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1.
气象数据回归分析中的若干问题及其对策   总被引:2,自引:1,他引:2       下载免费PDF全文
俞善贤  陈孝源 《气象学报》1988,46(3):327-332
本文对回归分析在气象应用中存在的若干问题进行了讨论,分析了有些失误的主要原因。采用诊断方法可以发现这些问题,然后分别采用不同的对策,初步使用这些对策后,实际预报正确性和稳定性都有明显的提高。  相似文献   

2.
中国区域气候变化的模拟和问题   总被引:20,自引:6,他引:14  
对中国区域气候变化的模拟和问题作了介绍和讨论。本文还论述了侧边界处理方案对模拟结果的影响。最后对当前区域气候模拟中存在的问题和解决途径进行了必要的讨论。  相似文献   

3.
环境趋势和医学气象研究中的若干前沿科学问题   总被引:3,自引:1,他引:2  
简要介绍了当前全球气候、环境变化趋势下,大气环境和气象医学研究中的若干前沿科学问题,包括环境毒理学、空气污染对人体健康的损害、城市小气候与人体健康、气象病、医学气象预报以及气候变化与人体健康等方面的研究进展。    相似文献   

4.
本文提出利用省时显式方案积分两个高分辨有限区数值预报模式。其结果表明,这一积分方案可以使模式的计算效率大大提高,而由时间积分方案的变化所造成的预报差异比模式空间离散化方案的不同所造成的预报差异要小。同时还讨论了将省时显式方案用于有限区模式的边界处理问题,提出了一个与蛙跃格式等价的边界处理方案。  相似文献   

5.
In practice, there are problems of data reliability and ability of the data to represent the phenomena being considered. Often, the presence of gaps will shorten the records and will render spurious results or misleading conclusions. The aim of this study is to compare various treatment methods to make up the missing records. Temporal and spatial characteristics are studied before any record is being treated. Reference will be made to rainfall records for the Klang River basin, Malaysia. Studies indicate that the most appropriate approach is the modified normal ratio method.  相似文献   

6.
Recently large quantities of data from many different field experiments have become available to facilitate the examination of various proposed models of atmospheric dispersion. However, these data sets are invariably corrupted by some form of random noise and, also, significant baseline drift is often recorded. Consequently, these problems require careful consideration and treatment before the data can be used in model testing. In many papers, the noise is simply treated by thresholding but this is unacceptable since many valid readings are discarded. This paper examines the performance of two different noise removal methods that are more soundly based, both physically and mathematically. The first is a Wiener filter with certain modifications, and the second is a maximum entropy inversion technique. A comparison of the results of applying these methods is presented, with the emphasis on the practical treatment of the numerical and computational problems that arise. The problem of baseline drift is treated initially by applying a number of subjective fits. Subsequently the noise removal methods are applied. In general, it is found that the maximum entropy method performs better than the Wiener filter for the data sets examined here.  相似文献   

7.
针对炼油厂延迟焦化装置排放的冷焦水,采用不同处理方法,并进行环境空气质量影响的预测。结果表明:近年新研制的冷焦水密闭脱臭处理方法是目前最佳的处理手段,可以基本解决焦化装置恶臭污染环境问题。  相似文献   

8.
从建设县级污水处理厂实际出发,论述了目前辽宁省污水处理厂在建设和运行过程中存在的筹资困难、工艺不当、运行不力、污水回用率低等问题,并针对县镇具体情况,提出了小型污水处理工程应选择的工艺及配套管网建设应注意的事宜及在中水回用方面的建议。  相似文献   

9.
全国碳市场将在电力行业启动交易,配额分配方法是其核心。通过试点经验对比分析,将对全国起到借鉴作用。研究结果表明,八试点共纳入电力企业202家,在覆盖范围、信息披露、分配方法、抵消机制等方面存在共性和差异,但普遍存在基准线法基础薄弱、间接排放处理不科学、热电联产供电和供热分摊困难等问题。建议在制定全国碳市场电力部门配额分配方案时应考虑循序渐进、协调推进、稳定性、科学与实用、激励和灵活、公开透明等基本原则。  相似文献   

10.
数值天气预报和气候预测的可预报性问题   总被引:29,自引:7,他引:29  
考察由初始状态误差和模式中参数误差所引起的预报结果的不确定性。提出了数值天气预报与气候预测中三类可预报性问题,即,最大可预报时间,最大预报误差,初值与参数的最大允许误差。然后将这三类问题化成了对应的非线性优化问题,给出了处理此类非线性优化问题的思路,并且有数值方法对Lorenz模型研究了这三类问题。  相似文献   

11.
数字化天气雷达定标中应注意的一些问题   总被引:8,自引:0,他引:8  
定标是天气雷达定量测量的基础,论述了目前我国数字化天气雷达定标中存在的问题并提出了解决方案。  相似文献   

12.
本文提出了基于KKT条件的稀疏编码算法.首先,将非凸非光滑的稀疏编码问题分解成两个凸非光滑问题;然后,巧妙地运用两个矩阵使两个凸非光滑问题转换成三个光滑凸优化问题,并通过KKT条件对三个问题进行求解,再通过凸优化理论证明三个问题在其对应规则下是非增的.最后,实验结果验证了算法的收敛性.  相似文献   

