基于MM5模式的我国近海海洋风能资源评估

通过908专项调查资料和中尺度气象模式MM5(the Fifth generation Mesoscale Model)相融合的方法为我国近海风能资源评估提供一定时空分辨率的风场。本文主要探讨了将GTS常规观测资料、908专项调查资料和卫星遥感风场反演资料计入中尺度气象模式MM5的同化方法,同化美国NCEP水平分辨率为1°×1°的2007年-2008年再分析数据,重构了分辨率为0.1°×0.1°风场,对我国近海进行了两个模拟试验,并将不同模拟结果与实测值进行比较。结果表明,时空分辨率较高的观测资料同化风场模拟结果具有一定的改善作用。根据模拟结果计算了我国近海10m高度处平均风速、平均风功率密度和总蕴藏量等风能资源评估参数。计算结果表明:我国近海海洋风能资源总蕴藏量约为8.83×108kW,其中江苏、福建、广东和山东海洋风能资源丰富,辽宁和浙江海洋风能较为丰富。     

WRF三维变分同化在石羊河流域降水模拟中的应用

为探究石羊河流域降水特性对流域生态环境治理、水资源高效管理及利用的影响,采用NCEP ADP地面观测数据集,基于WRF3.9模式及其三维变分同化系统对石羊河流域两场降水过程进行不同嵌套区域的单次资料同化试验,并以研究区内65个站点逐日降水实测数据进行验证。结果表明,同化NCEP ADP资料对短时降水预报有明显改善作用,可提高降水模拟精度,但同化不同的嵌套区域对降水模拟结果有很大影响,其中同化第3层嵌套区域对降水的模拟效果最好;在此基础上对两场降水进行循环同化试验,其结果优于单次同化,24h累积降水空间分布更接近实况。     

从天气尺度到风力机尺度大气运动的动力模拟

建立起中尺度天气模式WRF(weather research and forecasting)和计算流体力学模式Fluent的耦合系统,将WRF输出当做边界条件驱动Fluent,用于风场信息的精确模拟。利用该系统对下垫面条件复杂的鄱阳湖区域风场进行模拟分析,并将模拟数据与两个测风数据集进行定量比较,结果表明WRF耦合Fluent系统模拟的近地风场信息比WRF直接模拟结果有明显改善,证实中尺度天气模式耦合计算流体力学模式的技术思路有很好的可行性。这个耦合系统实现了从天气尺度到风力机尺度大气运动的模拟,能相对准确地给出风电场区域小尺度地形变化引起的风场细节。     

不同初始场对WRF模式风场模拟效果的影响分析

利用不同初始场资料驱动WRF模式,对香港地区夏季一个月风场进行高分辨率数值模拟试验,选用15个地面自动气象站测风数据及1个探空站垂直风廓线实测资料与模拟结果进行比较分析。结果表明,3种初始场方案均能较好模拟风场变化及分布特点,不同初始场资料会在一定程度上影响风场模拟结果;JRA-55方案高估风速现象较为明显,风向日变化模拟误差相对较大;NCEP FNL与ERA-Interim方案模拟近地面风场精度相当,且优于JRA-55方案。3种方案模拟的垂直风廓线均存在近地层风速增幅过快、最大风速出现高度与实际不符等问题,此外,NCEP FNL与ERA-Interim方案能够准确反映近地层风向廓线的变化趋势,而JRA-55方案模拟效果与实际相差较大。     

近海区域风速数值模拟试验分析

在可持续能源发展战略的实施中，风能等可再生能源的开发利用是重要的战略选择。其中风能资源的评估是其开发利用的关键，如何利用有限的观测资料进行资源评估和分析就成为迫切需要解决的问题。该文利用中尺度气象模式MM5对海上风场进行模拟分析，模拟结果在风的分布趋势很好与多年平均实况吻合，为我国海上风资源的开发利用提供有力的科学依据。     

三种地形数据下WRF模式风场模拟对比试验研究

为提高近地面风场模拟精度,将SRTM3和ASTER高精度地形数据引入WRF中尺度模式中,并结合模式原有地形数据GTOPO30,对香港地区2013年11月风场进行模拟,同时选取模拟区域内29个地面气象监测站实测数据对不同地形数据下的10m高处风速模拟结果进行检验。结果表明,WRF模式能够较好地模拟近地面风场的日变化趋势,尤其在海拔较高的区域,模拟结果与实际情况非常吻合;相比于GTOPO30,SRTM3和ASTER数据能够更加准确描述研究区域的地形特征,两者对原地形高程的修正幅度均比较有限,用于近地面风速模拟时均能小幅改善模拟效果。     

