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111.
北上热带气旋发展与不发展的对比分析   总被引:2,自引:0,他引:2       下载免费PDF全文
重点分析了一个北上热带气旋(8509号台风)变性发展过程中扰动能和扰动有效有效位能的收支平衡关系及其与中纬地区高空环境场、Q矢量散度、旋度特征和锋生锋消现象的联系,并和与此台风前期路径及强度相似、但进入西风带后很快消失了的8406号台风的诊断结是要 进行了对比。结果表明:有利的大尺度环境是台风变性发展的主要因子和先决条件,斜压过程是否能有效和大量地制造扰动动能以抵消台风北上过程中的能量耗散是其能否  相似文献   
112.
本文根据地壳中间界面上反射波的运动学和动力学参数,探测了地壳中间界面的埋深、复盖介质中波的传播速度、温度、压力、反射性、透过性、弹性等性质。  相似文献   
113.
东海陆架盆地岩石密度与磁性   总被引:9,自引:0,他引:9  
本文在东海陆架盆地20口钻井160块岩心标本物测定和17口钻井密度测井的基础上,通过整理、分析、统计,给出了东海陆架盆地的岩石密度和磁性特征。  相似文献   
114.
Observations taken by aircraft and conventional platforms are used to investigate dynamical, physical, and radiative processes within a marine stratus cloud during the Canadian Atlantic Storms Program (CASP) II field project which took place over the east coast of Canada. Stratus which formed over the ocean on February 6, 1992 during the nighttime, is studied to analyze cloud top and base processes. The cloud was supercooled during the study period. Fluctuations and fluxes are calculated along constant flight altitude legs approximately 100 km long in space. The scales of structures larger than 5 km are removed from the analysis using a running average technique. Droplet spectra obtained by a forward scattering spectrometer probe (FSSP) were used in a 1-D radiative transfer model to calculate infrared (IR) fluxes and radiative heating rates. A heat conservation equation was used to estimate vertical air velocity (w a ) within the cloud. The results showed that, because of a warmer ocean surface, significant moisture and heat were transferred from the ocean surface to the boundary layer. The cloud base was at about 400 m height and the top was at about 1.4 km.w a at the cloud base was estimated about 5 cm s–1. Strong IR cooling rate at the cloud top was calculated to be 75°C day–1 for a 100 m thick layer. Negative skewness inw a , suggesting narrow downdrafts, was likely due to radiative cooling at the cloud top. The entrainment velocity was found to be about 1.5 cm s–1 at cloud top. Mean moisture and heat fluxes within the cloud were estimated to be comparable to those from the ocean surface. Vertical air velocity at the cloud top due to radiative cooling was found to be about –40 cm s–1.  相似文献   
115.
暴雨类冷涡与非暴雨类冷涡的合成对比分析   总被引:15,自引:2,他引:15       下载免费PDF全文
孙力  王琪  唐晓玲 《气象》1995,21(3):7-10
选择了8例典型的东北冷涡暴雨过程和8例典型的东北冷涡弱降水过程进行了合成对比分析,发现暴雨类冷涡其暴雨主要出现在冷涡的发展阶段,而非暴雨类冷涡的降水主要发生在冷涡的成熟阶段;暴雨类冷涡与其南侧的副热带低值系统联系密切,非暴雨类冷涡的这一特点不甚明显;暴雨类冷涡的两个降水中心分别出现在系统东侧偏南和南侧偏东一些的地,距系统中心大约300-400km和700-800km,这些区域处于低层辐合、高层辐菜  相似文献   
116.
The Andhra severe cyclonic storm (2003) is simulated to study its evolution, structure, intensity and movement using the Penn State/NCAR non-hydrostatic mesoscale atmospheric model MM5. The model is used with three interactive nested domains at 81, 27 and 9 km resolutions covering the Bay of Bengal and adjoining Indian Peninsula. The performance of the Planetary Boundary Layer (PBL) and convective parameterization on the simulated features of the cyclone is studied by conducting sensitivity experiments. Results indicate that while the boundary layer processes play a significant role in determining both the intensity and movement, the convective processes especially control the movement of the model storm. The Mellor-Yamada scheme is found to yield the most intensive cyclone. While the combination of Mellor-Yamada (MY) PBL and Kain-Fritsch 2 (KF2) convection schemes gives the most intensive storm, the MRF PBL with KF2 convection scheme produces the best simulation in terms of intensity and track. Results of the simulation with the combination of MRF scheme for PBL and KF2 for convection show the evolution and major features of a mature tropical storm. The model has very nearly simulated the intensity of the storm though slightly overpredicted. Simulated core vertical temperature structure, winds at different heights, vertical winds in and around the core, vorticity and divergence fields at the lower and upper levels—all support the characteristics of a mature storm. The model storm has moved towards the west of the observed track during the development phase although the location of the storm in the initial and final phases agreed with the observations. The simulated rainfall distribution associated with the storm agreed reasonably with observations.  相似文献   
117.
单站气象要素剖面图是日常预报业务中经常使用的工具之一。计算机绘制剖面图可做到快捷、美观和自动化,且能克服纸质剖面图存储中的诸多弊端,适宜长期保存。广州市单站要素及特征曲线显示系统除把纸绘剖面图的内容搬到屏幕外,还增加了一些物理量。系统可实时显示广州五山站、四个县级市、清远探空站、衡山站的基本资料,显示气压、温度、湿度等观测要素或清运探空站物理量的时间演变曲线。系统用VB5.0编写,目前已在业务上使用,成为广州市短期预报的一个参考工具。  相似文献   
118.
通过研究国内外各类银矿床地质资料中银矿石的共生矿物组成,得出了各类银矿床的基本物性特征,为合理选择银矿物探的有效方法提供了依据;引述和分析了银矿物探取得显著效果的若干实例,说明合理的综合找矿方法在银矿找矿中的巨大潜力有待发挥。  相似文献   
119.
Analysis of physical properties in long sediment cores (BDP96) from Academician Ridge in Lake Baikal indicates that major climato-limnological changes during the past 3.5 Myr occurred at about 2.5–2.8, 1.7–1.9, and 0.9–1.2 Ma, which were close to times of major geomagnetic polarity reversals (Matuyama/Gauss, Olduvai, Jaramillo + Matuyama/Brunhes). The principal climato-limnological oscillation has a long-term period of nearly 1,000 kyr, which corresponds to the periodicity of fluctuation in solar insolation. It also seems to be related to geomagnetic field intensity. Other long-term period of 400 kyr corresponds to Milankovitch parameters of eccentricity. These results suggest that changes in solar insolation were closely related to long-term environmental variations in the deep continental interior.  相似文献   
120.
直流电法在探测老窑采空区的应用   总被引:1,自引:1,他引:1  
在各种工程地质、环境地质中、对地下采空区的探测是地球物理勘探的一项重要内容。文章从物性参数研究、技术方法择方面入手,探讨了直流电法探测老窑采空区的可行性,并以实例介绍了解决该问题所取得的经验。  相似文献   
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