台风暴雨大气熵变场的诊断和对比分析

本文借助于熵平衡方程，对两个深入内陆的台风暴雨过程在负熵流作用下的减熵运动进行了诊断和对比分析，得到了以下结果:（1）台风大范围暴雨和强的负熵变相对应，因此可比常规方法较好地分辨出暴雨落区；（2）负熵变的汇合能够清楚地反映出中、低纬度天气系统的相互作用，为特大暴雨和台风远距离影响的特大暴雨的出现提供先兆；（3）本文导出的熵密度变化方程可以阐明，雨区内系统的发生、发展是和降水导致熵减小的物理过程相联系的；（4）大气熵辐散，特别是中、高层的熵辐散，对暴雨发生和持续的作用，不仅和潜热加热同样重要，甚至更有决定性意义。     

1994年江淮地区首次区域性春季暴雨诊断分析

分析了１９９４年４月１９－２０日春季暴雨主枚是由对流层中低层涡和地面静止锋共同作用的结果，侧重于对低空急流的形成与变动和熵平衡方程的诊断分析，能量场与该次暴雨有很好的相关性。     

1996年6月25日苏州暴雨与熵的变化

根据耗散结构理论,用局域的熵密度平衡方程,在有限区域内计算了1996年6月25日苏州非对流性暴雨的变熵值和有关物理量,初步分析了这次暴雨过程的一些特征。     

一次淮北连续暴雨的熵分析

本文分析了完全的熵平衡方程中各项对暴雨的作用,作者认为先有外界能流和质流对系统的贡献,导致熵不平衡,与此同时系统内部自行调整使熵趋于平衡,从而产生气流的上升运动。因此,外界供给的能流和质流越大,系统偏离平衡态越远,造成的降水也越大。本文通过一次淮北连续暴雨过程的实例,证明了以上结论。     

一次特大暴雨过程的熵诊断分析

前言近年来，用熵平衡方程判断大气中对流和降水的发生，从理论上已进行了论证。但是在实际工作中应用还不多见。本文将此方程用于暴雨天气过程作诊断分析。1天气概况1995年6月4～8日，粤西地区普降暴雨到大暴雨。其中6～7日，阳江、阳西、电白、吴川站降了特大暴雨，6日14时一7日14时阳江市区降雨量达615mm。6－8田阳西县溪头镇降雨量达ilO4mm。5－7日电白县沿海11个镇普降大暴雨。据报导，麻岗镇降雨量超过70Omm。7日早晨吴）11降特大暴雨。因这次过程雨强大，降水时间长，使粤西部分地区出现了严重的洪涝灾害。2天气形势及影gN系统6月4…     

国家气象中心降水数值预报信息效益评估

以列联表形式计算熵函数，由熵函数值对国家气象中心发布的１９９６年汛期６月２２日－８月７日５次暴雨过程降水数值预报进行评估，得到５种数值预报产品给江苏省各区域的雨量预报提供了０．１８２４ｂｉｔ－０．２９１４ｂｉｔ信息等结论。     

甘肃省河东一次暴雨过程的熵诊断分析

1990年8月11—13日甘肃省黄河干流以东(简称河东)地区出现了暴雨天气过程。天气形势分析发现:暴雨出现在500hPa 最大西南风轴线右侧和700hPa 兰州低涡的强辐合区内。这是一次大环流调整后的西太平洋副热带高压西伸北抬以及冷暖空气在其边缘交馁的结果。应用熵平衡方程,并配合水汽通量散度、涡度的计算发现,暴雨区位于熵的负值中心和水汽汇的叠置区域中,且暴雨区的移向与熵的负值中心一致。     

“89．7．9”川东北持续性特大暴雨的中尺度分析

通过对常规资料作计算分析，并结合时间间隔比较密结的卫星云图资料，对１９８９年７月９－１０日发生于四川盆地东北部的暴雨天气过程，中尺度特征进行了详细分析，揭示了与暴雨天气相联系的中尺度涡旋的活动特征以及大气内部非平衡强迫在暴雨发生、发展过程中的作用。提供一些对暴雨分析预报有价值的线索。     

熵的演化与暴雨形成和落区的探讨

应用耗散结构理论，提出了大气中“湿滴”的具体计算公式和“相对湿滴”的概念，推导了便于在大气中实际应用的总熵流表达式。结合湖北省两次暴雨及特大暴雨天气过程，初步分析归纳了熵的演化与强对流暴雨和落区的关系；熵的演化与台风低压引发的暴雨和落区的关系，指出了两种暴雨过程的共同点和不同点；对台风低压的移动规律得到了某些有益的认识。     

