Climatic characteristics of convective and stratiform precipitation over the Tropical and Subtropical areas as derived from TRMM PR   总被引：4，自引：0，他引：4  

LIU Peng  LI ChongYin  WANG Yu  FU YunFei 《中国科学:地球科学(英文版)》2013,(3):375-385

Climatic characteristics of convective and stratiform precipitation over the Tropical and Subtropical areas are investigated based on the measurements of Tropical Rainfall Measuring Mission’s(TRMM) Precipitation Radar(PR) from 1998 to 2007.Results indicate that convective precipitation are distributed mainly over the Intertropical Convergence Zone(ITCZ),the South Pacific Convergence Zone(SPCZ),the Asian Monsoon Region,regions between the South America and the Mid-America,and the Tropical Africa where the frequencies lie between 1% and 2%.But in four seasons,total area fractions of convective precipitation frequencies less than 1% all exceed 85%.The frequencies of stratiform precipitation are much higher than those of convective precipitation,and total area fractions of stratiform precipitation frequencies >1% are over 55% during four seasons.However,frequencies of the two rain types show not only remarkable regionality,but also distinct seasonal variations.Conditional rain rates of convective precipitation range from 6 to 14 mm/h whereas those of stratiform precipitation are smaller than 4 mm/h.Meanwhile,rain tops of convective precipitation are higher than those of stratiform precipitation.The mean profiles of the two rain types show significant latitudinal dependency.And the seasonal variations of precipitation profiles are displayed mainly in the variations of rain tops.The frequencies and conditional rain rates of both rain types over ocean are higher than those over land,but rain tops are just the opposite.Moreover,the seasonal variations of both rain types over ocean are weaker than those over land because of the different stable states of underlying surfaces.  相似文献   

Physics of Seismic Source Ⅲ. Statistical Mechanics of Earthquakes     

Chen Yuntai  Wu ZhongliangInstitute of Geophysics  CSB  Beijing  China 《中国地震研究》1999,(2)

The statistical mechanics of earthquakes adopts the concepts and methodology of statistical mechanics, especially the theory of critical phenomena, in studying the preparation, initiation, propagation and healing of earthquake rupture, which forms a new branch in the physics of seismic source in recent years. This article introduces to the fundamental concepts of the statistical mechanics of earthquakes. The introduction includes the seismic Hamiltonian, percolation model, earthquake rupture nucleation, and Burridge-Knopoff spring-block model. It is pointed out that some of the statistical mechanical models of earthquakes have a sound seismological basis. There is a smooth "transition" from the "classical" theory to the "modern" theory of seismic source.  相似文献   

地震动力分析的经典方法与现代计算技术     

万召侗  姚运生 《大地测量与地球动力学》2004,24(1):111-116

回顾了体系地震动力分析的历史过程，并对地震动力分析的传统理论方法、近似方法和现代计算技术从新的角度加以阐述，同时给出体系地震动力分析的应用前景，以促进经典的传统理论方法、近似方法和现代计算技术的综合和在实际工程中的应用，形成系统而完整的地震动力分析体系。  相似文献   

IAG2001年科学大会与大地测量学的最新进展     

胡建国  杨元喜  李建成  李金岭 《大地测量与地球动力学》2002,22(4):112-119

扼要报导了国际大地测量学术界的一次重要会议－IAG2001年科学大会。根据会议的学术报告，对坐标系统的统一与协调，全球重力场研究，导航卫星的应用，地壳形变与地球动力学等方面的研究进展作了详细介绍。  相似文献   