3种再分析资料在太阳能资源评估中的适用性

基于1979—2019年中国53站逐月水平面总辐射（GHI）观测资料,采用REOF方法将中国GHI划分为北方地区、西南地区、长江中下游地区和东南地区4个区域,从太阳能资源的角度,对比NCEP/DOE、JRA55和ERA5大气再分析GHI资料与地面观测资料差异。结果表明：3种大气再分析GHI资料整体较地面观测偏大,均方根偏差和相对偏差最大的区域均位于30°N附近,年际变化一致性均为东南部优于西北部;ERA5数据在均方根偏差、相对偏差、年际变化规律以及空间分辨率等方面均优于NCEP/DOE和JRA55;1979—2019年期间,3种大气再分析资料与地面观测数据的差异呈减小趋势,其中JRA55和ERA5资料在各区域与观测之间的偏差减小趋势显著;太阳能资源稳定度方面,3种大气再分析资料在北方地区与观测接近,南方地区JRA55以偏高为主,NCEP/DOE和ERA5以偏低为主。     

基于WRF模式的光伏电站选址研究

目前国家太阳能辐射观测气象站较少,光伏选址的区域周边缺少辐射观测资料,部分区域甚至缺乏日照观测资料,在进行光伏电站前期评估时,缺乏进行太阳辐射量的推算、光伏系统的设计、系统配置及发电量计算的依据。采用中尺度数值预报WRF模式进行光伏电站场址区域太阳能总辐射数值模拟试验,输出的逐时辐射和温度资料为光伏电站选址提供了有利的支撑,对光伏发电工程的前期评价有较好的参考价值。     

实际地形风场CFD模拟中粗糙度的影响分析

以苏格兰Askervein小山为例,基于Fluent流体计算平台,结合NURBS地形建模方法,模拟了实际地形下的风场分布.分别在粗糙度长度为0～0.05m的情况下进行CFD风场模拟试验.与实测的风速加速比进行比较,发现模拟所得的风速加速比均方根误差在迎风面保持在6%以内,而背风面最大为26.56%,表明粗糙度条件对CFD风场模拟结果有较大影响.实现了用于CFD风场模拟的下垫面粗糙度精细化方法.在迎风坡和背风坡设置不同粗糙度长度的情况下,风速加速比均方根误差减小为7.42%,模拟结果在背风坡区域有明显改善.最后指出,在进行复杂地形风场CFD数值模拟时,有必要进行粗糙度条件的精细化设置.     

基于NWP/CFD嵌套的复杂地形风场模拟研究

为解决复杂地形边界层风场模拟的边界条件问题,结合中尺度数值天气预报(NWP)和小尺度计算流体动力学(CFD)技术,提出一种基于NWP/CFD嵌套的降尺度风场模拟方法。该方法依据NWP低分辨率输出结果,建立目标区域来流边界数据库,并结合反距加权插值获得CFD边界精细格点信息。以沿海地区2处复杂地形为对象,重现目标区域内的风场日变化。参考经验风剖面分布形式,验证插值算法在中小尺度耦合界面数据传递的适用性。然后基于模拟域内实测点数据及误差统计指标,评估风场模拟效果。结果表明,所提降尺度风场模拟方法能有效反映微地形、微气象对风力机尺度大气运动影响。     

Offshore wind resource assessment with WAsP and MM5: comparative study for the German Bight

In this study, two different approaches to estimate the wind resource over the German Bight in the North Sea are compared: the mesoscale meteorological model MM5 and the wind resource assessment program WAsP. The dynamics of the atmosphere of the year 2004 was simulated with the MM5 model, with input from the NCEP global model, without directly utilizing measurement data. WAsP estimations were calculated on the basis of six measurement stations: three on islands, two offshore and one onshore. The annual mean wind speed at onshore, offshore and island sites is estimated by both models. The predictions are compared both with each other and with measured data. A spatial comparison of the wind resource calculated by the two models is made by means of a geographical information system. The results show that the accuracy of the WAsP predictions depends mainly on the measurement station used as input. Small differences are shown in the estimations performed by the three island stations, despite the large geographical distance between them. Compared with the measurements of the offshore sites, they seem to be suitable for estimating the offshore wind resource from measurements on land. The two offshore stations show differences when predicting each other's mean wind speed with the WAsP method, while the MM5 calculations show a similar deviation for both sites. The largest differences between the two models are found at distances of 5–50km from the coast. While in WAsP the increase occurs in the first 10km from the coast, MM5 models an increase due to coastal effects for at least 50km. Copyright © 2006 John Wiley &Sons, Ltd.     