开放多相系熵密度平衡方程在暴雨预报中的应用

利用耗散结构理论的相关知识,从非平衡态理论的熵密度平衡方程出发,计算了2004年6月23日发生在湖南西部和北部地区暴雨发生前24h至暴雨结束前12h每隔6h对流层中低层的熵变场。通过对各个不同时刻的熵变场的分析与比较,讨论了熵场变化与暴雨区域、强度及其演变之间的关系,为暴雨强度和落区预报提供了参考指标。     

Some features of sea ice formation in Antarctic coastal waters

Considered are the peculiarities of fast ice formation in the Antarctic coastal waters. It is noted that the fine-crystalline ice with the chaotic orientation of crystals is mainly developed in the surface layers of the ice cover as well as the ice formed due to the infiltration of the sea water and its subsequent freezing in the lower layers of the snow cover. It is demonstrated that under the conditions of coastal Antarctic, the lamination of the structure during the period of ice cover formation and its subsequent development is the result of heavy precipitation in the form of snow and the formation of the large amount of snow sludge and crystals of intrawater ice (frazil ice) on the open water. The main distinctive feature of the Antarctic sea ice is its seasonal stratification with the formation of the surface layer of recrystallized ice and underlying destructive layers including the water interlayer in the ice column. The provision of the safety of overice movement of machinery requires the development of methods of continuous remote control of the snow-ice stratum of the fast ice.     

Variability and conjugacy of ice conditions in the system of east arctic seas (the Laptev, East Siberian, and Chukchi Seas)

The analysis of the long-term variability and spatiotemporal conjugacy of formation processes of ice conditions in the water areas of the Laptev, East Siberian, and Chukchi seas is carried out on the basis of the available data on the ice cover conditions in the above seas. On the whole, the type of relationships between the ice processes in the system of East Arctic seas indicates the existence of certain mechanisms generating the wave processes in the climatic system of the Arctic Basin manifested in the phase opposition in the development of ice conditions on the western and eastern peripheries of the basin under consideration. The statistical analysis of series of the ice coverage of water areas under consideration demonstrated that the existence of the long-term trend of this characteristic in some seas has its spatiotemporal features: the probability of the trend existence increases from west to east (from the Laptev Sea to the Chukchi Sea) and the trends are of opposite signs.     

A correspondence between the model ensemble simulations and observations of temperature changes on the territory of Russia

The results are presented of the statistical analysis of correspondence between the model simulations and observations of temperature changes on the territory of Russia. Three model ensembles are considered, differing in the level of taking account of the impact of external forcings on the climate system of the Earth. For each of them, the statistical correspondence is estimated between the observed surface air temperature variations in the second half of the 20th century and at the beginning of the 21st century and model simulations taking account of the natural variability typical of the climate system. The analysis demonstrated that, in spite of the uncertainties associated with the differences in the representation of anthropogenic and natural external forcings on the climate in model simulations as well as with the imperfection of climate models and with internal variability of the climate system, the model experiments enable to obtain the relevant information both on the temporal evolution of temperature changes on the territory of Russia and on their spatial peculiarities.     

热带气旋强度变化研究进展

自20世纪90年代后期以来,热带气旋强度变化研究越来越受到人们的重视,随着研究的不断深入,热带气旋强度变化研究取得了可喜的进展,文中总结近年来热带气旋强度变化的主要研究成果,主要包括(1)热带气旋的发生、发展和最大可能强度的研究;(2)行星涡度梯度、环境均匀流、环境流场垂直切变以及热带气旋外流与环境流的相互作用对热带气旋强度的影响及物理机制;(3)热带气旋结构与强度的变化关系,着重总结环境流场导致的非对称结构变化而引起的热带气旋强度变化以及对涡旋倾斜发展理论验证,分析了涡旋Rossby波的最新研究;(4)海洋热状况变化以及海洋飞沫对热带气旋强度的影响研究成果。分析指出,今后进一步开展用现代化卫星探测资料研究热带气旋强度变化外,还应加强热带气旋外流与环境流场的相互作用,海-气交界面的参数化问题,热带气旋结构变化与TC强度变化关系以及这种关系的物理本质的研究,通过深入研究,认识热带气旋强度变化的物理机制,提高热带气旋强度变化的预报能力。     

两个中尺度对流系统的降水结构和闪电特征

对两个处于不同发展阶段的中尺度对流系统(MCS)降水结构的分析结果表明,处于初生至发展阶段的MCS,对流降水和层云降水的面积比相对较大,处于成熟至消亡阶段的MCS的相对较小。本文进一步分析了这两个MCS个例在6km高度处的雷达回波特征及其和闪电的关系,结果表明处于初生至发展阶段的MCS的绝大部分事件(闪电资料的一种)集中发生在MCS中的强对流单体回波区,而对处于成熟至消亡阶段的MCS,事件集中发生在对流区和对流云向层云转化的回波区。     

