly. 相似文献
13.
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well. 相似文献
14.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation. 相似文献
15.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。 相似文献
16.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death. 相似文献
17.
Miao Maosheng 《华南师范大学学报(自然科学版)》2014,(6)
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula- 相似文献
18.
Yang Weitao 《华南师范大学学报(自然科学版)》2014,46(6):137-138
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re- 相似文献
19.
Bernard Kirtman 《华南师范大学学报(自然科学版)》2014,(6)
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that 相似文献
20.
《上海师范大学学报(自然科学版)》2014,(5):550
<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with 相似文献