共查询到20条相似文献，搜索用时 31 毫秒
1.
Progress in Researches on Ensemble Forecasting of Extreme Weather Based on Numerical Models 总被引：1，自引：1，他引：0
Under the background of climate change, extreme weather events (e.g., heavy rainfall, heat wave, and cold damage) in China have been occurring more frequently with an increasing trend of induced meteorological disasters. Therefore, it is of great importance to carry out research on forecasting of extreme weather. This paper systematically reviewed the primary methodology of extreme weather forecast, current status in development of ensemble weather forecasting based on numerical models and their applications to forecast of extreme weather, as well as progress in approaches for correcting ensemble probabilistic forecast. Nowadays, the forecasting of extreme weather has been generally dominated by methodology using dynamical models. That is to say, the dynamical forecasting methods based on ensemble probabilistic forecast information have become prevailing in current operational extreme weather forecast worldwide. It can be clearly found that the current major directions of research and development in this field are the application of ensemble forecasts based on numerical models to forecasting of extreme weather, and its improvement through bias correction of ensemble probabilistic forecast. Based on a relatively comprehensive review in this paper, some suggestions with respect to development of extreme weather forecast in future were further given in terms of the issues of how to propose effective approaches on improving level of identification and forecasting of extreme events. 相似文献
2.
10～30d延伸期天气预报方法研究进展与展望 总被引：2，自引：0，他引：2
Yang Qiuming 《地球科学进展》2015,30(9):970-984
10~30 d延伸期预报是国际大气科学关注的研究热点。这一时间段的预报对开展防灾、救灾工作具有极其重要的价值和意义,该工作需要结合初始气象条件、海洋、大气以及气候的影响因素,其中观测资料具有复杂性、综合性、全球性等,这些科学大数据反映和表征着复杂的自然现象与关系,具有高度数据相关性和多重数据属性,预测过程十分复杂。分析了延伸期预报的各种主流方法,其中重点介绍了动力模式、经典统计和大数据方法 3类预报方法的研究现状,并探讨了各种方法的优势和不足,在此基础上对目前延伸期预报领域存在的问题进行了讨论和总结。对延伸期预报方法的未来发展方向和应用前景给以展望。 相似文献
3.
Atmospheric physics in numerical weather prediction model which predominantly determines the evolution of atmospheric processes is mainly described by physical parameterization. As a result, the development of physical parameterization has been a hot research issue in the area of numerical prediction for a long time. In this regard, the theoretical background and history of physical parameterization schemes for convection, microphysics, and planetary boundary layer, were reviewed in this study. It is suggested that the advance of physical parameterization for the model with high-resolution grid spaces should be considered as a principle issue for numerical model development in the future. Although the gird spaces in current operational numerical models generally decrease toward 10 km owing to the rapid development of high-performance computation, yet most of these schemes are designed for coarse grid spaces. Because of this kind of deficiency, the theoretical basis of these schemes inevitably faces controversy. Directions for development of physical parameterization were also suggested according to the trends of research in numerical prediction. 相似文献
4.
The soil hydrological process in land surface models and its influences on weather and climate simulation have got much attention by scholars both at home and abroad. First, this paper traced the definition and determination of soil moisture, and then reviewed its parameterization in different models, including soil-water characteristic curves for different soil types and numerical methods for solving soil moisture equations. Moreover, methods of soil hydrological parameter determination and uncertainties within land surface models were specified. Also, the importance of methods in parameter sensitivity analysis and optimization was emphasized, and the new datasets of soil hydraulic parameters would play a very important role in the improvement of the land surface model and soil moisture simulation. Finally, the research progress of feedback mechanism between soil moisture and precipitation was summarized. Spatial and temporal distribution of soil moisture and its abnormal would cause a positive feedback, and on the contrary, the meso-scale characteristics of soil moisture distribution had a negative feedback. By summarizing the progresses of the uncertainties and problems in soil moisture simulation, the influences of soil moisture on simulating weather and climate were pointed out. 相似文献
5.