STUDY ON SENSITIVITY OF WIND FIELD VARIATION TO STRUCTURE AND DEVELOPMENT OF CONVECTIVE STORMS

A numerical experiment was carried out on individual cases of severe convections in the Jianghuai area under cold vortex on April 28, 2015 in order to study the impact of wind field variations at the middle and low troposphere on the development and structure of storms. The results show that the structure and development of convective storm is highly sensitive to the changes of wind fields, and the adjustment of wind field at the middle or low troposphere will lead to significant changes in the development and intensity of storms. When the wind field at the middle or low troposphere is weakened, the convective development suffers different degrees of attenuation compared with the control experiment, and the ways of attenuation of the two levels are different. In the attenuation test of wind field at the middle level, convection is obviously weak at all stages of its development, while for the wind field at the low level, the convective development is weak only in the initial development stage of storm. On the contrary, the enhancement of the wind field at the middle or low troposphere is conducive to the development of convection, especially the enhancement of the wind field at the middle troposphere. In comparison, the convection develops rapidly in this test, as the most intensive one. The wind field variations have a significant impact on the structure and organization of the storm. The enhancement of the wind field at the middle troposphere makes for the intension of the middle-level swirl of convective storm, the reduction of the storm scale, and the organized evolution of convection. The development of the wind field at the low level troposphere is conducive to the development of the low-level secondary circulation of the storm and the cyclonic vorticity at the middle and low levels at the inflowing side.     

Atmospheric dynamics in the center of the European part of Russia during intensive snowfall in April 2012

The dynamics of atmospheric characteristics in the zone of the cyclone which provoked the dangerous atmospheric phenomenon, the heavy snowfall over the center of the European part of Russia in April 2012, is studied using the data of surface and satellite measurements. Besides the observational data from the meteorological stations, the results are used of the measurement of meteorological variables at the high-altitude meteorological mast in Obninsk and of surface concentration of minor gas components. Revealed is a number of interesting features associated with the passage of the cyclone cloud system over the observational point: the dramatic air temperature drop throughout the 300-m layer of the atmosphere, the formation of intensive vertical motions, and the significant temporal variability of O₃ and NO₂ concentration. The intensity and the total amount of precipitation falling during the cyclone passage are determined using the data of optical measurements of SEVIRI, AVHRR, and MODIS instruments of geostationary and polar orbiting satellites. Demonstrated is the satisfactory agreement of the computed precipitation characteristics with the results of observations at the network of meteorological stations.     

Hydrodynamic processes on the Sakhalin shelf in the coastal Piltun area of the grey whale feeding and their correlation with atmospheric circulation

Discussed are the results of long-term hydrophysical studies carried out on the northeastern shelf of Sakhalin Island in the area of summer-autumn fattening of the Okhotsk-Korea population of grey whales. It is demonstrated that the inflow of water desalinated by the Amur River runoff and the coastal upwelling caused by the summer monsoon are of great importance for the hydrological regime in the given area. These phenomena are interrelated and depend on interannual variations of atmoispheric circulation. Presented are the results of studying the parameters of internal waves obtained using the anchored autonomous vertical system of measurement. Measured are the velocities of the orbital movement of water particles in the propagating nonlinear internal waves and the respective vertical displacements of water layers. Demonstrated are the peculiarities of the thermohaline structure of water under the slick formed on the sea surface by the internal wave.     

建筑物上侧击雷电的三维数值模拟

基于三维近地面闪电先导发展随机模式,通过改变先导初始电位和建筑物几何特性,分析各种情况下的侧击雷电发生概率,探讨侧击雷电产生原因及影响因素。结果发现:建筑物尖端电场畸变值是影响侧击雷电产生的重要参量,当下行先导靠近建筑物且传播位置低于建筑物的高度时,建筑侧面电场畸变值达到触发阈值,侧击雷电易产生;下行先导的初始电位以及建筑物几何特性（高度和宽度）是影响侧击雷电发生概率的重要因素,当下行先导初始电位在-9~-3 MV范围内,侧击雷电发生概率呈先增加后降低的趋势,当初始电位为-4.5 MV时,侧击雷电的发生概率达到峰值;当建筑物高度在50~150 m范围内,侧击雷电发生概率随着高度增加呈先增加后减少的趋势;当建筑物高度为100 m时,侧击雷电发生概率达到峰值;当建筑物宽度在30~70 m范围内,侧击雷电发生概率随建筑物宽度呈递减趋势;当建筑物宽度为30 m时,侧击雷电的发生概率达到峰值。