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针对2008年6月29日下午到夜间,发生在山西省忻州市神池、五寨、原平等县(市)一带的严重局部冰雹天气过程,利用天气环流形势,各种物理量特征,分析其成因。指出:a)500hPa蒙古东部的冷涡东移,冷空气叠加在850hPa暖脊上,产生上冷下暖的位势不稳定能量。b)前期先导槽的滑过,使低层增湿,潜在不稳定度增大。c)降雹区域沙氏指数、K指数等都符合山西降雹标准。d)850hPa-500hPa有较强垂直风切变,使动力不稳定能量加强,为冰雹天气发生发展提供了必要条件。e)特别是山区由于海拔高,山脉阻挡,气流辐合上升,容易产生局地强对流,诱发雹云生成,出现冰雹天气。 相似文献
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吐鲁番一次典型翻山大风的动力机制分析 总被引:1,自引:0,他引:1
2004年6月2日吐鲁番盆地出现一场大风。大风引发严重火灾,烧毁民房数百间。这场大风属于典型的翻山大风,预报有一定难度。本文从天气学角度分析了形成这场大风的动力机制,为预报此类天气提供依据。另外,根据大风前期吐鲁番单站天文动力结构特征分析,也解释和印证了这场翻山大风的内在动力机制。 相似文献
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极涡研究进展 总被引:15,自引:1,他引:14
极涡是北极地区的一个深厚系统,它以极地为活动中心,最能体现高纬大气活动特征,属大气环流最主要的系统之一,通常与副热带高压、阻塞高压、季风等环流系统相互配合,在全球天气气候变化中起着至关重要的作用。本文就极涡的气候特征、对天气气候的影响、变化机理及数值模拟等几方面的研究进展进行综述。在行星波破碎、平流层爆发性增温、平流层对流层的动力耦合等过程中,极涡也扮演着重要角色;极涡对HNO3、臭氧等大气化学成分渗吸和输送过程的影响显著,而这些化学成分的再分布对极涡有较强的反馈作用;极涡还受到海温、冰雪、植被甚至太阳活动等的影响。前人已经关于极涡做了不少研究,但在气候动力学方面,还存在一些问题,有待进一步加强研究。 相似文献
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《Atmospheric Research》2009,91(2-4):338-355
This paper summarises the development and principal results of fifty years of research on aerosols in the marine atmosphere at Mace Head Atmospheric Research Station on the west coast of Ireland. It concentrates on the sources, physico-chemical properties, number and mass concentrations, size range, volatility and chemical composition of aerosols in different air masses. It also examines optical properties of the aerosols and their long-range transport. 相似文献
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从大气基本运动方程及大气总能量概念出发,提出将大气动力学与能量天气学相结合的物理量——干能量位涡与湿能量位涡,并确定其守恒性.通过分析发现,以静力温度表达的能量位涡数学计算更方便,物理意义更明确.以2007年湖北的一次典型雷雨大风天气为例,对雷雨大风天气用能量位涡进行诊断分析.结果表明:本文提出的干能量位涡与湿能量位涡可以较好地预示雷雨大风天气,高空干能量位涡的增强与向下发展使对流层中下层不稳定能量增大,有利于雷雨大风天气发生;低层湿能量位涡的不稳定能量高值区与斜压系统耦合时预示该区域将有雷雨大风发生. 相似文献
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This paper summarises the development and principal results of fifty years of research on aerosols in the marine atmosphere at Mace Head Atmospheric Research Station on the west coast of Ireland. It concentrates on the sources, physico-chemical properties, number and mass concentrations, size range, volatility and chemical composition of aerosols in different air masses. It also examines optical properties of the aerosols and their long-range transport. 相似文献
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N. I. Grigor’eva 《Russian Meteorology and Hydrology》2012,37(5):332-337
Presented are the data of observations carried out in the fall of 2000 in the Gavan?? Gaidamak Inlet (Vostok Bay, Peter the Great Bay, Sea of Japan). It is revealed that the main transport of water takes place in the surface horizons from 0 to 1?C2 m predominantly in the meridional direction (north-south). It is demonstrated that in spite of not being under wind influence, the inlet area has a high degree of water flow turbulization. It was also registered that the wind-induced phenomena promote the development of turbulent processes and serve as the main self-cleaning mechanism of the inlet. 相似文献
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回顾了中央气象台60年来,数值天气预报(NWP)业务系统的发展历程。指出NWP系统是一项气象工程系统建设,是多学科理论和技术相结合的结果。回顾了从目标方向、技术路线、工作方式、人才队伍培养以及土建设计等方面的科学决策和实践过程,阐述了科学决策是业务系统建设持续发展的根本保证。从建设事例中可以看到30年来NWP顺利发展的历史证明了科学发展观的正确性。 相似文献
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N. Ts. Gomboev 《Russian Meteorology and Hydrology》2007,32(12):750-753
