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141.
文中总结单舰航线水文气象保障业务的特点、难点,并结合航线水文气象保障的现状提出一些个人的建设性建议。  相似文献   
142.
Precipitation is a major component of the hydrologic cycle in arid desert areas. To date, however, few studies have been conducted on investigating the isotope characteristics and moisture sources of precipitation in arid desert environments. The Alxa Desert Plateau is a critical arid desert area in North China. This study is the first to analyse the stable isotopic composition of precipitation to identify the sources of atmospheric moisture over this plateau. Our results show that the δD and δ18O values of precipitation across the plateau change greatly at both daily and monthly timescales, and exhibit seasonal variations. Among the main meteorological parameters, atmospheric temperature is the most predominant factor controlling the isotopic composition and the δD–δ18O relationship of local precipitation. Analyses of the precipitation isotopes with the Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model reveal that (a) the westerly and polar moisture sources are the dominant controls on summer and winter precipitation and (b) the evaporation of local lake water significantly affects winter precipitation even though it only represents a small amount. Based on the isotope data of 2013–2016 precipitation, a local meteoric water line (LMWL) is derived: δD = (8.20 ± 0.22)·δ18O + (8.15 ± 2.16)‰ for the study site. Compared to the global meteoric water line, the LMWL has a greater slope and lower d‐excess. This can be explained by admixing of atmospheric moisture resulting from the evaporation of local lake water. Based on this LMWL, we are able to trace that groundwater of the Badain Jaran Desert originates from the surrounding mountains with altitudes of <4,000 m. The newly derived LMWL shows that the recharge altitudes of desert groundwater are overestimated on the basis of the previous LMWLs. This study not only provides insights into the hydrological cycle but also offers guidance for water resource management in arid desert areas of China. Additionally, this study provides techniques that can be applied to the analyses of precipitation isotopes in similar arid regions of the world.  相似文献   
143.
介绍了一个用汉字FOXBASE+语开发的动力气象试题库微机管理系统,着重阐述了动力气象试题库微机管理系统的设计思想及实施方案;系统的结构和功能;系统的数据库设计;实现该系统所实施的技术及编程中的有关特点以及系统的使用。  相似文献   
144.
BOOK REVIEWS     
Books Reviewed in this article: Lob Trees in the Wilderness . Clifford and Isabel Ahlgren . Satellite Microwave Remote Sensing . T. D. Allan , ed. Sunbelt Cities: Politics and Growth Since World War II . Richard M. Bernard and Bradley R. Rice , eds. Legacy of Minneapolis: Preservation Amid Change . John R. Borchert , David Gebhard , David Lanegran , and Judith A. Martin . Bloomington, MN: Preparing a Historic Preservation Ordinance. Richard J. Roddewig . The Mountains of Northeastern Tasmania, A Study of Alpine Geomorphology . Nel Caine . Introductory Cartography . John Campbell . Englewood Cliffs, NJ: Changing Climate . Manual of Remote Sensing, Second Edition . 2 Vols. Robert N. Colwell , ed.-in-chief; David S. Simonett and John E. Estes , vol. eds. Remote Sensing in Meteorology, Oceanography and Hydrology . A. P. Cracknell , ed. Multidimensional Scaling . Mark L. Davison . Environmental Karst . Percy H. Dougherty , ed. The Urban Environment . Ian Douglas . Geomorphology of Europe . Clifford Embleton , ed. An Introduction to South Asia . B. H. Farmer . Great Geological Controversies . A. Hallam . Hazardous Waste Management: In Whose Backyard? Michalann Harthill , ed. Energy for Subsistence . Margaret Haswell . Perspective on Ratzel's Political Geography . James M. Hunter . Economic Deposits and their Tectonic Setting . Charles S. Hutchison . Energy Risk Assessment . Herbert Inhaber . Discovering the Vernacular Landscape . John Brinckerhoff Jackson . Climate and Energy Systems: A Review of Their Interactions . Jill Jäger . Dilemmas in Regional Policy . Antoni Kuklinski and J. G. Lambooy , eds. California Farmland: A History of Large Agricultural Landholdings . Ellen Liebman . The Spatial Organization of New Land Settlement in Latin America . Jacob O. Maos . Dark Continent: Africa as Seen by Americans . Michael McCarthy . Westport, CT: Climatology: An Introduction . John E. Oliver and John J. Hidore . Columbus, OH: The Geography of Warfare . Patrick O'Sullivan and Jesse W. Miller . The Expanding City. Essays in Honour of Professor Jean Gottmann . John Patten , ed. Scotland's Environment During the Last 30,000 Years . Robert J. Price . Integrated Urban Models . S. H. Putman . Development and the Environmental Crisis: Red or Green Alternatives? Michael Redclift .  相似文献   
145.