随着全球气候变化、自然变迁及陆表生境改变,极端天气频发且呈现出多尺度时空变异特征,对其进行预报和预警一直是气象水文领域关注的焦点。临近预报可较准确地预报未来短时间天气显著变化,是当前预报强降水等极端事件的主要手段。从基于天气雷达0~3 h外推临近预报、融合数值模式0~6 h临近预报的发展历程梳理了临近预报的研究进展,阐述了雷达外推算法的发展进程、雷达外推预报与数值模式预报融合技术进展,指出"取长补短"的0~6 h融合预报在提高降水预报精度、延长降水预见期等多方面有较大的发展潜力,进一步探寻及提升融合技术是未来融合预报发展的核心。将临近预报以气象水文耦合的方式引入水文预报是从源头提高水文预报精度、保障水文预报效果的主要途径,总结了现阶段主流耦合方式、空间尺度匹配技术、水文模型不确定等陆气耦合中的关键问题,阐述了外推临近预报、融合临近预报作为水文预报输入的研究进展,明确了融合临近预报在延长洪水预见期、提高洪水预报精度中存在优势,并讨论了未来的研究重点及发展方向。 相似文献
6.
Mountain range specific analog weather forecast model is developed utilizing surface weather observations of reference stations
in each mountain range in northwest Himalaya (NW-Himalaya). The model searches past similar cases from historical dataset
of reference observatory in each mountain range based on current situation. The searched past similar cases of each mountain
range are used to draw weather forecast for that mountain range in operational weather forecasting mode, three days in advance.
The developed analog weather forecast model is tested with the independent dataset of more than 717 days (542 days for Pir
Panjal range in HP) of the past 4 winters (2003–2004 to 2006–2007). Independent test results are reasonably good and suggest
that there is some possibility of forecasting weather in operational weather forecasting mode employing analog method over
different mountain ranges in NW-Himalaya. Significant difference in overall accuracy of the model is found for prediction
of snow day and no-snow day over different mountain ranges, when weather is predicted under snow day and no-snow day weather
forecast categories respectively. In the same mountain range, significant difference is also found in overall accuracy of
the model for prediction of snow day and no-snow day for different areas. This can be attributed to their geographical position
and topographical differences. The analog weather forecast model performs better than persistence and climatological forecast
for day-1 predictions for all the mountain ranges except Karakoram range in NW-Himalaya. The developed analog weather forecast
model may help as a guidance tool for forecasting weather in operational weather forecasting mode in different mountain ranges
in NW-Himalaya. 相似文献
7.
Statistical bias correction methods for numerical weather prediction (NWP) forecasts of maximum and minimum temperatures over India in the medium-range time scale (up to 5 days) are proposed in this study. The objective of bias correction is to minimize the systematic error of the next forecast using bias from past errors. The need for bias corrections arises from the many sources of systematic errors in NWP modeling systems. NWP models have shortcomings in the physical parameterization of weather events and have the inability to handle sub-grid phenomena successfully. The statistical algorithms used for minimizing the bias of the next forecast are running-mean (RM) bias correction, best easy systematic estimator, simple linear regression and the nearest neighborhood (NN) weighted mean, as they are suitable for small samples. Bias correction is done for four global NWP model maximum and minimum temperature forecasts. The magnitude of the bias at a grid point depends upon geographical location and season. Validation of the bias correction methodology is carried out using daily observed and bias-corrected model maximum and minimum temperature forecast over India during July–September 2011. The bias-corrected NWP model forecast generally outperforms direct model output (DMO). The spatial distribution of mean absolute error and root-mean squared error for bias-corrected forecast over India indicate that both the RM and NN methods produce the best skill among other bias correction methods. The inter-comparison reveals that statistical bias correction methods improve the DMO forecast in terms of accuracy in forecast and have the potential for operational applications. 相似文献
8.
