检索结果-南通市图书馆

Vector Radiative Transfer in a Vertically Inhomogeneous Scattering and Emitting Atmosphere.PartⅠ:A New Discrete Ordinate Method

引用

Journal of Meteorological Research 2024年第2期38卷 209-224页

作者： Ziqiang ZHU fuzhong weng Yang HAN Chinese Academy of Meteorological Sciences China Meteorological AdministrationBeijing 100081 University of Chinese Academy of Sciences Beijing 100049 CMA Earth System Modeling and Prediction Centre China Meteorological Administration(CMA)Beijing 100081 State Key Laboratory of Severe Weather Chinese Academy of Meteorological SciencesChina Meteorological AdministrationBeijing 100081

The original vector discrete ordinate radiative transfer(VDISORT)model takes into account Stokes radiance vector but derives its solution assuming azimuthal symmetric surface reflective matrix and atmospheric scattering phase matrix,such as the phase matrix derived from spherical particles or randomly oriented non-spherical particles.In this study,a new VDISORT is developed for general atmospheric scattering and boundary conditions.Stokes vector is decomposed into both sinusoidal and cosinusoidal harmonic modes,and the radiance at arbitrary viewing geometry is solved directly by adding two zero-weighted points in the Gaussian quadrature scheme.The complex eigenvalues in homogeneous solutions are also taken into full consideration.The accuracy of VDISORT model is comprehensively validated by four cases:Rayleigh scattering case,the spherical particle scattering case with the Legendre expansion coefficients of 0th-13th orders of the phase matrix(hereinafter L13),L13 with a polarized source,and the randomoriented oblate particle scattering case with the Legendre expansion coefficients of 0th-11th orders of the phase matrix(hereinafter L11).In all cases,the simulated radiances agree well with the benchmarks,with absolute biases less than 0.0065,0.0006,and 0.0008 for Rayleigh,unpolarized L13,and L11,respectively.Since a polarized bidirectional reflection distribution function(pBRDF)matrix is used as the lower boundary condition,VDISORT is now able to handle fully coupled atmospheric and surface polarimetric radiative transfer processes.

关键词： radiative transfer discrete ordinate polarization Stokes vector vector discrete ordinate radiative transfer(VDISORT)

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Cloud-Type-Dependent 1DVAR Algorithm for Retrieving Hydrometeors and Precipitation in Tropical Cyclone Nanmadol from GMI Data

引用

Advances in Atmospheric Sciences 2024年第3期41卷 407-419页

作者： Linjun HAN fuzhong weng Hao HU Xiuqing HU School of the Environment China University of Geosciences(Wuhan)Wuhan 430074China Chinese Academy of Meteorological Sciences Beijing 100081China CMA Earth System Modeling and Prediction Centre Beijing 100081China Key Laboratory of Radiometric Calibration and Validation for Environmental Satellites National Satellite Meteorological Center(National Center for Space Weather)of CMABeijing 100081China

Understanding the structure of tropical cyclone(TC)hydrometeors is crucial for detecting the changes in the distribution and intensity of precipitation.In this study,the GMI brightness temperature and cloud-dependent 1DVAR algorithm were used to retrieve the hydrometeor profiles and surface rain rate of TC Nanmadol(2022).The Advanced Radiative Transfer Modeling System(ARMS)was used to calculate the Jacobian and degrees of freedom(△DOF)of cloud water,rainwater,and graupel for different channels of GMI in convective conditions.The retrieval results were compared with the Dual-frequency Precipitation Radar(DPR),GMI 2A,and IMERG products.It is shown that from all channels of GMI,rain water has the highest△DOF,at 1.72.According to the radiance Jacobian to atmospheric state variables,cloud water emission dominates its scattering.For rain water,the emission of channels 1–4 dominates scattering.Compared with the GMI 2A precipitation product,the 1DVAR precipitation rate has a higher correlation coefficient(0.713)with the IMERG product and can better reflect the location of TC precipitation.Near the TC eyewall,the highest radar echo top indicates strong convection.Near the melting layer where Ka-band attenuation is strong,the double frequency difference of DPR data reflects the location of the melting.The DPR drop size distribution(DSD)product shows that there is a significant increase in particle size below the melting layer in the spiral rain band.Thus,the particle size may be one of the main reasons for the smaller rain water below the melting layer retrieved from 1DVAR.

