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1.
本文介绍在IBM-PC微机(或兼容机)上利用DBASEⅡ、BASIC和FOR-TRAN语言设计和研制的一套大气边界层气象资料数据库软件系统,给出它的主要结构和功能。该系统实现了大气边界层气象资料共享和信息化处理,不但操作简便、快速、准确、稳定性好,而且具有较强的通用性和较大的实用价值。  相似文献   

2.
为了求解对流边界层理论中一个非自治微分方程系统,作者采用伽略金有限元方法,此方法是通过将无限区间上的三阶非线性微分方程转化成有限区间上的二阶微分形式,并构造出相应的伽略金有限元方程来求得数值解,该数值解与先前一些作者的结果一致,并且计算效率显高于其它数值方法.  相似文献   

3.
利用NCEP再分析资料为背景场及常规的探空资料和地面资料,以2005年6月2日出现在黄海海域的大气波导为例,运用中尺度数值模式MM5,设计了2种初始场不同的数值模拟试验:1)NCEP资料;2)NCEP资料和常规探空资料。研究结果表明:格点同化能够改善大气波导的MM5数值模拟结果,提高MM5的大气波导参数模拟精度;在大气波导分布上,格点同化对陆地大气波导影响较大,对于海上的模拟区域分布几乎没有影响。  相似文献   

4.
结合气象观测和大气边界层探测资料,分析了1990年1月2日重庆雾的声雷达回波特征,并与1989年12月30日雾的回波作了比较。结果表明,雾顶回波高度与逆温和相对湿度的转折高度一致;雾顶回波在雾的成熟期呈现波动,在消散期有一下降过程。上午大气污染物地面浓度的变化与逆温混合层状况有密切关系,混合层较薄且持续时间较长时,地面浓度较大  相似文献   

5.
在简要介绍上海LAP-3000边界层风廓线雷达探测原理和产品生成的基础上,利用近两年来搜集的资料,分析风廓线雷达资料短时强降水、龙卷风等局地强对流天气预报中的应用。结果表明,LAP-3000边界层风廓线雷达资料时间和空间分辨率较高,能有效揭示常规天气资料难以分析的一些大气动力和热力特征,在短时强对流天气预报中有较好的业务应用前景。  相似文献   

6.
为评估云光学厚度(CLDOPD)在空气质量数值模式中对边界层臭氧浓度的模拟影响,利用中国科学院大气物理研究所自主研发的嵌套网格空气质量预报模式系统(NAQPMS),对中国华北京津冀地区2013年6月夏季臭氧浓度进行模拟。结果表明:NAQPMS对极端对流性天气下的CLDOPD模拟偏低,结合观测数据对CLDOPD进行修正后,边界层臭氧浓度的模拟误差在一定程度上有所减小。此外,除极端性天气外模式对高CLDOPD值情况下的边界层臭氧浓度的模拟能力要优于低值情况。  相似文献   

7.
2008年“威马逊”台风期间海上大气波导时空特征   总被引:1,自引:0,他引:1  
结合 MM5数值模拟结果、天气图和卫星云图,系统分析了2008年“威马逊”台风引起的大气波导特征.本次台风过程中发生的大都为悬空大气波导,位于台风涡旋之外的西北部,台风越近波导高度、强度、厚度越大;同时数值模拟表明陆地地形对海上本次大气波导形成具有一定影响.利用大气波导这一特殊大气层结可以很好的评估和预测电磁波传播和海上探测通信系统  相似文献   

8.
大气折射率结构常数(Cn2)是大气中折射率大小的体现,为了改善风廓线雷达(WPR)数据质量,提高WPR数据业务应用的可靠性,对边界层风廓线雷达近1年的实测数据采用归纳对比的方法,分析得到Cn2与温度湿度变化的关系,并总结出成都地区晴朗天气下,四季Cn2量级的变化范围,与理论推导一致.夏天10-12到10-20,春秋10-13到10-20,冬天10-14到10-21,此外,根据降水量大小不同,Cn2提升3到6个量级,获得这些定量的范围,为相关风廓线雷达产品识别提供了方法和依据.  相似文献   

