Evaluation of dynamically downscaled reanalysis precipitation data for hydrological application          下载免费PDF全文

Satish Bastola  Vasubandhu Misra 《水文研究》2014,28(4):1989-2002

Skilful and reliable precipitation data are essential for seasonal hydrologic forecasting and generation of hydrological data. Although output from dynamic downscaling methods is used for hydrological application, the existence of systematic errors in dynamically downscaled data adversely affects the skill of hydrologic forecasting. This study evaluates the precipitation data derived by dynamically downscaling the global atmospheric reanalysis data by propagating them through three hydrological models. Hydrological models are calibrated for 28 watersheds located across the southeastern United States that is minimally affected by human intervention. Calibrated hydrological models are forced with five different types of datasets: global atmospheric reanalysis (National Centers for Environmental Prediction/Department of Energy Global Reanalysis and European Centre for Medium‐Range Weather Forecasts 40‐year Reanalysis) at their native resolution; dynamically downscaled global atmospheric reanalysis at 10‐km grid resolution; stochastically generated data from weather generator; bias‐corrected dynamically downscaled; and bias‐corrected global reanalysis. The reanalysis products are considered as surrogates for large‐scale observations. Our study indicates that over the 28 watersheds in the southeastern United States, the simulated hydrological response to the bias‐corrected dynamically downscaled data is superior to the other four meteorological datasets. In comparison with synthetically generated meteorological forcing (from weather generator), the dynamically downscaled data from global atmospheric reanalysis result in more realistic hydrological simulations. Therefore, we conclude that dynamical downscaling of global reanalysis, which offers data for sufficient number of years (in this case 22 years), although resource intensive, is relatively more useful than other sources of meteorological data with comparable period in simulating realistic hydrological response at watershed scales. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   

Comparison of EnOI and EnKF regional ocean reanalysis systems     

《Ocean Modelling》2015

This study compares two regional eddy resolving ocean reanalysis systems, based on the ensemble Kalman filter (EnKF) and ensemble optimal interpolation (EnOI), focusing on data assimilation aspects. Both systems are configured for the Tasman Sea using the same ocean model with 0.1° resolution and commonly available observations of satellite altimetry, sea surface temperature and subsurface temperature and salinity. The primary goals are to quantify the difference in performance of the EnKF and EnOI and investigate how important this difference might be from an oceanographic perspective. We find that both systems generally constrain mesoscale circulation in the region, with some exceptions for the East Australian Current separation region, the most energetic and chaotic part of the domain. Overall, the EnKF is found to consistently outperform the EnOI, producing on average 9–21% smaller innovations. The EnKF also has better forecast skill relative to the persisted analysis than the EnOI. For SST the EnKF forecast outperforms persisted analysis by about 17%, which indicates that the surface circulation is mainly constrained. The EnKF and EnOI are shown to produce qualitatively different increments of unobserved or sparsely observed variables; however, we find only moderate improvements of the EnKF over EnOI in subsurface temperature fields when compared against withheld XBT observations. We attribute this lack of a major improvement in subsurface reconstruction to the inability of the EnKF to linearly constrain the system due to initialisation shock, model error caused by open boundaries, and possibly insufficient observations.  相似文献   