长江三峡库区地震地形变监测研究   总被引：8，自引：4，他引：4  

杜瑞林  邢灿飞  伍中华  李胜乐  乔学军  游新兆  王琪  孙少安  申重阳  凌模 《大地测量与地球动力学》2004,24(2):23-29

三峡地壳形变监测网络结合空间大地测量(GPS、InSAR)和传统大地测量的优点，在1998年以来的三峡工程建设期间和2003年水库首次蓄水中获取了大量监测成果。结果显示库区地壳运动的基本图像：垂直形变较为显著，主要来自因蓄水荷载而产生的形变，水平形变不明显．库区主要断层的活动性在蓄水期间有明显加强迹象。水准测量反映从1998年首期观测至2003年10月首次蓄水后的库区垂直位移．沉降范围较大；GPS给出了2003年蓄水前后库区的垂直位移，形变的范围主要集中在水库近岸区域。水准测量与GPS观测反应的垂直位移的量级基本一致，沉降的最大幅度在3～4cm左右。水准监测、GPS观测与重力监测结果有一定的对应性。从地壳形变监测与研究结果分析，近期负荷改变而诱发中强地震的可能性不大。  相似文献   

香山绝对点周围的局部地壳变形及其对重力测量结果的影响   总被引：1，自引：0，他引：1  

刘少明  高荣胜  贾民育 《大地测量与地球动力学》2002,22(2):97-100

为了监视北京地区的地壳稳定性，北京测绘院对10多个基岩点和北京市区进行了多次沉降观测，结果表明香山点近10多年来高程变化只有几毫米，其重力效应可略而不计，但测点东北和东南方有两个较大的下沉区。用线积分法计算了两个局部沉降的重力效应，在沉降区中心其影响可达0.38μms^-2，但对香山点的重力效应非常小，完全可以忽略。因此得出如下结论：香山点观测到的重力变化不是地壳变形引起的。  相似文献   

浅议矿业权转让市场建设与地勘行业改革的关系     

蒋辉杰 《青海国土经略》2001,(1)

笔者从地勘单位由事转企改革的角度,分析论证矿业权转让市场建设的迫切性,并对矿业权转让市场建设中有关的交易对象、矿业权价值认定、矿业权利益取得以及市场的启动与运作等问题,提出了一些具体的意见,使该市场真正对地勘改革和社会主义市场经济建设起到积极地促进作用。  相似文献   

大坂山含“铬矿物”石英闪长岩岩石特征     

韩英善  陆海莲 《青海国土经略》2001,(2)

大坂山“铬矿物”产出于灰绿色中细粒石英闪长岩中,笔者从区域地质特征、岩石学、岩石化学、地球化学、同位素等方面对石英闪长岩进行了较全面的研究后认为,该套岩石成因为壳幔混合型,构造环境为北祁连加里东洋盆收缩阶段板块俯冲作用下形成的火山弧,岩石成岩时代为早奥陶世,铬矿物形成深度约30km,受区域性岩石圈断裂带控制。  相似文献   

The Hybrid Nature of 0846＋51W1： a BL Lac Object with a Narrow Line Seyfert 1 Nucleus     

Hong-Yan Zhou  Ting-Gui Wang  Xiao-Bo Dong  Cheng Li  Xue-Guang ZhangCenter for Astrophysics  University of Science  Technology of China  Hefei   《中国天文和天体物理学报》2005,5(1):41-48

We found a NLS1 nucleus in the extensively studied eruptive BL Lac object, 0846+51W1, out of a large sample of NLS1s compiled from the spectroscopic dataset of SDSS DR1. Its optical spectrum can be well decomposed into three components: a power law component from the relativistic jet, a stellar component from the host galaxy, and a component from a typical NLS1 nucleus. The emission line properties of 0846+51W1, FWHM  相似文献   

A TAXONOMICAL AND ECOLOGICAL SURVEY OF ROTIFER COMMUNITIES IU KROTTENSEE (AUSTRIA)     

诸葛燕 《中国海洋湖沼学报》1996,(4)

The composition and distribution of benthic, periphytic and planktonic rotifers in different habitatsin Krottensee were investigated. Sixty-five rotifer taxa were identified, their relative abundance estimated. Classification of the data set by cluster analysis allowed the recognition of distinct habitat groupe con-fined to acid bog ponds, macrophytes, sediments, and open water. Five groups of rotifer taxa were identifiedon the basis of their habitat preferences and the occurrence of the taxa. Highest diversities were found onmacrophytes and in acid bog ponds.  相似文献