共查询到20条相似文献，搜索用时 31 毫秒
1.
S. A. Myslenkov A. A. Shestakova P. A. Toropov 《Russian Meteorology and Hydrology》2016,41(10):706-713
The results ofnumerical simulation of storm waves near the northeastern coast ofthe Black Sea using different wind forcing (CFSR reanalysis, GFS forecast, and WRF reanalysis and forecast) are presented. The wave modeling is based on the SWAN spectral wave model and the high-resolution unstructured grid for the Tsemes Bay. The quality estimates of wave simulation results for various wind forcing are provided by comparing the model results with the instrumental data on wind waves in the Tsemes Bay. It is shown that the forecast of the maximum wave height for some storms using the WRF wind forcing is more accurate than that based on the GFS forcing. 相似文献
2.
寒潮暴风雪天气过程中数值预报产品的检验分析 总被引：2，自引：0，他引：2
采用1984－1994年3－5月的B模式物理量预告资料、ECMWF的500hPa高度场、地面气压场预告资料，逐个考察它们对寒潮暴风雪天气的预报能力，结果表明高度场、气压场、涡度、垂直速度、水汽通量、水汽通量散度、温度、全风速、温度露点差等预报量对阿勒泰区域性的寒潮暴风雪天气有较强的预报能力。 相似文献
3.
A high-precision digital elevation model of the Caspian Sea with the spatial resolution of 0.001° x 0.001° is constructed and used as a basis for computation grids of various scales. A three-level scheme for calculating wind waves with the sequence of nested grids (Caspian Sea-Northern Caspian, Absheron Peninsula, Turkmenbashy city-the Northern Caspian key areas) is developed. A scenario designer is implemented which considers in calculations the ice edge position and the coastline dynamics. The SWAN spectral wave model is adapted to the Caspian Sea conditions. The series of calculations and the comparison of the obtained results with observational data are provided. It is found that the best result is obtained when corrected reanalysis data are used for calculations. 相似文献
4.
使用集合天气预报系统的多个成员的风场预报来驱动海浪模式WAVEWATCH Ⅲ, 计算出含多个成员的海浪预报场,并相应开发出各海浪要素的集合预报产品,如集合平均、离散度、集合概率等,建立了一个集合海浪数值预报系统。使用该系统进行了2007年9—10月为期两个月的预报试验,利用太平洋和大西洋海域范围的浮标观测资料对系统的预报水平的初步检验分析显示,该集合海浪预报方法能够有效地将传统的确定性预报扩展到概率预报领域,且集合平均的预报水平要优于单一的确定性预报,采用集合预报方法可以提供单纯确定性预报所不能够提供的额外信息,具有较好的应用潜力。 相似文献
5.
Diana J. M. Greenslade Eric W. Schulz Jeff D. Kepert Graham R. Warren 《Journal of Atmospheric & Ocean Science》2005,10(3):261-287
Recent work has demonstrated that surface marine winds from the Bureau of Meteorology's operational Numerical Weather Prediction (NWP) systems are typically underestimated by 5 to 10%. This is likely to cause significant bias in modelled wave fields that are forced by these winds. A simple statistical adjustment of the wind components is shown to reduce the observed bias in Significant Wave Height considerably. The impact of increasing the vertical resolution of the NWP model and assimilating scatterometer data into the model is assessed by comparing the resulting forecast wind and waves to observations. It is found that, in general, the inclusion of scatterometer observations improves the accuracy of the surface wind forecasts. However, most of the improvement is shown to arise from the increased number of vertical levels in the atmospheric model, rather than directly from the use of the observations. When the wave model is forced with surface winds from the NWP model that includes scatterometer data, it is found that the scatterometer assimilation does not reduce the systematic bias in surface wave forecasts, but that the random errors are reduced. 相似文献
6.
J. C. Hargreaves D. J. T. Carter P. D. Cotton J. Wolf 《Journal of Atmospheric & Ocean Science》2002,8(1):41-66
This paper describes the development and application of a technique for using satellite altimeter measurements as boundary data to drive the nearshore spectral wave model, SWAN. The aim was to assess the impact in coastal areas of extreme events or changes in offshore climatology and to extend the usefulness of satellite altimetry further inshore.
For the purpose of verifying the technique, three test areas where both bathymetry and some in situ data were available were chosen. The technique could, potentially, be applied to any coastal location where there is bathymetric information although, as the results reported in this paper show, intelligence must be used in adapting the methodology for different sites. It is also necessary to have information on the local wind field from either models or measurements.