WRF模式在江苏省沿海风能预报系统中的应用

为研究WRF模式在沿海风能预报系统中的应用能力,以江苏省大丰市某70m高测风塔的2006年观测记录为例,基于4种不同近地面层-边界层参数化方案的组合,运用WRF模式分别模拟了该塔1、4、7、10月的逐小时风速,评估了不同近地面层-边界层参数化方案组合对沿海风电场轮毂高度风速的模拟效果,分析了WRF模式模拟沿海风电场风速的误差特征。结果表明,不同近地面-边界层参数化方案组合的总体模拟效果不同,MM5similarity近地面层和YSU边界层参数化方案组合的方案A效果稍好;4种参数化方案组合对秋、冬季节的风电场风速模拟精度都要明显好于春、夏季节,存在明显的季节性;WRF模式对海向风的模拟好于陆向风,且其模拟误差存在明显的方向性,沿海地区特殊的地形分布对其有显著的影响。     

Offshore wind speed estimates from a high‐resolution rapidly updating numerical weather prediction model forecast dataset

In association with the Department of Energy–funded Position of Offshore Wind Energy Resources (POWER) project, we present results from compositing a 3‐year dataset of 80‐m (above ground level) wind forecasts from the 3‐km High‐Resolution Rapid Refresh (HRRR) model over offshore regions for the contiguous United States. The HRRR numerical weather prediction system runs once an hour and features hourly data assimilation, providing a key advantage over previous model‐based offshore wind datasets. On the basis of 1‐hour forecasts from the HRRR model, we highlight the different climatological regimes of the nearshore environment, characterizing the mean 80‐m wind speed as well as the frequency of exceeding 4, 12, and 25 m s^?1 for east and west coast, Gulf of Mexico, and Great Lake locations. Preliminary verification against buoy measurements demonstrates good agreement with observations. This dataset can inform the placement of targeted measurement systems in support of improving resource assessments and wind forecasts to advance offshore wind energy goals both in New England and other coastal regions of the United States.     

Data assimilation impact of in situ and remote sensing meteorological observations on wind power forecasts during the first Wind Forecast Improvement Project (WFIP)

During the first Wind Forecast Improvement Project (WFIP), new meteorological observations were collected from a large suite of instruments, including wind velocities measured on networks of tall towers provided by wind industry partners, wind speeds measured by cup anemometers mounted on the nacelles of wind turbines, and wind profiles by networks of Doppler sodars and radar wind profilers. Previous data denial studies found a significant improvement of up to 6% root mean squared error (RMSE) reduction for short‐term wind power forecasts due to the assimilation of all of these observations into the National Oceanic and Atmospheric Administration (NOAA) Rapid Refresh (RAP) forecast model using a 3D variational data assimilation scheme. As a follow‐on study, we now investigate the impacts of assimilating into the RAP model either the additional remote sensing observations (sodars and radar wind profilers) alone or assimilating the industry‐provided in situ observations (tall towers and nacelle anemometers) alone, in addition to routinely available standard meteorological data sets. The more numerous tall tower/nacelle observations provide a relatively large improvement through the first 3 to 4 hours of the forecasts, which diminishes to a negligible impact by forecast hour 6. In comparison, the sparser vertical profiling sodars/radars provide an initially smaller impact that decays at a much slower rate, with a positive impact present through the first 12 hours of the forecast. Large positive assimilation impacts for both sets of instruments are found during daytime hours, while small or even negative impacts are found during nighttime hours.     

Eight years of wind measurements from scatterometer for wind resource mapping in the Mediterranean Sea

Eight years of wind observations from the SeaWinds scatterometer instrument on the National Aeronautics and Space Administration QuikScat satellite and in situ data from 11 locations in the Mediterranean have been considered. The data have been co‐located in time and space, and it is shown that the scatterometer is able to provide similar long‐term statistics as available from buoy data, such as annual and monthly wind indexes. Such statistics is useful to give an overview of the climatology in the different areas. The correlation between QuikScat and in situ observations is degraded towards the coast, giving indication of how well the scatterometer can represent the coastal winds. The degradation is stronger in areas with strong spatial variability. The QuikScat winds are gridded into a 0.25° by 0.25° grid to produce seasonal and annual means of the offshore wind conditions over the Mediterranean. Copyright © 2010 John Wiley & Sons, Ltd.     

