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461.
Comparison of different land-surface perturbation methods in short-range ensemble forecasts
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Zhibo Gao Jiangshan Zhu Yan Guo Xiaodong Yan Xiujuan Wang Huoqing Li Shuwen Li 《大气和海洋科学快报》2021,14(3):60-65
为了比较不同陆面扰动方法对短时集合预报的影响,本研究设计了陆面模式扰动实验(LSMPE),初始土壤湿度扰动实验(ISMPE),陆面-大气耦合系数扰动实验(LCCPE)以及大气扰动对照实验(GEFSPE).结果表明,在三组陆面扰动实验中,LSMPE能代表最大的不确定性且误差最小;ISMPE的离散度要比LCCPE稍大,但是... 相似文献
462.
利用ERA Interim再分析资料和2015—2019年中南地区航空器空中报告,对比分析7个指数在中南地区空中颠簸的适用效果,结果表明:①不同指数有无颠簸之间的值域重合率,Brown指数最低,其次是Ellrod1和Ellrod2,能够从指数值判断颠簸的强弱及存在与否,空报率较低;MOS CAT和L P指数值域重合率过高,容易造成较高的空报。②Ellrod1、Ellrod2和Brown计算的颠簸区与空中报告的位置对应最好,Dutton和HTG表现不稳定,MOS CAT和L P指数计算范围偏大,适用性较差。不同指数计算侧重点不同,当热力因素占主导时,HTG指数计算效果较好。 相似文献
463.
A mathematical model is developed for predicting the temperature distribution in an aquifer thermal energy storage (ATES) system, which consists of a confined aquifer bounded from above and below by the rocks of different geological properties. The main transfer processes of heat include the conduction and advection in the aquifer and the conduction in the rocks. The semi‐analytical solution in dimensionless form for the model is developed by Laplace transforms and its corresponding time‐domain solution is evaluated by the modified Crump method. Field geothermal property data are used to simulate the temperature distribution in an ATES system. The results show that the heat transfer in the aquifer is fast and has a vast effect on the vicinity of the wellbore. However, the aquifer temperature decreases with increasing radial and vertical distances. The temperature in the aquifer may be overestimated when ignoring the effect of thermal conductivity. The temperature distribution in an ATES system depends on the vertical thermal conduction in the rocks and the horizontal advection and thermal conduction in the aquifer. The present solution is useful in designing and simulating the heat injection facility in the ATES systems. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
464.
Investigation of highly efficient algorithms for solving linear equations in the discontinuous deformation analysis method
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Large‐scale engineering computing using the discontinuous deformation analysis (DDA) method is time‐consuming, which hinders the application of the DDA method. The simulation result of a typical numerical example indicates that the linear equation solver is a key factor that affects the efficiency of the DDA method. In this paper, highly efficient algorithms for solving linear equations are investigated, and two modifications of the DDA programme are presented. The first modification is a linear equation solver with high efficiency. The block Jacobi (BJ) iterative method and the block conjugate gradient with Jacobi pre‐processing (Jacobi‐PCG) iterative method are introduced, and the key operations are detailed, including the matrix‐vector product and the diagonal matrix inversion. Another modification consists of a parallel linear equation solver, which is separately constructed based on the multi‐thread and CPU‐GPU heterogeneous platforms with OpenMP and CUDA, respectively. The simulation results from several numerical examples using the modified DDA programme demonstrate that the Jacobi‐PCG is a better iterative method for large‐scale engineering computing and that adoptive parallel strategies can greatly enhance computational efficiency. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
465.
Tang Yuanjun Tan Dafang Mao Yi 《地球科学》1989,(3)
根据热流式量热计的Tian氏方程,用焦耳效应标定高温卡尔维微量热计。用偏差法得到的灵敏度值与积分法测得的值一致。用回归曲线对灵敏度实验值进行拟合,利用计算机求得灵敏度—温度回归曲线,得到了室温至700℃的全部灵敏度值,从而即可使用微量热计测量此温度范围内的未知样品热效应。 相似文献
466.
467.
The aim of this paper is to study the REE geochemistry of the Shenzhen Bay (SZB) and Dapeng Bay(DPB) modern sediments, discuss their REE distribution patterns, reveal the REE geochemical difference between the two bays which share the same material source but are deposited in different sedimentary environments, and expound their dynamic changes.It can be concluded that the SZB and DPB sediments are essentially of continental source.Their REE distribution patterns are quite different from those of Pacific pelagic sediments, but are very similar to those of South Chi-na granites.Because of different sedimentary environments prevailing in the SZB and DPB, some REE fractionation would have taken place in the sediments of the two bays. 相似文献
468.
基于栅格数据的流域降雨径流模型 总被引:30,自引:0,他引:30
本文在研究降雨时空分布不均匀与下垫面自然地理参数空间分布不均匀,对降雨径流过程影响的基础上,提出了一种在地理信息系统支持下的动态分布式降雨径流流域模型,实现了基于栅格的坡面产汇流与河道汇流的数值模拟,能够获得流域上任意模拟时刻任意栅格的径流量。模型视栅格为水文一致性单元,水文参数在栅格内一致,在相邻栅格间变化,采用Holtan模型计算下渗率,水量平衡方程和线性水库的马斯京根法进行栅格产汇流演算,模 相似文献
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470.