关键词： cloud-dependent 1DVAR hydrometeor precipitation GMI DPR

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Improved Microwave Ocean Emissivity and Reflectivity Models Derived from Two-Scale Roughness Theory

引用

Advances in Atmospheric Sciences 2023年第10期40卷 1923-1938页

作者： Lingli HE fuzhong weng Chinese Academy of Meteorological Sciences Beijing 100081China University of Chinese Academy of Sciences Beijing 100049China CMA Earth System Modeling and Prediction Centre Beijing 100081China

The Geometrical Optics(GO)approach and the FAST Emissivity Model(FASTEM)are widely used to estimate the surface radiative components in atmospheric radiative transfer simulations,but their applications are limited in specific conditions.In this study,a two-scale reflectivity model(TSRM)and a two-scale emissivity model(TSEM)are developed from the two-scale roughness theory.Unlike GO which only computes six non-zero elements in the reflectivity matrix,The TSRM includes 16 elements of Stokes reflectivity matrix which are important for improving radiative transfer simulation accuracy in a scattering atmosphere.It covers the frequency range from L-to W-bands.The dependences of all TSRM elements on zenith angle,wind speed,and frequency are derived and analyzed in details.For a set of downwelling radiances in microwave frequencies,the reflected upwelling brightness temperature(BTs)are calculated from both TSRM and GO and compared for analyzing their discrepancies.The TSRM not only includes the effects of GO but also accounts for the small-scale Bragg scattering effect in an order of several degrees in Kelvins in brightness temperature.Also,the third and fourth components of the Stokes vector can only be produced from the TSRM.For the emitted radiation,BT differences in vertical polarization between a TSEM and FASTEM are generally less than 5 K when the satellite zenith angle is less than 40°,whereas those for the horizontal component can be quite significant,greater than 20 K.

关键词： emissivity microwave remote sensing reflectivity matrix two-scale roughness theory

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Estimation of Terrestrial Net Primary Productivity in China from Fengyun-3D Satellite Data

引用

Journal of Meteorological Research 2022年第3期36卷 401-416页

作者： Yonghong LIU Xiuzhen HAN fuzhong weng Yongming XU Yeping ZHANG Shihao TANG Earth System Modeling and Prediction Center China Meteorological AdministrationBeijing 100081 State Key Laboratory of Severe Weather Chinese Academy of Meteorological SciencesChina Meteorological AdministrationBeijing 100081 National Satellite Meteorological Center China Meteorological AdministrationBeijing 100081 School of Remote Sensing and Geomatics Engineering Nanjing University of Information Science&TechnologyNanjing 210044

Currently,the satellite data used to estimate terrestrial net primary productivity(NPP)in China are predominantly from foreign satellites,and very few studies have based their estimates on data from China’s Fengyun satellites.Moreover,despite their importance,the influence of land cover types and the normalized difference vegetation index(NDVI)on NPP estimation has not been clarified.This study employs the Carnegie–Ames–Stanford approach(CASA)model to compute the fraction of absorbed photosynthetically active radiation and the maximum light use efficiency suitable for the main vegetation types in China in accordance with the finer resolution observation and monitoring-global land cover(FROM-GLC)classification product.Then,the NPP is estimated from the Fengyun-3D(FY-3D)data and compared with the Moderate Resolution Imaging Spectroradiometer(MODIS)NPP product.The FY-3D NPP is also validated with existing research results and historical field-measured NPP data.In addition,the effects of land cover types and the NDVI on NPP estimation are analyzed.The results show that the CASA model and the FY-3D satellite data estimate an average NPP of 441.2 g C m^(−2) yr^(−1) in 2019 for China’s terrestrial vegetation,while the total NPP is 3.19 Pg C yr^(−1).Compared with the MODIS NPP,the FY-3D NPP is overestimated in areas of low vegetation productivity and is underestimated in high-productivity areas.These discrepancies are largely due to the differences between the FY-3D NDVI and MODIS NDVI.Compared with historical field-measured data,the FY-3D NPP estimation results outperformed the MODIS NPP results,although the deviation between the FY-3D NPP estimate and the in-situ measurement was large and may exceed 20%at the pixel scale.The land cover types and the NDVI significantly affected the spatial distribution of NPP and accounted for NPP deviations of 17.0%and 18.1%,respectively.Additionally,the total deviation resulting from the two factors reached 29.5%.These results show that accurate NDVI products and land cover types are