The experiments at the three test areas demonstrated that there is not a simple relationship between the offshore wave height climate and the inshore climate in a particular region. Important complicating factors are bathymetry, tidal range and incident wave angle. As was most clearly demonstrated in the Carmarthen Bay test area, bathymetric complexity leads to high spatial variation in the amount of wave energy dissipated close to the coast. In the study of extreme wave events described in this paper the exact value of the local wind field was not found to be critical.
This work was a first trial combining wave climatology derived from satellite altimetry with a third generation coastal wave model so was necessarily experimental. The general trends and patterns of spatial variation obtained are encouraging but there remains significant, unquantifiable uncertainty in the results. Better observations of nearshore waves, improved understanding of the joint probability distribution of water level and waves as well as more knowledge of future climate change would all improve accuracy. 相似文献
For the purpose of verifying the technique, three test areas where both bathymetry and some in situ data were available were chosen. The technique could, potentially, be applied to any coastal location where there is bathymetric information although, as the results reported in this paper show, intelligence must be used in adapting the methodology for different sites. It is also necessary to have information on the local wind field from either models or measurements.
The experiments at the three test areas demonstrated that there is not a simple relationship between the offshore wave height climate and the inshore climate in a particular region. Important complicating factors are bathymetry, tidal range and incident wave angle. As was most clearly demonstrated in the Carmarthen Bay test area, bathymetric complexity leads to high spatial variation in the amount of wave energy dissipated close to the coast. In the study of extreme wave events described in this paper the exact value of the local wind field was not found to be critical.
This work was a first trial combining wave climatology derived from satellite altimetry with a third generation coastal wave model so was necessarily experimental. The general trends and patterns of spatial variation obtained are encouraging but there remains significant, unquantifiable uncertainty in the results. Better observations of nearshore waves, improved understanding of the joint probability distribution of water level and waves as well as more knowledge of future climate change would all improve accuracy. 相似文献
7.
《大气和海洋科学快报》2023,16(4):100347
Accurate forecasting of ocean waves is of great importance to the safety of marine transportation. Despite wave forecasts having been improved, the current level of prediction skill is still far from satisfactory. Here, the authors propose a new physically informed deep learning model, named Double-stage ConvLSTM (D-ConvLSTM), to improve wave forecasts in the Atlantic Ocean. The waves in the next three consecutive days are predicted by feeding the deep learning model with the observed wave conditions in the preceding two days and the simultaneous ECMWF Reanalysis v5 (ERA5) wind forcing during the forecast period. The prediction skill of the d-ConvLSTM model was compared with that of two other forecasting methods—namely, the wave persistence forecast and the original ConvLSTM model. The results showed an increasing prediction error with the forecast lead time when the forecasts were evaluated using ERA5 reanalysis data. The d-ConvLSTM model outperformed the other two models in terms of wave prediction accuracy, with a root-mean-square error of lower than 0.4 m and an anomaly correlation coefficient skill of ∼0.80 at lead times of up to three days. In addition, a similar prediction was generated when the wind forcing was replaced by the IFS forecasted wind, suggesting that the d-ConvLSTM model is comparable to the Wave Model of European Centre for Medium-Range Weather Forecasts (ECMWF-WAM), but more economical and time-saving.摘要海浪预报对海上运输安全至关重要. 本研究提出了一种涵盖物理信息的深度学习模型Double-stage ConvLSTM (D-ConvLSTM) 以改进大西洋的海浪预报. 将D-ConvLSTM模型与海浪持续性预测和原始ConvLSTM模型的预测技巧进行对比. 结果表明, 预测误差随着预测时长的增加而增加. D-ConvLSTM模型在预测准确度方面优于前二者, 且第三天预测的均方根误差低于0.4 m, 距平相关系数约在0.8. 此外, 当使用IFS预测风替代再分析风时, 能够产生相似的预测效果. 这表明D-ConvLSTM模型的预测能力能够与ECMWF-WAM模式相当, 且更节省计算资源和时间. 相似文献
8.