Leiming Ma 《地球科学进展》1986,35(6):551-560
Numerical weather prediction, which is the major basis of current weather forecast, has some shortcomings, such as the understanding of the law of atmospheric motion, the assimilation and application of observation data, the expression of model physics, etc., leading to the forecast error of weather. The rapid development of artificial intelligence technology in recent years provides a new possibility for the advancement and innovation of weather forecast. In this paper, the background of the development of artificial intelligence, the current situation of the application of artificial intelligence technology to weather forecast and the future development trend are mainly described to account for this possibility. After that, the idea for development of weather forecast technology based on the integration of artificial intelligence and numerical forecast is put forward. Particularly, this study stresses that, in order to advance the AI algorithm of weather forecast in the future, it is requested to focus on the nonlinear and chaotic characteristics of atmospheric motion leading to the uncertainty of forecast. Starting from the essence of mathematics and physics, we need to realize the hybrid modeling of mathematics and physics, not only to establish the framework of input-output mapping, but also to provide solutions to the bottleneck problems of weather forecast. 相似文献
9.
陇南地质灾害气象预报及预警技术研究 总被引：4，自引：1，他引：3
陇南地处甘肃东南边陲,东接秦岭．南通巴蜀,山高谷深、梁峁起伏、沟壑纵横,滑坡、泥石流地质灾害分布广泛,危害严重,是我国四大滑坡、泥石流集中高发区之一．给该区国民经济的发展和人民生命财产的安全带来了严重威胁。在这类地区开展地质灾害气象预报预警,是我国建设好生态环境,搞好防灾减灾气象服务工作的新课题。该文阐明了地质灾害气象预报预警的含义与内容,分析了降雨地段产生滑坡、泥石流的诱因,探索了在土石山区地质灾害气象预报预警的技术措施、方法和效益。 相似文献
10.
基于2 474个国家级气象台站1954-2015年观测的对流性天气现象（包括雷暴、闪电、冰雹、大风）数据,进行了有效的质量控制,并采用气候统计学方法,研究了中国对流性天气的时空变化特征和气候趋势。结果表明：全国平均的雷暴、闪电、冰雹、大风发生频率分别为11.0%、6.8%、0.33%和3.8%,且季节变化明显。我国雷暴、闪电日数自北向南基本呈逐渐增多的格局。在内蒙古地区、青藏高原、沿海地区等三个平均风速较大的地区,发生大风天气现象的日数也相应较多。对流性天气现象年发生日数呈下降趋势。分别有68.3%、67.5%、0.8%、41.6%台站雷暴、闪电、冰雹、大风日数年变化存在显著减少趋势。 相似文献
11.
依据甘肃兰州市1955-2010年沙尘暴、 浮尘天气事件年变化资料, 划分年强度分级, 应用Markov模型对其不同强度发生概率进行分析, 在此基础上预测和检验了2011年兰州沙尘暴浮尘天气事件的发生概率.结果显示: 2011年沙尘暴发生的特强年、 强烈年、 强发生年、 一般发生年和少发年的概率为,而事实上2011年发生沙尘暴0次,属于少发年, 符合预测结果; 2011年浮尘天气发生的特强年、 强烈年、 强发生年、 一般发生年和少发年的概率为,而事实上2011年发生浮尘9次,介于平常年和少发年范围, 符合预测结果.随着时间序列的延长, Markov模型可成为短期沙尘暴浮尘天气变化预测的有效途径. 相似文献
12.
David P. Bacon Nash’at N. Ahmad Thomas J. Dunn Michael C. Monteith Ananthakrishna Sarma 《Natural Hazards》2008,44(3):317-327
By definition, a crisis is a situation that requires assistance to be managed. Hence, response to a crisis involves the merging
of local and non-local emergency response personnel. In this situation, it is critical that each participant: (1) know the
roles and responsibilities of each of the other participants; (2) know the capabilities of each of the participants; and (3)
have a common basis for action. For many types of natural disasters, this entails having a common operational picture of the unfolding events, including detailed information on the weather, both current and forecasted, that may impact on either
the emergency itself or on response activities. The Consequences Assessment Tool Set (CATS) is a comprehensive package of
hazard prediction models and casualty and damage assessment tools that provides a linkage between a modeled or observed effect
and the attendant consequences for populations, infrastructure, and resources, and, hence, provides the common operational
picture for emergency response. The Operational Multiscale Environment model with Grid Adaptivity (OMEGA) is an atmospheric
simulation system that links the latest methods in computational fluid dynamics and high-resolution gridding technologies
with numerical weather prediction to provide specific weather analysis and forecast capability that can be merged into the
geographic information system framework of CATS. This paper documents the problem of emergency response as an end-to-end system
and presents the integrated CATS–OMEGA system as a prototype of such a system that has been used successfully in a number
of different situations. 相似文献
13.
