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In-Orbit Calibration Uncertainty of the Microwave Radiation Imager on board Fengyun-3C

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Journal of Meteorological Research 2021年第6期35卷 943-951页

作者： Xinxin XIE Wanting MENG Jiakai HE Weimin YU Xue LI School of Atmospheric Sciences Sun Yat-Sen UniversityZhuhai 519082 Key Laboratory of Tropical Atmosphere-Ocean System Ministry of EducationZhuhai 519082 Southern Marine Science and engineering Guangdong Laboratory(Zhuhai) Zhuhai 519082 Shanghai Spaceflight Institute ofTT&C and Telecommunication Shanghai 201109

This study evaluates the in-orbit calibration uncertainty(CU)for the microwave radiation imager(MWRI)on board the Chinese polar-orbiting meteorological satellite Fengyun-3 C(FY-3 C).Uncertainty analysis of the MWRI provides a direct link to the calibration system of the sensor and quantifies the calibration confidence based on the prelaunch and postlaunch *** unique design of the sensor makes the uncertainty in the calibration of the sensor highly correlate to the uncertainty in the brightness temperature(TB)measured at the hot view,while the cold view has negligible impacts on the calibration *** of knowledge on the emission of the hot-load reflector hampers the MWRI calibration accuracy significantly in the descending passes of the orbits when the hotload reflector is heated nonuniformly by the solar *** contamination originating from the satellite and in-orbit environments could enter the primary reflector via the hot view and further impinge on the CU,especially at the 10.65-GHz channels where the main-beam width is much broader than that of higher-frequency *** monthly-mean CU is lower than 2 K at all channels,depending on the observed earth scenes and in-orbit environments,and the month-to-month variation of CU is also noticed for all *** to the uncertainty in the emissive hot-load reflector,CU in the descending passes is generally larger than that in the ascending ***,up to 1-K CU difference between the ocean and land scenes is found for the 10.65-GHz channels,while this difference is less than 0.1 K at the 89-GHz channels.

关键词： calibration uncertainty(CU) microwave radiation imager(MWRI) Fengyun-3(FY-3)

Numerical investigation of the control factors driving Zhe-Min Coastal Current

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Acta Oceanologica Sinica 2022年第2期41卷 127-138页

作者： Yang Zhang Fei Chai Joseph Zhang Yang Ding Min Bao Yunwei Yan Hong Li Wei Yu Liang Chang State Key Laboratory of Satellite Ocean Environment Dynamics Second Institute of OceanographyMinistry of Natural ResourcesHangzhou 310012China Southern Marine Science and engineering Guangdong Laboratory(Zhuhai) Zhuhai 519080China School of Marine Sciences University of MaineOronoME 04469USA Virginia Institute of Marine Science College of William&Mary Center for Coastal Resource ManagementWilliamsburgVA 23185USA Physical Oceanography Laboratory Ocean University of ChinaQingdao 266100China Department of Atmospheric and Oceanic Sciences Institute of Atmospheric SciencesFudan UniversityShanghai 200438China College of Marine Sciences Shanghai Ocean UniversityShanghai 201306China

During the northeast monsoon season,Zhe-Min Coastal Current(ZMCC)travels along the Chinese mainland coast and carries fresh,cold,and eutrophic *** is significantly important for the hydrodynamic processes and marine ecosystems along its ***,this bottom-trapped plume deserves to be further discussed in terms of the major driving factor,for which different opinions *** this purpose,in this study,a high resolution Semi-implicit Cross-scale hydroscience Integrated System Model(SCHISM)is established and *** correlation coefficients exist between along-shelf wind speeds and seasonal variations of both ZMCC volume transport and the freshwater *** coefficients imply that the wind is important in regulating ***,for similar annual mean ZMCC volume transports,the extreme south boundaries of Zhe-Min Coastal Water(ZMCW)are different among different *** difference is attracting attention and is explored in this *** to the low wind/discharge experiment,it was found that although the volume transport of ZMCC is more sensitive to the variation of local wind speeds,the carried freshwater is limited by the Changjiang River discharge,which ultimately determines the south boundary of *** momentum analysis at transects I and II shows that,for driving ZMCC,the along-shore wind forcing is as important as the buoyancy *** that this conclusion is supported by a zero-discharge *** was also found that the buoyancy forcing varies with respect to time and space,which is due to variations of the discharge of Changjiang *** addition,a particle tracking experiment shows that the substance carried by the Changjiang River diluted water would distribute along the Zhe-Min coastal region during the northeast monsoon season and it may escape due to the wind relaxation.