ERA-Interim 再分析数据在中国沿海的质量评估   总被引：5，自引：0，他引：5  

高志刚  骆敬新  刘克修  张庆河  范文静  武双全  李响 《海洋科学》2015,39(5):92-105

本文采用1979~2012年的中国沿海台站观测数据对ERA-Interim(简称"ERA-I")的气温、气压和海温数据进行质量评估。结果表明:(1)从常年平均来看,ERA-I气温、气压和海温多年月平均变化与观测数据吻合较好,可以反映气候态的季节变化特征。与台站观测数据相比,ERA-I气温平均偏高0.19℃,气压平均偏低0.17 h Pa,海温平均偏高0.70℃。(2)从年际变化情况来看,ERA-I和台站观测的气温、气压和海温变化趋势一致,气温和海温呈上升趋势,气压呈下降趋势。但在海南岛附近使用ERA-I气温做年际变化分析和在东海台湾海峡至北部湾沿岸使用ERA-I海温做年际变化趋势分析时要谨慎。(3)从月均变化分析来看,ERA-I月均气温、气压和海温数据与台站实测数据具有很好的一致性。从误差空间分布来看,ERA-I气温在黄海沿岸平均误差最小,ERA-I气压在渤海沿岸平均误差最小,ERA-I海温在南海沿岸平均误差最小。需要特别指出的是,ERA-I月均海温在渤海和台湾海峡附近沿岸平均误差较大(部分站均方根误差超过2.5℃),在上述区域使用ERA-I海温数据时应考虑其产品偏差。  相似文献   

COMPARISONS OF THE WEST PACIFIC SUBTROPICAL HIGH AND THE SOUTH ASIA HIGH BETWEEN NCEP/NCAR AND ECMWF REANALYSIS DATASETS     

陈雯  智协飞 《热带气象学报(英文版)》2008,14(2):121-124

Comparisons of the west Pacific subtropical high with the South Asia High are made using the NCEP/NCAR and ECMWF 500 hPa and 100 hPa monthly boreal geopotential height fields for the period 1961 - 2000. Discrepancies are found for the time prior to 1980. The west Pacific subtropical high in the NCEP/NCAR data is less intense than in ECMWF data before 1980. The range and strength of the west Pacific subtropical high variation described by the NCEP/NCAR data are larger than those depicted by ECMWF data. The same situation appears in the 100-hPa geopotential field. These discoveries suggest that the interdecadal variation of the two systems as shown by the NCEP/NCAR data may not be true. Besides, the South Asia High center in the NCEP/NCAR data is obviously stronger than in the ECMWF data during the periods 1969, 1979 - 1991 and 1992 - 1995. Furthermore, the range is larger from 1992 to 1995.  相似文献   

马斯克林高压的变化特征   总被引：3，自引：0，他引：3  

崔锦  杨修群  张爱忠 《气象科技》2008,36(1):35-42

利用历史天气图和NCEP再分析资料,普查了1980～2002年出现在华北平原地区的回流天气过程.依据500 hPa环流形势,对华北平原的回流天气形势分为两种:两槽一脊型和高纬低压带型.针对不同的天气分型对产生回流天气的动力条件、水汽来源进行了合成诊断分析.结果表明:涡度和散度的垂直分布与一般的降水过程不同,低层存在辐散和反气旋环流;自东北南下经渤海回流到华北平原的空气是比较干的.该文分析结果有助于预报业务人员了解回流天气,提高华北回流天气的预报准确率.  相似文献   

几种再分析地表气压资料在中国区域的适用性评估   总被引：5，自引：1，他引：4       下载免费PDF全文

赵天保  华丽娟 《应用气象学报》2009,20(1):70-79

应用台站观测资料对ERA-40, NCEP/NCAR以及NCEP/DOE再分析地表气压产品在中国不同区域、不同年代和不同季节的适用性进行了评估。分析发现, 几种再分析产品虽然能在一定程度上反映出观测资料所具有的时空分布特征, 但它们之间的差异却具有明显的区域和季节变化特征, 即冬季小而夏季大、东部地区小而西部地区大; 同时还发现ERA-40和NCEP/NCAR再分析产品在20世纪70年代以前均与观测资料有相对较大的差别, 特别是NCEP/NCAR在70年代以前的夏季气压值过于偏低, 从而夸大了很多地区的年代际变化特征。相比而言, ERA-40地表气压的长期变化趋势以及时空演变规律在中国大多数地区要优于NCEP/NCAR再分析产品, 特别是在中国西部地区。分析还表明, NCEP/DOE虽与观测资料存在一定的系统性偏差, 却与另外两种再分析产品有着较为相似的年际变化特征及趋势。  相似文献   

