Construction of vertical wind profile from satellite-derived winds for objective analysis of wind field

During summer Monex-79, a variety of observing systems viz. research ships, research aircrafts, constant pres-sure balloons and geostationary satellite etc. were deployed, besides the regular conventional observations The pur-pose of these additional systems was to make the best possible data for the studies on various aspects of monsoon cir-culation. The present study is aimed at the construction of vertical wind profile using cloud motion vectors obtained from GOES (I-O) satellite and to examine whether the constructed wind profiles improves the representation of the monsoon system, flow pattern etc. in the objective analysis. For this purpose, climatological normals of the wind field are considered as the initial guess and the objective analyses of the wind field are made with, first using only data from conventional observations over land areas, subsequently including the constructed winds from cloud motion vectors. These analyses are then compared with the standard analyses of wind field obtained from Quick Look Atlas by T. N. Krishnamurti et al. (1979).It is inferred that satellite estimated mean wind profiles show good agreement with the mean wind profiles of the research ships with RMS errors less than 5 mps below 500 hPa and less than 8 mps above 500 hPa. It is further infer-red that the inclusion of constructed winds shows a positive impact on the objective analysis and improvement is seen to be more marked in the data-sparse region of the Arabian sea. Analyses which include the constructed winds show better agreement with the standard analysis, than the analyses obtained using only conventional winds. Thus, results of our study suggest that the wind profiles constructed using cloud motion vectors are of potential use in objective analysis to depict the major circulation features over the Indian region.     

A ROBUST PLS PROCEDURE

A robust partial least squares(PLS)regression algorithm is developed.This is achieved by substitutionof the univariate regression steps in the iterative PLS2 algorithm by a robust alternative.The anglebetween loading vectors from both perturbed and unperturbed solutions is used as a measure ofrobustness.By means of a perturbation study on a structure-activity data set,it is demonstrated thatthe stability of the robust method is superior to standard PLS.     

大陆漂移理论考证：20年代的漂移机制

大多数地质学家听说过阿尔夫雷德·魏格纳和大陆漂移理论。地质学家和历史学家一般认为大陆漂移没有被普遍接受的主要原因是:该理论缺乏恰当的成因机制。然而历史的证据表明,当时曾有好几个很有力的成因解释,尽管如此,大陆漂移仍遭到反对。魏氏理论的成因机制建立在地壳均衡论的推论上。早在19世纪50年代,地壳均衡已被用来解释喜玛拉雅山的重力差异;到20世纪初,更扩展应用于多种地质现象的解释,包括Fennoscandian地区的抬升。均衡补偿,以及Fennoscadian地区的隆起的理论解释是:基底的密度较高、活动性大,陆壳物质能够在其上漂浮。魏格纳认为,如果陆壳能够在这样的活动基底上垂直运动,那么它就同样能够做水平运动。因此,魏格纳面临     

韦帕马努金矿—南印度塔尔瓦克拉通太古宙拉马吉里绿岩带中的脉型金矿化

韦帕马努金矿是安德拉邦阿嫩德布尔内太古宙绿岩带的一个产金矿山。拉马吉里绿岩带是一个南北走向的、线状的(50KM×2-3KM)。以火山岩为主的塔尔瓦尔克拉通东部的分岔状的带。它大部由带枕状构造的变质玄武岩(块状和片状考型)及少量的变辉长岩、绢云母—绿泥石千枚岩、绢云母片岩、绿泥石—阳起石片岩、长石片岩和条带状含铁建造组成。这一带是高度剪切、多期褶皱、达绿片岩相变质作用。此带岩层被粗玄     

干旱区与全球变化——以末次气候旋回为例

目前,我们已获得很多数据,据此可对过去13万年以来亚洲和非洲干旱带气候演化历史与全球变化记录做一对比。在年代学数据可大致对比的前提下,这些气候参数显示出共同变化的特征。它们是:(1)由地球轨道变化引起的太阳辐射变化;(2)海洋表面温度变化;     

一种飓风数值预报的初值化方法

本文使用具有Gallelean变换和详细动量、热量垂直输送通量描述的飓风动力方程组,由切向风速得到垂直运动场、加热场等,结果表明了垂直运动场和加热场具有明显的螺旋雨带特征,温度场有暖心结构及其位势高度场具有深低压特征,这些特征和实际观测结果相吻合。这个方法为飓风数值预报初始场提供了可行的方法。 用数值方法预报飓风的发生发展和路经及降水分布是飓风研究的一种主要方法。但是,对于数值预报飓风的初始场的确定仍是一个没有彻底解决的问题。在过去的初始场处理中,大致分几种,一种是初始场全部采用理想化的低压扰动,另一种则是用实际资料得到环境流场然后再加上一个理想化的     

A limited area model for monsoon prediction

A six level regional primitive equation model has been formulated and tested for monsoon prediction. The model uses dynamic normal mode initialization scheme for obtaining initial balance. The physical processes included are: the large scale condensation, the Kuo type of cumulus convection, the surface friction, the sensible heat supply and evap-oration over the sea. The actual smooth orography is included. The model has been integrated for 48 hrs using input of 7 July and 8 August 1979 when the domain of integration was dominated by an intense monsoon depression. In order to investigate the model simulation of formative stage of the depression, the model was also integrated using input of 4 July 1979.Furthermore, the envelope orography has been constructed and included in the model for investigating its effects on the monsoon prediction. Results of the model forecast are presented and discussed.     

ESTIMATION OF VERTICAL DISTRIBUTION OF RELATIVE HUMIDITY USING SATELLITE DATA

In this paper,an attempt has been made to find out the vertical distribution of RH at levels of 850,700 and 500 hPa by using satellite-derived radiation parameters (i.e.,albedo,outgoing longwave fluxes,absorbed solar radiation and net radiation).For this purpose,multiple regression equations are derived from MONEX-79 upsonde and dropsonde data over the Arabian Sea for the period 11-20 June 1979.Satellite-estimated RH fields have been compared with ECMWF RH fields obtained from FGGE level ⅢB data.The RMS error and error variance for satellite-estimated RH fields have been found to be less than for those of ECMWF.Satellite-estimated isohygric patterns show good agreement with the cloudiness patterns of GOES satellite,whereas ECMWF isohygric patterns do not show much resemblance with the cloudiness patterns.The results of the study suggest that satellite-estimated RH fields could be more useful than ECMWF RHfields and they can be used with some confidence in NWP models.