在对流层内,闪电产生的氮氧化物(LNOx)是氮氧化物(NOx)的主要来源之一,这一区域内,由于NOx生命史较长,且控制着对流层臭氧(O3)和氢氧根(OH)的含量,影响着全球大气环境和气候变化.针对LNOx量的估算这一大气化学及雷电物理领域内的研究热点,介绍了NOx的主要来源、LNOx的产生机制及其对气候变化的重要性,详细综述了国内外现有的估算LNOx量的主要方法和估算结果.综述结果表明,目前估算LNOx量采用的研究方法主要有野外观测、实验室模拟、理论模式计算和卫星数据反演,主要通过观测或假设得到单位能量产生的NOx量,或单位通道长度产生的NOx量,同时通过观测或假设得到一次放电通道产生的总能量或一次放电的总通道长度,进而外推或数值模拟某一局地区域或全球的LNOx.由于不同地区、不同雷暴、甚至不同的闪电个体之间的显著差异导致不同的研究者估算LNOx时采用的参数值不同,进而使得LNOX估算量的结果差异较大,不确定性增大.近30年LNOx较为精确的产量计算结果平均值为5.2(2.8 ～9.1) Tg/a.最后提出,今后需继续对比分析利用先进的观测手段得到NOx和闪电的野外观测和卫星观测数据,进一步认识LNOx的产生机制,得到针对不同地区、不同强度的雷暴和不同的闪电个体估算NOx的参数取值,进一步减小估算LNOx时所用到的各个参数的不确定性.在此基础上,利用大气化学数值模式模拟局地或全球LNOx的产生和演变及其对其他空气成分的影响和作用,进一步认识LNOx在全球气候变化中的作用. 相似文献
14.
陕西省地质灾害-气象预报预警系统研制及应用 总被引：5，自引：0，他引：5
为了提高地质灾害-气象预报预警工作的自动化程度和产品的质量,文章从计算机系统制作的角度探讨了地质灾害-气象预报预警的方法,论述了陕西省地质灾害-气象预报预警系统的运行环境、软件功能、空间数据库、模型方法等内容,并介绍了陕西省汛期地质灾害-气象预报预警的应用实例。 相似文献
15.
我国雷电灾害及相关因素分析 总被引：14，自引：0，他引：14
为了更好地揭示雷电灾害的时空分布规律和成因机制过程,在1997—2006年全国雷电灾害数据库和星载闪电探测数据的基础上,分析研究了雷电灾害及相关因素的特征,包括雷电灾情、孕灾环境、致灾因子、承灾体及其相互作用,得到以下一些结果:①雷灾事故数、雷灾人员伤亡数与我国不同地区的致灾因子(闪电活动)、承灾体(人口和经济发展现况)成正相关;雷电灾情不同类型与承灾体类型(城乡人口比例、经济发展现况)有密切关系;②我国雷电灾情和闪电活动的时间特征是紧密相关的,同时雷电灾情的时间特征与人们的作息时间相关;③不同的孕灾环境下造成雷电伤害人员的方式特征不同,雷击死亡人数在农田最多,而受伤人数在建构筑物内最多;④80%的雷灾伤亡人员事故只涉及1~2人的生命安全,其中1人遭受雷击的占总事件的61%;⑤重大雷灾伤亡事件直接与承灾体的脆弱性有关。 相似文献
16.
