新一代天气雷达灾害性天气警报和短时预报系统

由中国气象科学研究院主持，北京、湖北、广东、安徽和厦门等省市气象局科研人员参与的以多普勒天气雷达实时观测资料为基础的新一代天气雷达灾害性天气警报和短时预报系统于2006年底完成，建立了一整套回波特征参数定量提取技术、风场反演技术、灾害性天气自动识别技术以及自动和人机交互的0～2h暴雨、大风、冰雹的预报和0～2h降水预报技术。     

向量场的经验正交展开及其应用

本文提出了一种向量场经验正交展开的方法。我们对N×T个离散点上的向量所构成的一个N×T维矩阵,设法寻找一组称为经验正交函数的向量,使其中每一个分量都在均方意义下最接近矩阵的每一列。这组向量可以从特征方程确定。对于有N列元素的矩阵(注意每一个元素都是一个向量),有不少于N个经验正交函数分量。用这些分量所作向量场的正交展开级数收敛很快。给出的展开实际例子说明:向量场经验正交展开,可以比一般标量场经验正交展开,取得更好的效果。     

地面对晴空大气热辐射结构的影响

本文利用1987年美国FIFE资料及1986年6月TIPMEX资料,并利用大气长、短波一维辐射传输数值模式,计算了晴空大气状态下地面辐射参数(地面热辐射温度、地表反照率等)对大气长波冷却率、短波加热率廓线的影响。结果表明,地球表面对大气边界层内的热辐射结构影响很大,特别是在高原地区这种影响尤其显著。     

COMPARISON OF AEROSOL CHARACTERISTICS OVER MAINLAND OF CHINA AND WESTERN PACIFIC AND ITS LONG-RANGE TRANSPORT

Based on the aerosol data obtained at Shangdianzi regional background monitoring station together withthe air trajectory analysis,the chemical constituents of the aerosol from the different sources are discussed andcompared with the aerosol samples collected over the western Pacific.The results show that the relative massconcentrations of the crustal and pollutant elements in the aerosol collected over the ocean are higher than thosebeing observed at Shangdianzi in particle size above 4.7 μm and below 0.65μm in diameter.The variationsof the enrichment factors of these elements in marine aerosol with particle size are different from those in shang-dianzi's samples.The former enrichment factors are evidently higher than the latter above 1.1 μm in diameter.On the basis of the comparative research,the long-range transport processes of aerosol particles are discussed.     

呼伦贝尔草原大气浑浊度的测量和尘埃输送的初步探讨

利用相对日射表和玻璃滤光片,于1974—76年的4—7月份在呼伦贝尔草原进行了大气浑浊度的测量。根据测量结果,研究了半干旱草原尘埃输送的特性。通过不同测点的对比,分析了草原开垦对尘埃输送的影响。     

The uncertainty importance measure of slope stability based on the moment-independent method

Stochastic Environmental Research and Risk Assessment - It is well known that there are many uncertainties in slope engineering, which have great impacts on slope stability models. However, the...     

Analysis of elastic anisotropy of tight sandstone and the influential factors

Tight sandstone has a certain anisotropy. Using ultrasonic measurements of samples in three different directions and related matched experiments, this study systematically analyzes the pore structure and anisotropy of tight sandstone samples obtained from oil fields and compares results with those of shale. Results firstly show that the anisotropy of tight sandstone is mainly related to the compositional layering and thin interbedding which occur in different sedimentary environments. Tight sandstone has typical transverse isotropic medium characteristics, Young’s modulus increases in different directions with increasing confining pressure, Poisson’s ratio change is not obvious, anisotropic coefficients decrease with increasing effective pressure, and a certain linear relationship exists between ε, γ, and δ. This article finally summarizes anisotropy in different areas, thereby providing a foundation for the use of suitable appraisal models in different regions. This research can be used as an experimental reference for logging evaluation, seismic data interpretation, and fracturing develop of tight sandstones.     

地市级城镇天气预报制作及传输系统设计与实现

在城镇精细化预报制作和传输特点及需求分析的基础上,阐述了地市级城镇天气预报制作与传输系统的设计思路、功能实现和系统应用.系统选取PowerBuilder 7.0开发环境,PowerScript可视化编程语言,在Windows 2000操作系统上研制而成.由人机交互、预报自动传输和预报查询3个子系统构成,可制作城镇精细化、短时、评分、城区、城区上下班等多项预报,可随时查询利用该系统制作和传输到本地服务器上的各项预报,可用人工与自动两种方式向省局传输所需的预报.该系统为省级以下气象台的预报员提供了一个可靠、高效的预报制作、传输平台,为预报服务人员提供了一个方便、快捷的预报查询平台.     

西安市近50年来气候变化多时间尺度分析

利用Ｍｏｒｌｅｔ小波变换法分析了西安市近５０年月平均气温距平和月降水量距平变化的多层次时间尺度结构，发现西安市气候变化除１年的自然周期变化和２０－４０年尺度范围的周期变化信号在全时间域中都强小，其它时间尺度的周期变化在时间域中分布很不均匀，具有很强的局部化特征，西安市月平均气温距平变化主要表现为随机振荡，无特征尺度，而月降水量距平变化则有显著的４～５月的时间尺度，西安市气候变化受地理条件的影响较大