关键词： net primary productivity(NPP) Carnegie-Ames-Stanford approach(CASA)model maximum light use efficiency Fengyun-3D(FY-3D) finer resolution observation and monitoring-global land cover(FROM-GLC)land cover types Moderate Resolution Imaging Spectroradiometer(MODIS)

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Assimilation of FY-3D MWTS-Ⅱ Radiance with 3D Precipitation Detection and the Impacts on Typhoon Forecasts

引用

Advances in Atmospheric Sciences 2023年第5期40卷 900-919页

作者： Luyao QIN Yaodeng CHEN Gang MA fuzhong weng Deming MENG Peng ZHANG Key Laboratory of Meteorological Disaster of Ministry of Education(KLME)/Joint International Research Laboratory of Climate and Environment Change(ILCEC)/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters(CIC-FEMD) Nanjing University of Information Science&TechnologyNanjing 210044China Earth System Modeling and Prediction Centre China Meteorological AdministrationBeijing 100081China Key Laboratory of Radiometric Calibration and Validation for Environmental Satellites(LRCVES/CMA) National Satellite Meteorological CenterChina Meteorological Administration(NSMC/CMA)Beijing 100081China

Precipitation detection is an essential step in radiance assimilation because the uncertainties in precipitation would affect the radiative transfer calculation and observation errors.The traditional precipitation detection method for microwave only detects clouds and precipitation horizontally,without considering the three-dimensional distribution of clouds.Extending precipitation detection from 2D to 3D is expected to bring more useful information to the data assimilation without using the all-sky approach.In this study,the 3D precipitation detection method is adopted to assimilate Microwave Temperature Sounder-2(MWTS-Ⅱ)onboard the Fengyun-3D,which can dynamically detect the channels above precipitating clouds by considering the near-real-time cloud parameters.Cycling data assimilation and forecasting experiments for Typhoons Lekima(2019)and Mitag(2019)are carried out.Compared with the control experiment,the quantity of assimilated data with the 3D precipitation detection increases by approximately 23%.The quality of the additional MWTS-Ⅱradiance data is close to the clear-sky data.The case studies show that the average root-mean-square errors(RMSE)of prognostic variables are reduced by 1.7%in the upper troposphere,leading to an average reduction of4.53%in typhoon track forecasts.The detailed diagnoses of Typhoon Lekima(2019)further show that the additional MWTS-Ⅱradiances brought by the 3D precipitation detection facilitate portraying a more reasonable circulation situation,thus providing more precise structures.This paper preliminarily proves that 3D precipitation detection has potential added value for increasing satellite data utilization and improving typhoon forecasts.

关键词： numerical weather prediction radiance assimilation microwave temperature sounding FY-3D MWTS-II precipitation detection

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Random Forest-Based Snow Cover Mapping in China Using Fengyun-3B VIRR Data

引用

Journal of Meteorological Research 2023年第5期37卷 666-689页

作者： Yuchen XIE Yonghong LIU Yeping ZHANG fuzhong weng Shanyou ZHU Zhaojun ZHENG Shihao TANG School of Remote Sensing&Geomatics Engineering Nanjing University of Information Science&TechnologyNanjing 210044 CMA Earth System Modeling and Prediction Centre China Meteorological Administration(CMA)Beijing 100081 State Key Laboratory of Severe Weather Chinese Academy of Meteorological SciencesChina Meteorological AdministrationBeijing 100081 National Satellite Meteorological Centre China Meteorological AdministrationBeijing 100081

Currently,there is variability in the spectral band thresholds for snow cover recognition using remote sensing in different regions and for complex terrains.Using Fengyun-3B Visible and Infra-Red Radiometer(FY-3B VIRR)satellite data,we applied random forest(RF)methodology and selected 13 feature variables to obtain snow cover.A training set was generated,containing approximately 1 million snow and nonsnow samples obtained in China from the snow monitoring reports issued by the National Satellite Meteorological Centre and four snow cover products from the Interactive Multi-sensor Snow and Ice Mapping System(IMS),the FY-3B Multi-Sensor Synergy(MULSS),the Moderate Resolution Imaging Spectroradiometer(MODIS)snow cover product(MYD10A1),and the National Cryosphere Desert Data Center(NCDC).This training set contained many different samples of cloud types and snow under forest cover to help effectively distinguish snow and clouds and improve the recognition rate of snow under forest cover.Then,two RF snow cover recognition models were constructed for the snow and nonsnow seasons and they were used to conduct daily snow cover recognition in China from 2011 to 2020.The results show that the RF models constructed based on FY-3B VIRR data have good recognition performance for shallow snow,understory snow,and snow on the Qinghai–Tibetan Plateau.The recognition accuracy against weather stations and the spatial consistency with the IMS product are better than the MULSS,MYD10A1,and NCDC products.The overall accuracy of the RF product is 90.6%,and the recall rate is 93.8%.The omission and commission errors are 6.2%and11.1%,respectively.Unlike other existing snow cover algorithms,the established RF model skips the complicated atmospheric correction and cloud identification processes and does not involve external auxiliary data;thus,it is more easily popularized and operationally applicable to generating long-time series snow cover products.