对三套再分析资料中国大陆地区夏季降水量的评估分析   总被引：3，自引：0，他引：3  

李建  宇如聪  陈昊明  原韦华 《气象》2010,36(12):1-9

以中国台站降水为参照,评估分析了三套再分析资料(NCEP/DOE,ERA和JRA)对中国夏季降水场的再现能力。结果显示,三套资料均能基本再现夏季降水量分布的主要特征,亦能较好刻画大部分地区降水的年际和季节内变化特征,但同时也存在诸多问题:NCEP资料在青藏高原东坡存在一个虚假降水中心,且对中西部和西南地区夏季降水的季节内演变特征再现能力较差;ERA资料降水量系统性偏小,且不能合理描述中西部地区降水的年际变化;JRA资料高估了华南沿海地区的降水量。三套资料均存在高估弱降水、低估强降水的问题。对日降水量≥0.1 mm的降水事件进行TS、BS评分,三套资料的TS评分在0.6左右,BS评分在1.5左右;随着参与评分的降水等级的提升,两项评分都迅速下降,三套资料对暴雨的预报评分都非常低。通过分析可了解当前较先进的数值预报模式在基本真实的环流场强迫下对我国夏季降水的预报能力,认识模式中物理参数化过程导致的模拟偏差,为模式发展和评估提供参照。  相似文献   

Validation of ECMWF and NCEP–NCAR Reanalysis Data in Antarctica   总被引：3，自引：0，他引：3  

YU Lejiang  ZHANG Zhanhai  ZHOU Mingyu  Shiyuan ZHONG  Donald LENSCHOW  Hsiaoming HSU  WU Huiding  SUN Bo 《大气科学进展》2010,27(5):1151-1168

The European Center for Medium-Range Weather Forecast (ECMWF) Re-Analysis (ERA-40) and the National Centers for Environmental Prediction-National Center for Atmospheric Research (NCEP-NCAR) ECMWF (ERA-40) and NCEP-NCAR reanalysis data were compared with Antarctic station observations, including surface-layer and upper-layer atmospheric observations, on intraseasonal and interannual timescales. At the interannual timescale, atmospheric pressure at different height levels in the ERA-40 data are in better agre...  相似文献   

NCEP/NCAR再分析温度资料在农业气象中的应用可行性   总被引：3，自引：1，他引：3  

李兆芹  姚益平  姚克敏 《南京气象学院学报》2004,27(3):420-427

为探讨NCEP/NCAR再分析温度网格资料在农业气象研究中的应用价值,以北京、南京、广州、昆明、郑州和三亚6个气象台站的实测地面气象资料为依据,证明了NCEP/NCAR再分析温度网格资料的可靠性。进一步用Cressman插值、双线性二次插值、抛物线二次插值以及先抛物线插值后线性插值等4种插值方法,用NCEP/NCAR再分析温度网格资料对上述6站的地面日平均气温进行了插值计算,并对不同插值方法的结果作了比较。结果表明,站点纬度较高时(30°N以北),应用双线性二次内插法插值效果较好,精度略低;站点纬度较低时(30°N以南),应用Cressman插值法插值效果好,精度也高。这可能是较高纬度缺测资料较多造成的。利用NCEP/NCAR再分析网格温度插值资料分析两系法杂交水稻在泰国的制种气候适应性证明该资料在农业气象研究中是可以应用的。  相似文献   

NCEP和ECMWF资料表征南海夏季风的差异   总被引：2，自引：2，他引：2  

郑彬  谷德军  李春晖 《热带气象学报》2006,22(3):217-222

比较美国国家环境预报中心（NCEP）和欧洲中期天气预报中心（ECMWF）的再分析资料,分析了二者用低层风场表征南海夏季风上的差异.结果表明,NCEP得到的南海夏季风指数有明显的减小趋势,而ECMWF则没有;二者在年际尺度上都能较好地表征南海夏季风强度,而年代际尺度上有明显的位相差.与西沙站的探空资料比较结果表明,NCEP在经向风上更接近观测资料,而经向风的趋势变化正是西沙站西南风减小趋势的主要贡献项;ECMWF资料在年代际尺度变化上更接近观测资料.与1998年南海夏季风试验SCSMEX的再分析资料比较显示,NCEP资料在空间上与SCSMEX资料更相似.  相似文献