本文用两种不同日夜分界限统计了成都、重庆的P-T大气稳定度频率。结果表明,两种分界统计大气稳定度频率,不稳定类完全相同;以h=0分界比以h=k_1分界中性频率增加,稳定频率减少,两者频率差值大小与地理位置、气候和天气特征有关;这与理论分析完全符合。通过对比指出,h=0分界的应用有局限性。同时,通过计算表明,实际工作中,太阳赤纬σ每十日取一概略值已足够精确了。  相似文献   
146.
文章按照标准化、集约化、智能化的理念,基于云端部署技术,提出了宁夏智能化综合气象业务服务共享管理平台的设计思路和总体架构,建设了宁夏气象基础数据库、业务产品库、服务产品库,构建了业务产品自动化生成系统、服务产品智能化制作系统、服务信息智慧型发布系统和信息共享与管理系统。通过数据存储、数据服务接口、数据资源管理、数据加工流程的标准化,设计了以标准化体系为基础的集约化数据环境。通过数据环境集约和业务系统集约,设计了以数据驱动为特征的集约化产品加工系统,形成统一的数据加工流水线。突出智能化要求,设计了以智能化为目标的数据分析算法和智能化系统运行控制,并在业务产品自动化生成、服务产品智能化制作、服务信息智慧型发布方面进行了探索。平台设计理念先进,技术前沿,流程简洁,功能完备,运行高效,充分体现了数据资源标准化、业务系统集约化和计算运行智能化的要求,平台的开发建设将极大地推进宁夏气象现代化进程,对于发展智慧气象具有重要的参考价值。  相似文献   
147.
通过NCEP再分析资料和Micaps实况资料对"尤特"发生发展以及登陆过程的水汽条件、螺旋度变化进行分析,发现:"尤特"在发生发展前期,西南急流和副高南侧偏东气流对"尤特"水汽输送作用相当,中后期"尤特"则主要以西南急流形成的南支水汽通道输送为主,水汽的源地主要来自南海.对于广西强降雨区,在"尤特"进入广西前,该区为一个水汽源,南边界水汽输出显著,而到了15~19日主要降雨发生时段,受南支水汽输送带的影响,广西强降雨区转为水汽汇,水汽输入以南边界为主.环境场水汽通量和水汽通量散度的变化对"尤特"强度的变化和移向有一定的指示作用,"尤特"在加强或减弱前,其中心水汽通量往往先加强或减弱,且在台风维持一定的强度时,"尤特"有趋向周边水汽大值中心移动的趋势."尤特"水汽辐合主要位于低层,其强降雨区与850~950h Pa水汽通量散度场、850h Pa螺旋度相对大值区内有一定的对应关系,未来6h强降雨区多出现在低层强度强、垂直伸展高度高的水汽辐合区和螺旋度相对大值区内.  相似文献   
148.
149.
This paper provides an overview of the impacts of the original works of Professor Duzheng YE on a selected set of observational and model studies with which the present author has been associated over the past several decades. The main themes of these works include atmospheric energy dispersion, air–land interactions over the Tibetan Plateau, and El Ni n?orelated air–sea coupling over East Asia.The dispersive behavior of observed atmospheric fluctuations accompanying cold surge events in East Asia is demonstrated. Cold air outbreaks over Korea and southern China are coincident with the successive downstream development of troughs and ridges, with the group velocity of such wave packets being notably faster than the phase propagation speed of individual troughs and ridges. In a more general context, dispersive features are also discernible from lagged teleconnection charts and cross-spectra of observed and model-simulated geopotential height variations on 10–30-day time scales.Using the output from a high-resolution general circulation model, the relative contributions of condensational, sensible, and radiative heating to the atmospheric energy budget over the Tibetan Plateau are documented. The rapid changes of the upper tropospheric Tibetan anticyclone and East Asian mei-yu("plum rain") precipitation band associated with the development of the Asian monsoon system are described.The principal anomalies in sea level pressure, surface wind, precipitation and sea surface temperature over southeastern China and the Philippine Sea region during El Nio events are presented. The contributions of remote El Nio-related forcing and local air–sea interaction to the occurrence of these anomalies are assessed.  相似文献   
150.
针对水汽含量在短时间内变化快、影响因素多,目前精确测定其含量仍是一个难点的现状,该文采用GAMIT软件,利用两次暴雨发生过程中香港地区6个连续运行参考站系统参考站数据,计算天顶对流层总延迟(ZTD)和大气可降水量(PWV),并与实际降雨量进行对比。研究结果表明,暴雨发生前后的1~2h或者更长时间内,天顶对流层延迟、大气可降水量和实际降水量一直保持着较好的对应关系,天顶对流层延迟和大气可降水量会出现骤增和骤降现象,而且天顶对流层延迟和可降水量的变化速度越快,说明大气环境越不稳定,降水概率也就越高。  相似文献   
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