关键词： coastal current numerical model momentum analysis Changjiang River diluted water East China Sea

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内部侵蚀过程中土体失稳现象与阈值分析

水力发电学报 2020年第2期39卷 44-51页

作者：冯晴枫傅旭东邵颂东清华大学水沙科学与水利水电工程国家重点实验室北京100084 Department of Civil and Structural engineering University of SheffieldSheffield S13JDUK

应用渗流-颗粒耦合的三维数值模型,计算分析土体的内部侵蚀过程。模型采用离散元法(DEM)计算颗粒运动过程,用有限体积法(FVM)计算渗流流场,颗粒运动与流场之间通过共用封闭项耦合。模型复演经典试验得到的颗粒体系流动-变形特性,并建立... 详细信息

应用渗流-颗粒耦合的三维数值模型,计算分析土体的内部侵蚀过程。模型采用离散元法(DEM)计算颗粒运动过程,用有限体积法(FVM)计算渗流流场,颗粒运动与流场之间通过共用封闭项耦合。模型复演经典试验得到的颗粒体系流动-变形特性,并建立了有效摩擦系数μeff与颗粒体系稳定性之间的联系,进而刻画了土体在水头阈值Hc下突发性失稳现象:当加载水头小于Hc时,μeff近似等于μ0,此时土体稳定,无内部侵蚀现象;当加载水头达到Hc时,μeff突增至μ1以上,此时土体突然失稳,内部侵蚀发生(μ0和μ1为计算率定值)。论文工作为深入认识堤防和土石坝中渗流侵蚀破坏机理提供了新的思路。

关键词：内部侵蚀数值模型流动-变形特性突发性失稳阈值

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多源降水数据的小流域水文模拟效用评估

干旱区地理 2020年第5期43卷 1179-1191页

作者：冯克鹏洪阳田军仓唐国强阚光远罗翔宇宁夏大学土木与水利工程学院宁夏银川750021 School of Civil engineering and Environmental Science University of OklahomaNormanOK 73072USA 宁夏节水灌溉与水资源调控工程技术研究中心宁夏银川750021 清华大学水沙科学与水利水电工程国家重点实验室北京100084 旱区现代农业水资源高效利用教育部工程研究中心宁夏银川750021

小流域是研究小微尺度水文水资源系统演变规律的理想对象,是用于计算河流产水产沙的最小单元,是水文及水土流失研究与管理的最佳地域尺度。通过遥感技术,气候模式获得降水数据,并驱动分布式水文模型,模拟和预测水文过程,是流域水文水资... 详细信息

小流域是研究小微尺度水文水资源系统演变规律的理想对象,是用于计算河流产水产沙的最小单元,是水文及水土流失研究与管理的最佳地域尺度。通过遥感技术,气候模式获得降水数据,并驱动分布式水文模型,模拟和预测水文过程,是流域水文水资源研究的必然趋势。以NOAA-CPC-US降水作为参照,在美国不同地区的9个小流域,评估卫星降水产品PERSIANN,PERSIANN-CDR,TRMM-3B42V7,GPM-IMERG,雷达降水StageIV以及气候模式ERA5降水产品的精度,并用这7种降水产品驱动CREST分布式水文模型,评估了7种降水产品的水文模拟效用。研究表明:各降水产品与NOAA-CPC-US降水吻合程度从高到低,依次是StageIV雷达降水,PERSIANNCDR和GPM-IMERG次之,再次是PERSIANN和ERA5,最后是TRMM-3B42V7。各降水产品在美国北部高纬度地区和西部山地等区域的小流域降水估算精度略低,在美国中部,南部,东部的小流域有较好的降水精度。在水文模拟效用评估中,设定相同率定期,分别使用7种降水产品率定CREST模型参数,得到率定参数集后,在相同验证期对流域日径流过程进行模拟。结果表明:NOAA-CPC-US和Stage IV雷达降水在各小流域水文模拟中效果较好,在美国北部和西部地区,使用PERSIANN,PERSIANN-CDR,GPM-IMERG,ERA5降水进行水文模拟时需要谨慎。TRMM-3B42V7的小流域水文模拟效果不理想。

关键词：小流域 CREST水文模型多源降水水文模拟