三种全球预报产品中国区近地面气温短期预报效果检验 总被引：1，自引：0，他引：1
全球气象预报产品是扩散模式、空气质量模式的重要基础资料和前提条件,其误差直接影响模拟结果的准确度。为考察不同气象预报产品的误差,选取2016年6月至2017年5月GFS、ECMWF、T639三种全球气象预报产品,利用中国2100个地面观测站数据,对预报产品中近地面气温进行了对比,并分析了其在不同季节、不同区域的特征。结果表明：在中国区域三种气象产品气温预报存在偏低预报的趋势,其均方根误差的年平均值为2.60—3.52℃,相关系数的年平均值为0.89—0.92,平均绝对误差的年平均值为1.87—2.67℃。整体而言,EC表现最佳,其余依次为GFS、T639。气温预报误差存在季节变化特征,三种产品均方根误差与平均绝对误差均表现为夏秋季优于春冬季,相关系数表现为秋冬季优于春夏季。气温预报误差存在明显的地域差异,三种气象预报产品的气温误差空间分布特征较为相似,在中国华东地区误差值表现较低,在西南地区误差较高。同时,其误差水平在中国沿海地区表现较低,在地形复杂地区表现较高。 相似文献
9.
大气重力波是一种普遍存在于大气层中的波动现象,与多种不同尺度天气现象均有密切联系,研究平流层重力波的时空分布特征及其可能影响机制对于全球大气环流、大尺度气候变化和各类中尺度天气系统的研究具有重要意义.利用基于PANGAEA数据中心提供的2002—2015年逐月平流层重力波参数资料和SPARC数据中心提供的1992—1997年逐月纬向风资料,分析了平流层重力波参数的时空分布特征,并讨论了影响平流层重力波变化的可能机制.结果表明,对于重力波参数的纬向平均分布,平流层重力波扰动温度和垂直波长随高度增加而增大,而水平波数和绝对动量通量则相反.在夏半球的中低纬度和冬半球的高纬度存在重力波参数的大值区,在赤道附近全年存在重力波参数的低值区.平流层重力波参数水平分布表现为纬向上的带状分布,强度随季节发生变化.在相同纬度,重力波参数的大值中心出现在大陆,特别是山脉地区.平流层纬向风和重力波参数二者的分布具有一致性,说明背景风对大气的扰动是影响重力波参数的可能机制之一. 相似文献
10.
应用国家气象中心模式检验方法对GRAPES_Meso V3.0模式2008年2月-2009年3月的试验预报产品,如降水、中低层高度、温度和风场预报进行统计检验。检验结果表明:V3.0模式降水预报性能得到明显改善,年及四季平均的各级降水TS评分显著提高,除了秋、冬季的48h中雨和暴雨预报外,TS评分明显高于V2.5模式,但V3.0模式的预报偏差偏大,中雨以上偏大更明显。从预报的季节平均降水率分布来看,对秋、冬季我国东部24h降水预报偏小改进明显,对春、夏季强降水中心位置及强度预报也好于V2.5模式,但是48h降水预报明显偏大,逐日降水率演变图也印证了这一点。此外,V3.0模式对500hPa高度和风场及48h预报的850hPa风场和温度场改进显著,对于850hPa高度和温度的24h预报,除夏季外,其他季节预报效果优于业务模式。 相似文献
11.
The Weather Research and Forecasting (WRF) model was compared with daily surface observations to verify the accuracy of the WRF model in forecasting surface temperature, pressure, precipitation, wind speed, and direction. Daily forecasts for the following two days were produced at nine locations across southern Alberta, Canada. Model output was verified using station observations to determine the differences in forecast accuracy for each season.Although there were seasonal differences in the WRF model, the summer season forecasts generally had the greatest accuracy, determined by the lowest root mean square errors, whereas the winter season forecasts were the least accurate. The WRF model generally produced skillful forecasts throughout the year although with a smaller diurnal temperature range than observed. The WRF model forecast the prevailing wind direction more accurately than other directions, but it tended to slightly overestimate precipitation amounts. A sensitivity analysis consisting of three microphysics schemes showed relatively minor differences between simulated precipitation as well as 2?m surface temperatures. 相似文献
12.
利用美国西海岸7个近岸浮标2012年全年和中国近岸8个气象浮标2012年1—6月的风场观测数据,检验了卫星散射计ASCAT近岸风场产品中的风速和风向在近岸海域的精度。检验结果表明:在美国西海岸近岸海域,ASCAT近岸风场产品中的风速与浮标的风速一致性高,但ASCAT近岸风场产品中风向的精度受离岸距离、风速和风向等因素的影响,在离岸近的海域ASCAT近岸风场产品与浮标观测风场的一致性较差。统计发现,将低风速 (不超过3 m·s-1) 剔除可明显提高ASCAT近岸风场产品在近岸海域的精度。另外,ASCAT近岸风场产品的风向精度在不同风向上存在差异,表现为从陆地吹向海洋风向精度较小,而从海洋吹向陆地风向精度较高。在中国近岸海域,受地形影响,渤海海域ASCAT近岸风场产品与气象浮标观测的风向差异大,在其他近岸海域的ASCAT近岸风场产品和气象浮标的观测风场的对比结果与美国西海岸风场的对比结果特征相似。 相似文献
13.