基于ERA5数据的江苏海域风能资源评估

利用欧洲中期天气预报中心（ECMWF）的ERA5风场数据，综合考虑风功率密度的时空分布、稳定性以及资源储量等要素，对江苏海域风能资源进行评估。结果表明，江苏海域多年平均风速和风功率密度总体呈现南高北低、离岸高近岸低的分布趋势。连云港近岸区域风功率密度等级小于2级，3级及以上区域主要分布在远海海域；盐城和南通除岸边潮间带滩涂区域外，大部分区域达到2级或3级，离岸约30 km可迅速提升至4级以上。风功率密度具有较明显的季节性分布特征；盐城南部和南通海域风能稳定性最好，连云港海域风能稳定性相对较差。南通和盐城南部风能资源有效储量最高，盐城北部次之，连云港最低。     

Effects of sea surface temperature accuracy on offshore wind resource assessment using a mesoscale model

Offshore wind simulations were performed with the Weather Research and Forecasting (WRF) model driven by three different sea surface temperature (SST) datasets for Japanese coastal waters to investigate the effect of the SST accuracies on offshore wind simulations. First, the National Centers for Environmental Prediction Final analysis (FNL) (1° × 1° grid resolution) and the Operational Sea Surface Temperature and Sea Ice Analysis (OSTIA) (0.05° × 0.05° grid resolution) datasets were compared with in situ measurements. The results show a decrease in accuracy of these datasets toward the coast from the open ocean. Aiming at an improved accuracy of SST data, we developed a new high‐resolution SST dataset (0.02° × 0.02° grid resolution). The new dataset referred to as MOSST is based on the Moderate Resolution Imaging Spectroradiometer (MODIS) product, provided by the Japan Aerospace Exploration Agency (JAXA). MOSST was confirmed to be more accurate than FNL and OSTIA for the coastal waters. Then, WRF simulations were carried out for 1 year with a 2 km grid resolution and by using the FNL, OSTIA and MOSST datasets. The use of the OSTIA dataset for a WRF simulation was found to improve the accuracy when compared with the FNL dataset, and further improvement was obtained when the MOSST dataset was applied. The sensitivity of wind speed and wind energy density to SST is also discussed. We conclude that the use of an accurate SST is a key factor not only for realistic offshore wind simulations near the surface but also for accurate wind resource assessments at the hub height of wind turbines. Copyright © 2014 John Wiley & Sons, Ltd.     

湍流风与浮冰联合作用下近海风力机动力学响应

以NREL 5 MW近海风力机为研究对象,基于Kaimal平稳随机风速谱模型建立风力机全域湍流风,同时采用Matlock模型计算动态冰力,模拟风力机所受冰激振动,研究在风-冰联合环境载荷作用下近海风力机动力学响应。结果表明:冰激振动极大地加剧塔顶各向振动;频域上,冰激振动影响主要集中于塔架1阶固有频率和叶片1阶摆振频率,且相应峰值与冰厚呈正相关关系;受冰激振动作用,塔架各向剪切力明显增加,且塔顶和塔基附近增幅大于塔身中部。     

中国沿海风电施工窗口期及功效分析

海上风电建设施工难度大、风险高,成本极难控制,其中工期是最大的可变成本。适应平价上网时代海上风电降本增效要求,本研究基于实测数据比较ERA5、CCMPv2、NCEP这3种再分析风场在中国近海的质量,并对SWAN模式进行适应性修正,在此基础上根据25 a(1996—2020年)逐小时风浪数值后报数据对山东半岛南至广西海上风电桩基施工和风电机组安装窗口期及功效的时空分布进行评估,并结合关键海域具体风电场进行讨论。结果表明：ERA5数据的质量最优;修正SWAN模式后报波浪要素的准确性得到提升;可施工桩基及安装风电机组数据在研究海域具有显著的时空变化特征。     

中尺度风资源数值模拟试验分析

应用中尺度数值模式模拟地区的风资源状况是一种比较先进的方法。该模拟成果对大范围区域风能资源的宏观评估和风电场宏观选址具有很好的参考价值。着重介绍了WRF(Weather Research and Forecast)数值模式模拟方法,并采用该模拟方法对近海风电场的风资源进行了模拟。