9.
为了长时间、大范围获取水汽数值,利用2005~2008年光学遥感的MODIS近红外、红外水汽产品,以及微波遥感AMSR-E数据,2种方法反演水汽。微波AMSR-E亮温数据采用Merritt N.Deeter(2007)亮温极化差方法,选取18.7GHz和23.8GHz 2个波段,得到AMSR-E升轨、降轨大气水汽数值。以京津冀地区为研究区域,通过地统计相关性分析、时间序列分析、年际间变化分析,可知2种方法4种资料反演的大气水汽数值的R2都达到0.95,时间分布符合中国雨带移动规律,空间分布不均。MODIS数据反演值比AMSR-E值要低,得到2种方法反演水汽的各自优缺点。  相似文献   

10.
本文从大气热力—动力学方程出发,导出形式较为简单的热岛分析解,通过数值试验,讨论了城市热岛强度与影响因子(如平均风速,城市加热量,摩擦效应和大气稳定度等)之间的关系。  相似文献   

11.
12.
S 《山地科学学报》2008,5(1):63-72
Livestock behaviour in the Pyrenees includes free grazing and a long resting period that provokes the accumulation of dung and urine in some places,so-called camping areas. The aims of this study were (i) to analyze any change in floral composition,and in nutritional and chemical contents of plants in a livestock camping area; and (ii) to relate the floral composition with soil chemical properties. In a linear transect,five sampling zones were established,from the centre of the camping area to the surrounding Nardus stricta-dominant pasture. The above ground plant biomass and the topsoil were sampled in each zone with 6 replicates per zone. Plant species were classified and weighed to calculate above ground biomass,nutritional and chemical contents,and Shannon diversity and evenness indices. Additionally,soils were sampled in two periods,at the beginning and at the end of grazing period. Soil available nutrients (nitrate,ammonium,phosphorus,potassium,calcium and magnesium),total nitrogen,organic carbon and pH were measured.
Plant chemical contents (protein,lignin and others) were significantly related to the proportions of grasses,legumes and other plants; so,the protein content is positively correlated with legumes plant biomass while lignin content is negatively correlated with grasses. Both plant and soil nutrients increased linearly towards the centre of the camping area. However,the relationship among plant species richness,diversity and evenness relative to its position along the studied transect was bell-shaped. From the outskirts to the centre of the camping area,plants with low nutrient demand were progressively replaced by those with medium and high nutrients demand and by pioneers.
Nardus stricta-dominant pasture has low plant diversity and plant nutrient content as well as a poor soil nutrient availability. The presence of the camping area introduced patches with more soil nutrients and new species in the large spatial scale. However at a small spatial scale,the strong soil nutrien  相似文献   

13.
Based on the hydrographic data in austral summer during the 22nd Antarctic Expedition of China(2005/2006),some features can be found about the northern margin of Emery ice shelf as follows.The heat content in the surface layer(0-50 m) at the eastern end and the western end of the ice-shelf margin is much higher than that at the middle.The upper mixing-layer depth and the seasonal thermocline depth at the middle of the ice-shelf northern margin are much shallower than those at the both ends.However there is much less difference between the middle and the ends in the bottom layer.The remote sensing photos show that the inhomogeneity in the surface-layer water is closely related to the spatial distribution of the floes and polynia in the area.  相似文献   

14.
Totally more than 500 yeast strains were isolated from seawater, sea sediments, mud of sea salterns, marine fish guts and marine algae. The results of routine and molecular biology identification methods show that nine strains among these marine yeasts belong to Aureobasidium pullulans, although the morphologies of their colonies are very different. The marine yeasts isolated from different marine environments indicate that A. pullulans is widely distributed in different environmental conditions. These Aureobasidium pullulans strains include A. pullulans 4#2, A. pullulans N13d, A. pullulans HN3-11, A. pullulans HN2-3, A. pullulans JHSc, A. pullulans HN4.7, A. pullulans HN5.3, A. pullulans HN6.2 and A. pullulans W13a. A. pullulans 4#2 could produce cellulase and single cell protein. A. pullulans N13d could produce protease, lipase, amylase and cellulase. Both A. pullulans HN3-11 and A. pullulans HN2-3 were able to produce protease, lipase and cellulase. A. pullulans JHSc could secrete cellulase and killer toxin. Both A. pullulans HN4.7 and A. pullulans HN5.3 could yield lipase and cellulase. A. pullulans W13a was able to secrete extracellular amylase and cellulase while A. pullulans HN4.7 and A. pullulans N13d could produce siderophores. This means that different A. pullulans strains from different marine environments have different physiological characteristics, which may be applied in many different biotechnological industries.  相似文献   