13.
There are three common types of predictability problems in weather and climate, which each involve different constrained nonlinear optimization problems: the lower bound of maximum predictable time, the upper bound of maximum prediction error, and the lower bound of maximum allowable initial error and parameter error. Highly efficient algorithms have been developed to solve the second optimization problem. And this optimization problem can be used in realistic models for weather and climate to study the upper bound of the maximum prediction error. Although a filtering strategy has been adopted to solve the other two problems, direct solutions are very time-consuming even for a very simple model, which therefore limits the applicability of these two predictability problems in realistic models. In this paper, a new strategy is designed to solve these problems, involving the use of the existing highly efficient algorithms for the second predictability problem in particular. Furthermore, a series of comparisons between the older filtering strategy and the new method are performed. It is demonstrated that the new strategy not only outputs the same results as the old one, but is also more computationally efficient. This would suggest that it is possible to study the predictability problems associated with these two nonlinear optimization problems in realistic forecast models of weather or climate.  相似文献   

14.
Results generalizing a cycle of works, connected with formulation and solution of inverse problems for one-dimensional model of unsteady water flow in rivers are presented. Various procedures allowing determining all basic characteristics of complicated riverbed using observations of unsteady water flow are considered. Data on restoration, convolution and use of the received characteristics in numerical schemes of the short-term stream flow forecasting for several reaches of artificial and real riverbeds with flood plains are analyzed. The main problems connected with development of methods of solution of the inverse problems for mathematical models of hydrological processes are formulated in general view.  相似文献   

15.
陕西省干旱遥感监测业务化及应注意的问题   总被引:3,自引:2,他引:1  
李星敏  王钊  刘安麟 《气象》2005,31(12):73-76
经过多年研究,许多省份已开展了干旱遥感的监测与服务,根据在陕西省开展干旱遥感监测业务化时使用的方法及各方法的适用性及服务效果,提出了在干旱遥感监测业务化过程中应注意的问题和解决方法.  相似文献   

16.
该文阐述了在CRAY/VAX分布式系统和异构网络平台上建立数值天气预报系统业务化运行环境过程中遇到的困难和解决的方法,并指出目前业务运行环境中仍存在的一些问题。  相似文献   

17.
Upscaling in Global Change Research   总被引:1,自引:0,他引:1  
This paper reviews the problems of upscaling that arise, in the context of global change research, in a wide variety of disciplines in the physical and social sciences. Upscaling is taken to mean the process of extrapolating from the site-specific scale at which observations are usually made or at which theoretical relationships apply, to the smallest scale that is resolved in global-scale models. Upscaling is pervasive in global change research; although in some cases it is done implicitly. A number of conceptually distinct, fundamental causes of upscaling problems are identified and are used to classify the upscaling problems that have been encountered in different disciplines. A variety of solutions to the upscaling problems have been developed in different disciplines, and these are compared here. Improper upscaling can dramatically after model simulation results in some cases. A consideration of scaling problems across diverse disciplines reveals a number of interesting conceptual similarities among disciplines whose practitioners might otherwise not communicate with each other. Upscaling raises a number of important questions concerning predictability and reliability in global change research, which are discussed here. There is a clear need for more research into the circumstances in which simple upscaling is not appropriate, and to develop or refine techniques for upscaling.  相似文献   

18.
GRAPES_SDM沙尘模式应用及存在的问题   总被引:4,自引:0,他引:4  
对中国气象局兰州干旱气象研究所业务化运行的沙尘模式———GRAPES_SDM的业务化过程、预报效果及其预报中发现的现象进行了总结。结果认为,该模式具有较准确的可预报性能,但是也存在一些需要进一步改善的问题。  相似文献   

19.
论当前大气动力模式中存在的若干问题   总被引:5,自引:0,他引:5       下载免费PDF全文
文章提出了当前大气动力模式中存在的若干问题,如垂直离散问题、提高分辨率的问题、极地流场的预报问题、间断问题、非线性混淆问题和高纬地区纬向差商的计算问题等。在分析讨论这些问题时,也提出了可能解决的方法和途径,比如:垂直离散静力方程,在等距情况下,用lnσ坐标比用σ坐标会使计算误差显著减小;非线性混淆在用球谐函数作基函数时是存在的,但如参加乘积运算的函数足够光滑,非线性混淆作用可以忽略。  相似文献   

20.
近年来,多智能体系统的协调控制在多机器人合作控制、交通车辆控制、无人飞机编队和网络的资源分配等领域有着广泛的应用,成为当前控制学科的一个热点问题.首先介绍了多智能体系统的研究背景、智能体的概念和相关的图论知识;然后从多智能体系统协调控制包含的几个问题入手,即群集问题、编队控制问题、一致性问题和网络优化问题等,对其国内外的发展现状进行了总结和分析;最后,给出了多智能体系统有待解决的一些问题,以促进对多智能体系统协调控制理论与应用的进一步研究.  相似文献   

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