It is shown that the influence of coherence of radiometeorological parameters on errors in their sample statistical characteristics must be taken into account. Formulas are proposed for estimating errors in calculating the mean and standard deviations of radiometeorological parameters with consideration of their coherence. It is shown that these errors under particular conditions may be 1.5 to 2 times as large as those calculated without taking into account their coherence. 相似文献
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本文将长治市划分为南、北、东三部分,并各选取一个代表站,作为研究对象,资料年代为1961年-2005年。将其45年来各气象要素的分析与全球、全国气候变化对比,得出以下变化事实:近40年长治年降水量呈明显下降趋势(-22.53mm/10a),秋季降水量呈下降趋势(-11.85mm,10a),冬季降水量呈略微上升趋势。年平均气温呈上升趋势(0.20℃/10a),特别是20世纪90年代增温显著,尤以冬季增温明显(0.525℃/10a),夏季气温有略微下降趋势。进入21世纪降水趋于增多,而气温仍趋于增高。统计气温资料表明,20世纪60年代为偏冷期,90年代是最暖的10年,而1998年和1999年是最暖的年份。 相似文献
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T. W. Krauss A. A. Sin’kevich N. E. Veremei Yu. A. Dovgalyuk V. S. Makitov V. D. Stepanenko 《Russian Meteorology and Hydrology》2011,36(3):167-174
Development of a long-living Cb cloud in the desert part of Saudi Arabia on April 10, 2008 is analyzed. Continuous satellite and radar observations of the cloud are carried out during five hours. Numerical modeling of the cloud is performed using a nonstationary 1.5-dimensional model. Data on the Cb cloud and its anvil development dynamics are obtained. It is shown that the anvil characteristics differ significantly in the zone of its formation directly over the cloud and when moving away from it. It is pointed out that the radar underestimates the anvil sizes. Estimation of precipitation rate from the cloud under study by means of satellite and radar measurements is compared against the results of numerical modeling. It is found that precipitation rate could reach 100 mm/h. The radar estimates of the precipitation rate are significantly overstated, which is, in this case, due to presence of large hail particles. 相似文献
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The Conservation of Helicity in Hurricane Andrew (1992) and the Formation of the Spiral Rainband 总被引:5,自引:0,他引:5
The characteristics of helicity in a hurricane are presented by calculating the MM5 model output in addition to theoretical analysis. It is found that helicity in a hurricane mainly depends on its horizontal component, whose magnitude is about 100 to 1000 times larger than its vertical component. It is also found that helicity is approximately conserved in the hurricane. Since the fluid has the intention to adjust the wind shear to satisfy the conservation of helicity, the horizontal vorticity is even larger than the vertical vorticity, and the three-dimensional vortices slant to the horizontal plane except in the inner eye. There are significant horizontal vortices and inhomogeneous helical flows in the hurricane. The formation of the spiral rainband is discussed by using the law of horizontal helical flows. It is closely related to the horizontal strong vortices and inhomogeneous helical flows. 相似文献
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赵志伟 《南京气象学院学报》2002,25(6):853-858
提出了一种具有零电流关断(ZCS)的反激式单级功率因数校正(PFC)变换器。这种变换器工作在完全能量转换方式(DCM)下,综合了电流谐振技术与PFC技术。分析了这种变换器的工作原理,并在输出30W条件下进行了实验验证。 相似文献
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文中介绍了机交互处理系统中用于客观分析和图形低处理矩形网格的设计与开发,实现了经纬度坐标向网格坐标和屏幕坐标的目标转换以及离散点资料向网格点的自动插值。计算机自动设计的网格,其范围和格距的大小具有可变性,为资料的经处理、天气图的填绘1、图形图象的缩放与漫游等提供了便利。 相似文献
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DECIDE2是一种高效的应用软件,它能在大量的样本中挑选出最佳因子,能从历史数据资料中总结出预报经验及进行某些应用气候的分析等。该软件由C语言写成,用户界面良好,操作十分简单。 相似文献