珠峰地区大气边界层结构的一次观测研究   总被引：5，自引：15，他引：5  

孙方林  马耀明  马伟强  李茂善 《高原气象》2006,25(6):1014-1019

利用2005年8月31日~9月5日中国科学院珠穆朗玛峰综合观测研究站的LAP3000风廓线仪的观测资料,分析了该地区气温日变化和大气边界层风廓线结构。结果表明,该地区1500 m以下大气边界层主要受高原山地地形及珠峰地区冰川环境的影响,冰川风可能是引起观测期间下午强风天气的主要原因;1500 m以上高空受西风气流影响程度增大,但东南风仍占有一定比例。  相似文献   

THE ANALYSIS OF THE RELATIONSHIP BETWEEN PULSE OF LLJ AND HEAVY RAIN USING WIND PROFILER DATA   总被引：1，自引：1，他引：1  

刘淑媛  郑永光  陶祖钰 《热带气象学报(英文版)》2003,9(2):158-163

1 INTRODUCTION With the principle of Doppler effect, the wind-profiler acquires high-resolution vertical wind profiles every few minutes and every few dozens of meters[1, 2]. In contrast, data obtained with conventional soundings do not reflect the true conditions right over the sounding site, for the balloons are going with the wind in upper levels. The National Oceanic and Atmospheric Administration, U.S.A., made a final assessment of the wind-profiler networks deployed in central …  相似文献   

Acoustic Doppler current profiler surveys along the Yangtze River     

Zhongyuan Chen  Dechao Chen  Kaiqin Xu  Yiwen Zhao  Taoyuan Wei  Jing Chen  Luqian Li  Masataka Watanabe 《Geomorphology》2007,85(3-4):155

An acoustic Doppler current profiler is used to characterize the river velocity against the morphology of the Yangtze River from Chonqing to the sea. High flow velocities occur in the Three Gorges section and lower velocities in the middle and lower reaches of the river. This is largely due to the change in river pattern from a high gradient deeply-cut valley to a flat fluvial plain. Flow velocities fluctuate in the middle Yangtze due to the presence of meander bends of different length. There are numerous smaller velocity fluctuations in the lower Yangtze channel that reflect multichannel pattern with numerous sand bars and a river morphology affected by bedrock outcrops. Water depths of 40–100 m occur in the Three Gorges valley but decrease to 15–40 m in the middle and lower Yangtze. At the Gezhou Reservoir, 30 km downstream of the Three Gorges damsite velocity drops to low (< 1.0 m s^− 1) 20 km reach. A second low velocity (< 0.5 m s^− 1) zone, about 20 km in length, is located in the lower Yangtze near the coast probably due to the tidal influence. The results from this research will serve as a datum for evaluating changes to the river once the Three Gorges dam is completed in 2009.  相似文献   

云的垂直速度特征分析及人工影响天气作业措施探讨     

袁野  王成章  张苏 《气象科学》2007,27(5):502-509

利用2002年5—7月肥西风廓线仪资料结合常规地面观测资料,对出现各种云时的垂直速度特征进行了分析,在此基础上提出了人工影响天气作业的一些具体措施,希望对云的研究和人工影响天气作业提供帮助。  相似文献   

珠峰地区雨季对流层大气的特征分析   总被引：3，自引：1，他引：3  

陈学龙  马耀明  孙方林  李茂善  王树舟 《高原气象》2007,26(6):1280-1286

利用2007年7月中国科学院珠穆朗玛峰综合观测站的边界层塔、无线电探空和风温廓线仪观测资料,分析了珠穆朗玛峰地区雨季低层大气风温湿等特征.珠峰地区雨季近地层风速、风向、温度等有明显的日变化.近地层风的日变化有两个很明显的阶段,00:00～14:30受谷风的影响而刮偏北风,14:30～24:00受冰川风的影响以偏南风为主.白天的冰川风比夜间的谷风要强些.中午13:30在600m以下存在强水平风速垂直切变,这可能是珠峰地区发生降雨的重要原因之一.低空急流在夏季比较常见.对流层平均降温率为0.685K/100m.低层大气的相对湿度一般有两个峰值高度,最大值在4000m以下,第二峰值高度不固定,到16000m以后相对湿度超不过10%.各层大气的风速风向差别较大.  相似文献   