The results of computation of wind wave fields for two versions of the WAM model (the original version of the European wind wave model WAM4 and its modified version WAM4-M) are compared with satellite measurements. The mapped data on the daily averaged wave height obtained from the data of combined measurements of several satellite altimeters are used. Significant correlation between wind wave series for both models and satellite data is demonstrated as well as the advantage of the WAM4-M model over its original version in accuracy and some statistical parameters of comparison with the altimeter. Advantages and shortcomings of numerical and remote sensing methods of wind wave investigation at the ocean scales are noted. 相似文献
14.
基于ECMWF模式的集合预报数据,利用联合概率方法,针对北京地区冬季影响最大的寒潮和夏季强对流两类灾害性天气,建立了适用于本地区的两种集合预报业务产品。选取2 m温度和10 m平均风速制作寒潮预警信号联合概率预报产品,选取对流有效位能和0-6 km垂直风切变制作强对流潜势联合概率预报产品。通过对北京地区近年寒潮和强对流天气的预报检验表明：寒潮预警信号联合概率方法,当预报概率达到10%及以上时,实况就有可能达寒潮蓝色预警信号的级别;此方法对北京西北部的预报性能较好,其次为北京的东南部地区;对达到蓝色预警信号标准的区域具有较高的预报命中率,但对达黄色预警信号级别的区域,漏报率较高。强对流潜势联合概率方法的空报率较高,当预报概率达90%-100%时,实况才有可能出现强对流;与局地强对流相比,全市性强对流天气的高概率预报区域较为集中。 相似文献
15.
基于TIGGE资料中欧洲中期天气预报中心(ECMWF)、美国国家环境预报中心(NCEP)和中国气象局(CMA)3个集合预报系统的地面气温集合预报资料,运用跳跃指数研究了3个集合预报系统中东亚地面气温的控制预报及集合平均预报的不一致性。结果表明,各个集合预报系统地面气温预报的时间平均不一致性指数差异较大。ECM WF时间不一致性指数最小,NCEP次之,CM A最大。另外NCEP的控制预报、ECM WF的控制预报和集合平均预报,这三者的时间平均不一致性指数随预报时效延长而增加,且集合平均预报一致性优于控制预报。而对于CMA预报的不一致性,无论是控制预报还是集合平均预报总体上都稳定地保持在较高的水平。此外,ECMWF的地面气温冬(夏)季预报的不一致性相对较强(弱),且单点跳跃随预报时效延长变化不明显,而控制预报和集合平均预报的异号两点跳跃以及三点跳跃出现的频率总体上随预报时效延长略有增加。 相似文献
16.
利用高分辨率的再分析资料ERA40，分析了纬向平均状态下北半球不同尺度的定常波对西风动量沿经向输送的气候态及其年变化。结果表明，对流层中定常波对西风动量输送最强的区域位于中纬度对流层的中上层，定常波在该区域长年向北输送纬向动量，且输送中心随季节有南北移动和强弱变化。此外，在高纬度地区的对流层中上层以及赤道对流层顶附近还有两个相对较弱的输送中心。前者对西风动量的输送长年向南，其垂直范围从对流层低层一直伸展到平流层下层，中心位置相对固定，强度有明显的季节变化。后者位置也相对固定，但输送方向随季节改变。平流层中定常波对西风动量的输送主要位于中高纬度的平流层中上层，定常波在该区域长年向北输送西风动量，中心位置非常稳定，而强度则随季节变化明显。行星尺度定常波的输送作用与总波动的输送作用非常一致，并在很大程度上决定了波动对动量输送强度的季节变化。天气尺度定常波和10波以上的短波的输送作用主要集中在中纬度对流层的中高层。前者与行星尺度定常波共同决定了该区域内的输送强度，并主导了输送中心的南北移动；后者的作用很小，除夏季外均可以忽略。作者给出的不同尺度定常波对西风动量输送的气候态分布不但可以作为日后研究其年际变化的基础，而且还可以为大气环流模式对大气环流模拟能力的评估提供重要的参考。 相似文献
17.