贵州省汛期地质灾害气象预报预警的探索与实践 总被引：1，自引：0，他引：1
从气象因素和全省地质灾害隐患入手逐步深化研究降水和地质环境与地质灾害发生的关系,由浅入深,在尝试和探索中开展地质灾害的预报预警研究,提出了基于GIS的地质灾害气象预警方法.并通过对2004年的地质灾害实例验证预报和2005年4-7月预报预警取得了很好的效果.本文提出的气象预警方法合理可行、简便实用,特别适用于开展省级地质灾害气象预警业务中应用. 相似文献
17.
18.
大气波导是对流层中具有异常大气折射率梯度的大气层,对于评估和预测电磁波传播和海上探测通信系统等具有重要的科学意义和应用价值.以海上发生的大气波导类型为线索总结了与大气波导相关的研究方法.在蒸发波导研究中以相似理论为基础,开发蒸发波导诊断模型为重点,开展区域海域适应性研究;海上悬空波导和表面波导从早期的定性分析到目前精确定量研究过程中,中尺度数值模式逐渐成为极其重要的研究手段,不仅提高了特定天气过程中大气波导模拟预测精度,而且在此基础上开展区域大气波导环境研究,分析其出现规律、气候原因等.针对海上大气波导研究现状,借鉴气象上的手段和技术,开展海上水文气象调查和电波传播实验,结合中尺度数值模式和海气耦合模式,采用同化技术和集合预报等手段,提高海上低空大气波导量化精度. 相似文献
19.
云分析预报方法研究进展 总被引：2，自引：1，他引：1
云作为地球大气系统的重要组成部分,不仅影响着气候变化和天气系统的发展演变,还与航空活动密切相关,一直以来是空军和民航部门非常关注的气象要素之一。在云探测、资料同化和反演方法发展的基础上,从实际业务保障和数值模式发展需求出发,综述国内外云分析、预报方法和云分析预报系统开发的研究成果,分析各类方法的优势和不足,明确国内外研究的主要差距,并探讨国内未来研究的方向。云分析方法中,探空对云廓线识别较好,卫星可见光和红外资料在云顶信息反演方面优势明显,多普勒雷达能够获取对流层中层和底层的云信息,而毫米波雷达能够很好地反映云三维结构信息,发展潜力巨大。云预报方法中,传统的统计和诊断方法发展较为成熟,而考虑了大气温湿和云微物理状况的大气辐射传输模式正演模拟云顶亮温的方法是未来的发展趋势。加强云探测技术,综合利用云分析预报方法,借鉴国外先进云分析预报系统的设计理念,积极开发我国自主的云分析预报系统,推动天气预报、航空气象保障和数值预报模式的发展将会是我国云研究的重要方面。 相似文献
20.
This study presents the evaluation of 1 year of operational lightning forecasts provided for Europe, using the Weather Research and Forecasting model coupled with a cloud-top height-based lightning parameterization scheme. Three different convective parameterization schemes were employed for parameterizing sub-grid cloud-top heights and consequently driving the lightning scheme. Triggering of the lightning scheme was controlled by means of a model-resolved microphysics-based masking filter, while the formulation for deriving lightning flash rates was also modified, assuming a single “marine” equation instead of the original equations discriminating between continental and marine lightning. Gridded lightning observations were used for evaluating model performance on a dichotomous decision basis. Analysis showed that the lightning scheme is sensitive to the parameterization of convection. In particular, the Kain–Fritsch convective scheme was found to outperform the Grell–Devenyi and Grell–Freitas schemes, showing a statistically significant better performance with respect to lightning prediction. This was most evident during the warm season, while smaller differences among the schemes were recorded during the cold season. Further, for all examined convective schemes, it was found that the application of the masking filter is desirable for improving model performance in terms of lightning forecasting. Last, the reported results revealed that the refinement of the formulation of the lightning parameterization scheme, adhering to a “global” marine equation instead of distinguishing between land and sea lightning, may be necessary in order to obtain reliable lightning forecasts. 相似文献