深圳LAP-3000型风廓线雷达系统及应用   总被引：1，自引：0，他引：1  

陈元昭王小勇  王明洁胡娟 李辉 《广西气象》2007,28(3):73-76

介绍风廓线雷达的历史、LAP-3000型风廓线雷达的基本原理以及深圳市LAP-3000型风廓线雷达的数据存贮格式、风廓线雷达产品的显示等内容;并给出了几种典型风场在风廓线上的反映及对一次冷空气过程的分析。  相似文献   

国内外CTD校准实验室及校准技术研究的现状和展望     

于厚隆  贾肇基 《海洋技术学报》2000,19(1):32-41

本文在叙述ＣＴＤ剖面仪和传感器校准方法的基础上,介绍了当前国内外ＣＴＤ校准技术研究和校准设备的现状。提出了我国应加强ＣＴＤ传感器动态校准的研究,同时,应研制精度慢温盐水盐力罐,用于在实验室内研究建立ＣＴＤ传感器数学模型的方法。  相似文献   

Analysis of the Microphysical Properties of a Stratiform Rain Event Using an L-Band Profiler Radar   总被引：2，自引：0，他引：2       下载免费PDF全文

RUAN Zheng  MING Hu  MA Jianli  GE Runsheng  BIAN Lingen 《Acta Meteorologica Sinica》2014,28(2):268-280

This paper investigates spatial and temporal distributions of the microphysical properties of precipitating stratiform clouds based on Doppler spectra of rain particles observed by an L-band profiler radar.The retrieval of raindrop size distributions（RSDs） is accomplished through eliminating vertical air motion and isolating the terminal fall velocity of raindrops in the observed Doppler velocity spectrum.The microphysical properties of raindrops in a broad stratiform region with weak convective cells are studied using data collected from a 1320-MHz wind profiler radar in Huayin,Shaanxi Province on 14 May 2009.RSDs and gamma function parameters are retrieved at altitudes between 700 and 3000 m above the surface,below a melting layer.It is found that the altitude of the maximum number of raindrops was closely related to the surface rain rate.The maximum number of large drops was observed at lower altitudes earlier in the precipitation event but at higher altitudes in later periods,suggesting decreases in the numbers of large and medium size raindrops.These decreases may have been caused by the breakup of larger drops and evaporation of smaller drops as they fell.The number of medium size drops decreased with increasing altitude.The relationship between reflectivity and liquid water content during this precipitation event was Z = 1.69×10~4M~（1.5）,and the relationship between reflectivity and rain intensity was Z = 256I~（1.4）.  相似文献   

船载ADCP资料处理          下载免费PDF全文

吴云帆  吴中鼎  李占桥 《海洋测绘》2014,34(6):36-39,42

通过对大量走航ADCP观测资料的分析,提出一整套的ADCP资料质量控制和预处理方法,并对提出的ADCP"基准流速控制"的处理方法与传统的"选取参考层法"进行了比较,证明此方法不但可有效提高ADCP资料的处理精度,并可提高资料的处理效率,减少人为的干预因素。  相似文献   

海河流域切变线类暴雨成因分析     

卢焕珍  刘一玮  张楠 《气象与环境学报》2014,30(1):15-22

应用常规观测资料、FY2C卫星TBB资料、多普勒雷达资料、风廓线雷达、加密自动站以及NCEP1°×1°再分析资料分析海河流域切变线类暴雨成因。结果表明：暴雨过程是低空切变线与高低空急流构成有利配置条件下发生的, 系统空间结构和冷空气移动路径的不同,造成了暴雨落区和强度的不同;沿切变线有带状中-α尺度对流云团形成和发展,并有中-β尺度MCS沿带状有组织的发展、移动、合并、加强,沿低空切变线如有低涡形成,带状对流云系内将有MCC形成,强降雨在MCS或MCC移动方向的前侧、TBB等值线梯度最大处;强降雨之前都有水汽辐合从地面向高层伸展,伸展高度越高,降雨强度越大,强降雨中心对应西南与偏东两个大水汽通量造成的辐合且等值线密集处;VAD风廓线和风廓线雷达资料都显示出对流层低空急流和超低空急流的先后形成,造成雨强也两度加强。  相似文献