北冰洋地区海浪的生成和发展会受到海冰范围变化的显著影响。本文介绍了近年来基于浮标、潜标和走航观测,以及卫星遥感和数值模拟等方法开展的不同海冰覆盖度下北冰洋海浪的研究进展,包括海冰覆盖区海浪的传播机制等。北冰洋夏季开阔海域的平均有效波高可达3 m,在风暴期间,波弗特海有效波高可达5 m。除大西洋一侧,夏季北冰洋大部分海域海浪活动在过去几十年呈增强趋势,其中楚科奇-波弗特海有效波高增长趋势为1~3 cm/a。这一趋势主要是由海冰范围减少导致的风区增大和风暴的频率、强度增加共同导致的。基于CMIP5多模式集的预估结果显示,相比历史时期(1979—2005年),21世纪末(2081—2100年)北冰洋有效波高将以3 cm/a的速率持续增长,其中北冰洋中心地区东部海域增长最为明显。海浪活动增多会在消融期通过海浪-海冰正反馈机制促进海冰的消融。在沿岸地区,增多的海浪会加速海岸带侵蚀,促进沿岸冻土的崩解。极端海浪事件还会威胁航运安全。未来研究需基于更多的现场观测,加深对海冰范围和厚度变化影响下海浪的生成、发展、传播、衰减机制的认识,进一步提高冰区海浪模拟和预估水平。 相似文献
18.
H. Jean Thiébaux 《大气与海洋》2013,51(4):261-285
Abstract Analysis error patterns have been established for the Pacific Weather Centre Experiment Area, and comparisons made between errors computed for meteorological observing arrays, including Ocean Weather Ship (OWS) P, and errors computed for several alternative arrays which excluded OWS P. These assessments of the impact of replacing the ocean weather ship with alternative observing equipment indicate that, above the 1000‐mb pressure surface, there will be a significant loss of accuracy in the forecast‐minus‐observation analyses regardless of proposed additional report systems. Near the surface, forecast error variances are estimated to decrease slightly with an increase of reports from buoys and ships of opportunity within the region. The dependence of the assessments on the data selection procedure and on correlation representations for the region suggest that some loss may be compensated by more efficient use of available data. Refinements in the objective analysis scheme are seen to be especially important to analysis accuracy in regions lacking radiosonde coverage. 相似文献
19.
利用浮标资料,对“利奇马”影响期间浙江沿海风和海浪特征及其关系进行分析,并对欧洲中心模式预报与实况进行对比,基于模式预报分析海浪的空间结构。结果发现:(1)随着台风靠近、登陆和远离,海浪波型经历了混合浪—风浪—混合浪的变化,且最大波高越大周期越长,浙江南部沿海海浪较北部沿海更具风浪特点;(2)浪高受风速影响大,北部沿海更为明显,持续风向对浪高增大有明显作用,当风向由向岸转为与海岸线平行、或由与海岸线平行转为离岸时,浪高迅速减小,反之浪高迅速增大;(3)台风靠近和影响浙江时,有效波高与风速的等值线平行,7、8、10级风分别与巨浪、狂浪、狂涛区有很好的对应,有效波高越高,风速对波高的决定作用越明显。 相似文献
20.
Wind is the dominant process for wave generation. Detailed evaluation of metocean conditions strengthens our understanding of issues concerning potential offshore applications. However, the scarcity of buoys and high cost of monitoring systems pose a barrier to properly defining offshore conditions. Through use of numerical wave models, metocean conditions can be hindcasted and forecasted providing reliable characterisations.This study reports the sensitivity of wind inputs on a numerical wave model for the Scottish region. Two re-analysis wind datasets with different spatio-temporal characteristics are used, the ERA-Interim Re-Analysis and the CFSR-NCEP Re-Analysis dataset. Different wind products alter results, affecting the accuracy obtained. The scope of this study is to assess different available wind databases and provide information concerning the most appropriate wind dataset for the specific region, based on temporal, spatial and geographic terms for wave modelling and offshore applications. Both wind input datasets delivered results from the numerical wave model with good correlation. Wave results by the 1-h dataset have higher peaks and lower biases, in expense of a high scatter index. On the other hand, the 6-h dataset has lower scatter but higher biases. The study shows how wind dataset affects the numerical wave modelling performance, and that depending on location and study needs, different wind inputs should be considered. 相似文献