15.
NEW TAXA OF EUGLENOPHYTA FROM CHINA   总被引:1,自引:0,他引:1  
Eight new taxa of Euglenophyta are described in this paper. They were collected from severalprovinces in China and respectively named Euglena allorgei var. exsulcata. E pisciformis var. globosa, E.tortiliS, Lepocinclis glabra var. papillata, Phacus pisiformis, Ph.strombuliformis,Ph.trimarginatus var.truncatus and Astasia angusta.  相似文献   

16.
As an important component of the cryosphere,sea ice is very sensitive to the climate change.The study of the sea ice physics needs accurate sea ice thickness.This paper presents an electromagnetic-induction(EM) technique which can be used to measure the sea ice thickness distribution efficiently,and the successful application in Bothnian Bay.Based on the electromagnetic field theory and the electrical properties of sea ice and seawater,EM technique can detect the distance between the instrument and the ice/water interface accurately,than the sea ice thickness is obtained.Contrastive analysis of the apparent conductivity data obtained by EM and the value of drill-hole at same positions allows a construction of a transformable formula of the apparent conductivity to sea ice thickness.The verification of the sea ice thickness calculated by this formula indicates that EM technique is able to get reliable sea ice thickness with average relative error of only 12%.The statistic of all ice thickness profiles shows that the level ice distribution in Bothnian Bay was 0.4-0.6 m.  相似文献   

17.
本文分析了早寒武世单板类Yerhelcionella在世界上几个国家和地区的产出层位及形态特征,认为中国河南的Y.chinensis产出层位最低,形态结构原始,是世界上发现的最古老的Yochelcionella,提出Y.chinensis在河南前次出现,并迁移到澳大利亚Flinders地区生存。西伯利亚的Y.stylifera和北美的Y.americana也可能与河南的Y.chinensis有一定联系。澳大利亚新南威尔士所产Y.cyrano.Y.daleki.Y.ostentata三个高级种与Y.chinensis有着密切的演化关系。此外对Yochelcionella的起源与进化提出见解。  相似文献   

18.
青城子矿田是一个大型金、银多金属综合矿田,矿田内具有(铜)铅锌-银-金的矿化分带现象。从含矿原岩建造-浊积岩建造、变质作用、岩浆作用、韧性剪切作用以及矿质分异作用角度对青城子矿田的矿化分带性做了初步研究,认为青城子矿田的矿化分带性是多种因素造成的。对矿田分带性的研究有利于青城子矿田乃至辽东地区的金、银多金属矿产找矿与勘查。  相似文献   

19.
Chinese meteorological satellite FY-1D can obtain global data from four spectral channels which include visible channel(0.58-0.68 μm) and infrared channels(0.84-0.89 μm,10.3-11.3 μm,11.5-12.5 μm).2366 snow and ice samples,2024 cloud samples,1602 land samples and 1648 water samples were selected randomly from Arctic imageries.Land and water can be detected by spectral features.Snow-ice and cloud can be classified by textural features.The classifier is Bayes classifier.By synthesizing five d ays classifying result of Arctic snow and ice cover area,complete Arctic snow and ice cover area can be obtained.The result agrees with NOAA/NESDIS IMS products up to 70%.  相似文献   

20.
Although both Astasia longa and Euglena gracdlis belong to different genera, they share many morphological characters except that A. longa has no chloroplast. In the 1940‘ s, on the basis of the finding that in darkness or upon addition of scrne chemicals, E. gmcilis would fade reversibly or irreversibly, scrne scholars hypothesised that A. longa evolved from E. gracilis by losing chloroplast.The authors‘ use of RAPD and cladistic analyses in a study on the evolutionary relationship between A .longa and E. gmcilis showed that the A. longa ‘ s relationship with E. gmcilis was closer than that with other green euglenoids. This proves the hypothesis that A. longa evolved from E. gmcills is reasonable. The results d this study suggest that saprophytic colorless euglenoids were transformed fromgreen euglenoids by losing their choroplasts.  相似文献   

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