夏季风变异与我国持久性旱涝     

段月薇 《地理研究》1984,3(4):59-69

本文根据1978—1981年4年的流场,相当位温和湿度场资料讨论了夏季风年际变异与旱涝的关系,着重分析了1978—1980年3年南北半球低纬度700毫巴等压面流场来了解夏季风几支气流与旱涝的关系。  相似文献   

关于积云增雨和实施方案的探讨   总被引：2，自引：1，他引：1  

许焕斌  田利庆  段英 《气象科技》2005,(Z1)

在综合雷雨云式的积云降水特点和归纳观测及理论结果的基础上,用数值模拟研究了阵雨形成机制,发现雷雨云式的积云结构类似于雹云,也存在着水平风“零域”和成雨“穴道”,大粒子群向这里集中并累积,然后再下泻成阵雨。据此提出了积云人工增雨的动力学根据和设计实施方案的要领,并给出了积云人工增雨作业部位、时机的概念模型。  相似文献   

Heating status of the Tibetan Plateau from April to June and rainfall and atmospheric circulation anomaly over East Asia in midsummer   总被引：20，自引：0，他引：20  

DUAN Anmin  LIU Yimin & WU Guoxiong State Key Laboratory of Numerical Modeling for Atmospheric Sciences  Geophysical Fluid Dynamics  Institute of Atmospheric Physics  Chinese Academy of Sciences  Beijing  China 《中国科学D辑(英文版)》2005,48(2):250-257

Based on the 1958-1999 monthly averaged reanalysis data of the National Center for Environmental Prediction (NCEP)/National Center for Atmospheric Research (NCAR) and the rainfall data of 160 Chinese surface stations, the relationship between rainfall and the atmospheric circulation anomaly over East Asia (EA) in July and the sensible heating (SH) over the Tibetan Plateau (TP) from April to June (AMJ) is investigated by using the rotational experimental orthogonal function (REOF) method. The results show that the TP is an isolated heating source in this period. The lagged correlation analysis between the first rotational principal component (RPC) of SH over the TP in May and rainfall of EA in July demonstrates that strong SH over the TP before July leads to a positive rainfall anomaly over the TP, the valley between the Yangtze River and Huaihe River, and the regions south and southeast of the TP, and the Sichuan Basin and Yunnan-Guizhou Plateau, but less rainfall anomaly over the regions north, northeas  相似文献   

中国中、东部典型样区不同发展水平下土壤与土地利用多样性的对比分析(英文)   总被引：1，自引：0，他引：1  

段金龙  张学雷 《地理学报(英文版)》2012,22(6):1101-1116

Two typical provincial capitals (Nanjing and Zhengzhou) and two counties (Rugao and Yuanyang) in east (Jiangsu Province) and central (Henan Province) China were chosen respectively as the developed and less developed comparative cases for pedodiversity and land use diversity correlative analysis by borrowing the recently better developed pedodiversity methodology. Land use classification was worked out using remote sensing images in three different periods (1986-1988, 2000-2001 and 2004-2006) for these studied case areas before the calculation of the constituent diversity index and spatial distribution diversity index modified after Shannon entropy in 2 km×2 km grid scale of the soil and land use pattern were conducted and then a connection index was proposed to evaluate the relationship between soil and land use diversity. Results show that during the years from 1986 to 2006, the composition and spatial distribution of regional land use pattern had changed greatly. The agricultural land area of all the studied case areas decreased obviously in which Nanjing has the highest decrement of 895.98 km 2 mainly into urban use while the other land use type area changes show the same trend. The connection index of four typical soil family types and typical urban land use types, i.e., urban construction land, transportation land and industrial and mining area all increased in this period. In the studied case areas, there is the highest soil constituent diversity in Zhengzhou at 0.779 while the simplest soil constituent diversity in Rugao at 0.582. Meanwhile we have higher land use diversity in the more urbanized Jiangsu Province than Henan Province, Nanjing is ranking the first that has been getting higher and higher in the three periods at 0.366 in 1986-1988, 0.483 in 2000-2001 and 0.545 in 2004-2006. Finally, the connection index figures to evaluate the relationship between soil and land use diversity of the studied areas were compared to show the similar phenomenon that this figure grows fastest in Nanjing followed by Zhengzhou and other places.  相似文献   

Genetic diversity of wild barley (Hordeum vulgare ssp. spontaneum) and its utilization for barley improvement     

XiaoYing M  Chao Li  AiDong Wang  RuiJun Duan  GenLin Jiao  Eviatar Nevo  GuoXiong Chen 《寒旱区科学》2012,4(6):0453-0461

