NUMERICAL SIMULATION OF TROPICAL CYCLONE MOVEMENT WITH THE RELATED CRITICAL POINT PHENOMENON

A study is made of the paths of tropical cyclones under the joint action of environmental flow and heating fields interms of a quasi-geostrophic barotropic model with the thermal forcing and dissipation terms involved,in which 16 ex-periments are designed and integrated for more than 7 model days.Results show that for different parameter values ofthe environmental flow and heating field,and the cyclone scale, such paths as counterclockwise looping, zigzag form andwestward march with an abrupt turning towards the north are reproduced clearly in the model atmosphere,exhibitingtheir critical points of nonlinear character.     

深层水泥搅拌在高速公路地基处理上的应用

深层水泥搅拌在高速公路地基处理上的应用先泽祥（中国水利水电基础工程局，天津３０１７００）深层水泥搅拌自７０年代从日本引进后，在我国的港口、民用建筑等软基处理项目上得到了广泛的应用，收到了较好的经济和社会效益。但能否应用在高速公路的地基处理上，专家们是...     

模糊数学方法在边坡稳定性评价中的应用

作者根据对甘肃黄土地区的滑坡研究,确定了影响黄土边坡稳定性的六种主要因素。试用模糊数学方法对这些因素逐项进行分析,找出促使边坡变形的“有害成分”。在单项评价的基础上再进行了综合评价。     

ABRUPT CHANGE OF FLOW PATTERN IN BAROCLINIC ATMOSPHERE FORCED BY JOINT EFFECTS OF DIABATIC HEATING AND OROGRAPHY

Based on the catastrophic theory, the possible causes of abrupt change in the atmospheric circulation over the Northern Hemisphere during June and October have been explored by Li and Luo (1983) and Miao and Ding (1985). However these studies are confined to the barotropic atmosphere without consideration of orography. The purpose of this paper is to further study the physical mechanism of the abrupt change of flow pattern within the baroclinic atmosphere in the presence of orography. Results show that the abrupt change of flow pattern can be stimulated by the gradual variation of a diabatically heating parameter, which is similar to the observed fact about the rapid shift of position of the subtropical high center in the upper troposphere along the zonal direction during seasonal transition from the summer half year to the winter one.     

一个以全露点温度为湿度变量的低谱湿模式

(一)1.研究古气候和气候变迁问题的一个有力的途径是实施数值试验。目前,在数值模拟试验中,广泛地使用了大气环流模式(GCM)。对气候平均场和短期气候变化的模拟取得了引人注目的结果。这些显示了 GCM 广泛应用的前景。2.无论是谱展开,还是差分方法,基本方程组都被转化为一个强迫耗散的自治的或非自治的非线性系统。古气候和气候变迁的问题,是气候学的课题。当我们用数值模拟的途径去     

中亚:地震图上最令人不安的地区

1983年12月最后的一天,来自帕米尔—兴都库什地震活动区深部的强震波传播了由阿富汗到哈萨克斯坦好几百公里的范围,在塔吉克斯坦首府杜尚别,地震强度达到六～七度。从瓶中晃出来的杜松子酒,实际上每天都在提供着信息。1984年的头两个月,在塔吉克斯坦、吉尔吉斯和乌兹别克斯坦共发生了约50次有感地震,其中有几次强震,幸而只破坏了一些旧建筑物,没有造成人员死亡。这期间,只有杜尚别地震台记录到了2500多次地震,其中有许多次发生在苏联境内。     

我国半干旱地区降水量序列信噪比分析

本文提出降水量序列信噪比的概念,分析了我国半干旱区降水量序列信噪比的空间分布及代表站点信噪比取值随时间的变化特征。     

青岛地区冰雹天气的短期预报

本文以“山东冰雹预报研究”一文中所总结出的影响我省降雹天气的环流形势及天气分型为基础,再结合青岛十一年(1978—1988年)冰雹天气资料,对青岛冰雹天气的短期预报问题做了初步探讨,现总结如下。 一、青岛冰雹的短期预报     

台风移动准地转正压模式计算方案精度检验的一种方法

本文根据台风能量频散生成系统的对称性质，提出了一种台风移动数值模式计算方案精度检验的方法，并给出了计算的实例。     

Research on changes and circulations of sea-ice in Eurasian in recent 50 years

Using the monthly 1°×1°sea-ice concentration data of Hadley center and the monthly NCEP geopotential height data from January 1953 to February 2003,temporal and spatial changing characters of sea-ice are examined.The results show almost all of the sea-ice of eight regions was decreasing,especially all s easons in Europe.But in Asia part,those display some increasing trends in spri ng and winter.Abrupt times of sea-ice in Europe were at end of 1970's and in Asia the times in summer/fall(spring/winter)were at end of 1980's.