青藏高原近地层通量特征的合成分析   总被引：17，自引：0，他引：17  

李国平  段廷扬  巩远发  卢会国 《气象学报》2002,60(4):453-460

利用中日亚洲季风机制合作研究计划 ,设置在青藏高原东部地区的拉萨、日喀则、那曲和林芝 4地 1993年 7月～ 1999年 3月近 7a的自动气象站 (AWS)近地层梯度观测资料 ,确定出分季节的高原地表粗糙度和逐日的地面总体输送系数 ,以此为基础用总体输送公式对地面动量、感热和潜热通量进行了计算 ,并用合成方法分析了 1993～1999年高原近地层通量夏季、冬季的日变化和月变化特征  相似文献   

中尺度模式中的边界层特征量分析     

许丽人  赵鸣  汤剑平 《高原气象》2002,21(2):145-153

在中尺度数值天气预报模式MM4中，用level3及E-ε-l两种湍流闭合方法对原总体边界层参数化方案进行改进，使得中尺度模式中可以直接输出有关湍流量，并对地表通量参数化方案进行改进，进而对不同下势需如沙漠，植被上的有关湍流量和边界层特征量进行分析。研究中尺度系统中边界层结构的特征，本文主要从地表通量，湍流交换系数，湍流动能（q^2)，温度脉动方差（θ^2)及风温廓线等几个方面进行研究，结果表明，新方案能更好地反映边界层特征。  相似文献   

青藏高原地面-对流层系统的能量收支   总被引：3，自引：3，他引：3  

沈志宝  成天涛  王可丽 《高原气象》2002,21(6):546-551

利用CCM3中的辐射模式CRM，计算了1月和7月地－气系统、地面－对流层系统和地面辐射能收支，研究了青藏高原地面－对流层系统辐射能收支的冬、夏季节特征及其与地面和地－气系统辐射能收支的关系，并与东部平原地区和高原北侧干旱地区比较。文中还讨论了云和高原冬季地面积雪对辐射能收支的影响，比较了大气辐射加热和地面感热通量对夏季高原对流层大气加热的贡献。  相似文献   

GPS观测在气象中的应用     

张晋  张阿丽 《沙漠与绿洲气象(新疆气象)》2002,25(4):21-23

简述了GPS的组成及发展概况，以及如何利用地面GPS观测探测大气可降水汽量（PWV），从而可以得到高精度，几乎连续和实时的水汽序列，骤报降水量以及监测恶劣天气，为天气预报和气候分析作出贡献。  相似文献   

Hindsight and Foresight     

N. E. Busch  L. Kristensen 《Boundary-Layer Meteorology》2002,105(3):369-388

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Laboratory Studies Of Wind Stress Over Surface Waves   总被引：4，自引：0，他引：4  

B. Mete Uz  Mark A. Donelan  Tetsu Hara  Erik J. Bock 《Boundary-Layer Meteorology》2002,102(2):301-331

Simultaneous laboratory observations of wind speed, wind stress, and surfacewind-wave spectra are made under a variety of wind forcing patterns using cleanwater as well as water containing an artificial surfactant. Under typical experimentalconditions, more than half of the total stress is supported by the wave-induced stressrather than by the surface viscous stress. When the surfactant reduces the shortwind-wave spectra, the wind stress also decreases by as much as 20–30% at agiven wind speed. When the wind forcing is modulated in time, the wind stresstends to be higher under decreasing wind than under increasing wind at a givenwind speed, mainly because the response of short wind-wave spectra to varyingwind forcing is delayed in time. These examples clearly demonstrate that therelationship between the wind speed and the wind stress can be significantlymodified if the surface wave field is not in equilibrium with the wind forcing.Next, we examine whether the wind stress is estimated accurately if the wave-inducedstress by all surface wave components is explicitly evaluated by linear superpositionand is added to the surface viscous stress. It is assumed that the surface viscous stressis uniquely related to the wind speed, and that the wind input rate is determined by thelocal, reduced turbulent stress rather than the total stress. Our wind stress estimatesincluding the wave contributions agree well with observed wind stress values, evenif the surface wave field is away from its equilibrium with the wind in the presenceof surface films and/or under time-transient wind forcing. These observations stronglysuggest that the wind stress is accurately evaluated as a sum of the wave-induced stressand the surface viscous stress. At very high winds, our stress estimates tend to be lowerthan the observations. We suspect that this is because of the enhancement of wind stressover very steep (or breaking) short wind-waves.  相似文献   

Determination of Area-Averaged Water Vapour Fluxes with Large Aperture and Radio Wave Scintillometers over a Heterogeneous Surface – Flevoland Field Experiment     

W. M. L. Meijninger  A. E. Green  O. K. Hartogensis  W. Kohsiek  J. C. B. Hoedjes  R. M. Zuurbier  H. A. R. De Bruin 《Boundary-Layer Meteorology》2002,105(1):63-83

A large aperture scintillometer (LAS) andradio wave scintillometer (RWS)were installed over a heterogeneous areato test the applicability of the scintillation method.The heterogeneity in the area, whichconsisted of many plots, was mainly caused bydifferences in thermal properties ofthe crops; the variations in theaerodynamic roughness lengthwere small. The water vapour fluxesderived from the combined LAS-RWSsystem, also known as the two-wavelengthmethod, agreed fairly well with the aggregatedwater vapour fluxes derived from in-situeddy covariance measurements. The water vapourfluxes derived from a stand-alone LASare also presented. It was found that a single LASand an estimate of the area averagedavailable energy (using a simple parameterisationscheme) can provide also reasonablearea-averaged water vapour fluxes.  相似文献   

成像雷达干涉测量数据相关性与干旱-半干旱地区地表类型特征的关系     

廖静娟  邵芸  郭华东  N.Veneziani 《地球科学进展》2002,17(5):648-652

利用欧洲资源卫星1号和2号获取的重轨干涉测量雷达数据，首先进行干涉测量数据相关性估测，并结合干涉测量数据的振幅信息，开展新疆喀什试验区地表土地类型的识别与分类，区分和识别出裸土、盐碱地、灌丛、裸岩/戈壁、沼泽和水体 6类土地类型。最后通过对不同土地类型的后向散射特性和相关性的分析，探讨了干涉测量数据相关性与干旱-半干旱地区地表特征的关系。  相似文献   

Une méthode de quantification de la dégradation d'un escarpement de faille au cours des cycles climatiques du Quaternaire : la faille de Jobourg (Nord Cotentin,France)Quantification of a fault-scarp degradation through Quaternary: the Jobourg fault (North Cotentin,France)     

Marianne Font  Jean-Louis Lagarde  Daniel Amorese  Jean-Pierre Coutard  Jean-Claude Ozouf 《Comptes Rendus Geoscience》2002,334(3):171-178

The degradation of the Jobourg fault-scarp occurred by cryoclastic processes in a periglacial environment during a part of Quaternary time. An attempt of quantification indicates a bulk scarp erosion of about 39 m³ m^?2, while the head accumulated at the bottom of the fault scarp only represents 4.6 m³ m^?2. To cite this article: M. Font et al., C. R. Geoscience 334 (2002) 171–178.  相似文献   

昆仑山口西8.1级地震地表破裂的类型与性质   总被引：12，自引：0，他引：12  

王赞军  党光明  张瑞斌  张启胜  都昌庭 《高原地震》2002,14(1):17-25

通过对昆仑山口西8．1级地震地表破裂全带的考察认为：本次地震形成的地表破裂带长达350－400km，由地震裂缝，鼓梁（包）、塌陷、陡坡等基本形态组成，属构造性破裂，并具有明显的继承性和新生性。  相似文献