Wild barley (Hordeum vulgare spp. spontaneum) is the undisputed progenitor of cultivated barley and offers considerable potential as a genetic resource for barley improvement. Naturally occurring populations are distributed primarily across the Fertile Crescent, but secondary areas of diversity are also found in central Asia and Tibet. The pattern of its genetic diversity is non-random, and is structured on a global, regional and local scale. On a global scale, diversity follows ecogeography, while on a regional and local scale, it is more strongly determined by ecology. Populations growing in areas where the climate is unreliable and/or the soil is heterogeneous tend to retain the most diversity. A large number of accessions are currently conserved ex situ, but a high proportion of these have originated from the Fertile Crescent. Given the likelihood of future climate change, conserving germplasm both in situ and ex situ in the various regions where the species’ currently existing is a research priority. The value of H. vulgare spp. spontaneum for the improvement of cultivated barley lies largely in its potential contribution to the levels of attainable pathogen resistance and abiotic stress tolerance.  相似文献   

月动力延伸预报产品在新疆月尺度降水预测中的应用检验     

段均泽 《沙漠与绿洲气象(新疆气象)》2012,6(6):61-64

利用新疆101个气象观测站点逐月降水实况资料和2001~2010年国家动力气候模式产品,进行月动力延伸预报产品的应用预测检验。采用PS评分和同号率对内插预测结果进行效果评估,并与业务评分进行对比。结果表明：月动力延伸预报产品对新疆地区月降水趋势预测Ps评分高于业务评分,而对各月降水距平百分率的同号率差异较大。夏、秋季Ps评分较高,冬、春季PS评分较低,季节转换时预测Ps评分变率较大。  相似文献   

基于Web Service的气象预警短信发布系统设计与实现     

王赟  段燕楠  姚愚  李晓鹏 《气象科技》2012,40(3):384-387

昆明市气象预警信息发布系统是以提高预警信息及时性和发布效率为出发点,整合了不同种类自动气象站的数据资源,与气象业务平台无缝集成,实时监控数据并生成满足需求的气象预警短信,通过预警号码管理数据库,确定预警信息受众范围,实现了预警短信服务的自动化、标准化、规范化。信息编辑不再需要人工干预,信息发布摒弃了原有的GPRS通信、GSMModem通信、运营商提供短信发布平台等方式,基于Web Service技术直接接入电信短信网关,实现了气象预警信息的高效发布,提高了气象服务的整体质量和效率。  相似文献   

基于位置误差的分布制作热带气旋路径袭击概率预报   总被引：3，自引：1，他引：2  

高拴柱  张守峰  钱传海  端义宏  王海平 《气象》2009,35(9):38-43

为了探讨热带气旋路径预报的不确定性,利用2004-2007年4年中央气象台综合预报的误差分布状况,建立热带气旋路径综合预报的统计集合模型,制作热带气旋路径的袭击概率预报及产品,并为警报发布工作中有关登陆地段的预报提供有意义的参考.  相似文献   

登陆孟加拉湾风暴结构个例分析与数值模拟   总被引：1，自引：0，他引：1  

王曼  李华宏  段旭  刘建宇 《气象科技》2009,37(1):12-18

采用NCEP-NCAR再分析资料,分析了2006年4月29日登陆缅甸并造成云南省强降水过程的孟加拉湾风暴结构。并且利用美周新一代中尺度WRF（weather Researchand Forecast）模式对2006年4月28～30日云南强降水过程进行了数值模拟研究。结果表明：孟加拉湾风暴登陆前后结构具有明显变化,从基本对称结构演变为非对称结构,WRF模式较好地模拟出盂加拉湾风暴登陆前后环流场特征和风暴移动路径以及造成云南强降水雨带的分布特征。  相似文献   

鹤壁市夏季一次雹暴过程的成因分析   总被引：1，自引：0，他引：1  

邢用书  孙日丁  段秀英  李忠亮  徐朝晖  陈静 《气象与环境科学》2009,32(Z1)

运用天气图、物理量场、卫星云图、雷达回波及相关气象资料,分析了2005年6月19日发生在鹤壁的雷雨大风、并伴有局地冰雹的强对流天气过程.结果表明:在低层θse高能舌区内,地面冷锋移到 500 hPa高空急流出口区下方左侧时,高低空次级环流耦合,触发不稳定能量释放、产生强烈的上升运动,是这次强对流天气产生的直接原因.  相似文献