关键词： snow identification random forest Fengyun-3B Visible and Infra-Red Radiometer feature selection

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Impacts of the Urban Spatial Landscape in Beijing on Surface and Canopy Urban Heat Islands

引用

Journal of Meteorological Research 2022年第6期36卷 882-899页

作者： Yonghong LIU Yongming XU Yeping ZHANG Xiuzhen HAN fuzhong weng Chunyi XUAN Wenjun SHU CMA Earth System Modeling and Prediction Centre China Meteorological Administration(CMA)Beijing 100081 State Key Laboratory of Severe Weather Chinese Academy of Meteorological SciencesChina Meteorological AdministrationBeijing 100081 School of Remote Sensing and Geomatics Engineering Nanjing University of Information Science&TechnologyNanjing 210044 National Satellite Meteorological Centre China Meteorological AdministrationBeijing 100081 Beijing Municipal ClimateCentre Beijing Meteorological ServiceBeijing 100089

How does the urban spatial landscape(USL)pattern affect the land surface urban heat islands(SUHIs)and canopy urban heat islands(CUHIs)?Based on satellite and meteorological observations,this case study compares the impacts of the USL pattern on SUHI and CUHI in the central urban area(CUA)of Beijing using the satellite land-surface-temperature product and hourly temperature data from automatic meteorological stations from 2009 to 2018.Eleven USL metrics—building height(BH),building density(BD),standard deviation of building height(BSD),floor area ratio(FAR),frontal area index(FAI),roughness length(RL),sky view factor(SVF),urban fractal dimension(FD),vegetation coverage(VC),impervious coverage(IC),and albedo(AB)—with a 500-m spatial resolution in the CUA are extracted for comparative analysis.The results show that SUHI is higher than CUHI at night,and SUHI is only consistent with CUHI at spatial-temporal scales at night,particularly in winter.Spatially,all 11 metrics are strongly correlated with both the SUHI and CUHI at night,with stronger correlation between most metrics and SUHI.VC,AB,and SVF have the greatest impact on both the SUHI and CUHI.High SUHI and CUHI values tend to appear in areas with BD≥0.26,VC≤0.09,AB≤0.09,and SVF≤0.67.In summer,most metrics have a greater impact on the SUHI than CUHI;the opposite is observed in winter.SUHI variation is affected primarily by VC in summer and by VC and AB in winter,which is different for the CUHI variation.The collective contribution of all 11metrics to SUHI spatial variation in summer(61.8%)is higher than that to CUHI;however,the opposite holds in winter and for the entire year,where the cumulative contribution of the factors accounts for 66.6%and 49.6%,respectively,of the SUHI variation.

关键词： surface urban heat island canopy urban heat island vegetation coverage albedo sky view factor building density Beijing

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Applications of AMSR-E Measurements for Tropical Cyclone Predictions PartⅠ: Retrieval of Sea Surface Temperature and Wind Speed

引用

Advances in Atmospheric Sciences 2008年第2期25卷 227-245页

作者： Banghua YAN fuzhong weng NOAA Joint Center for Satellite Data Assimilation Camp Springs MD USA NOAA/NESDIS/Center for Satellite Applications and Research Camp Springs MD USA

Existing satellite microwave algorithms for retrieving Sea Surface Temperature （SST） and Wind （SSW） are applicable primarily for non-raining cloudy conditions. With the launch of the Earth Observing System （EOS） Aqua satellite in 2002, the Advanced Microwave Scanning Radiometer （AMSRoE） onboard provides some unique measurements at lower frequencies which are sensitive to ocean surface parameters under adverse weather conditions. In this study, a new algorithm is developed to derive SST and SSW for hurricane predictions such as hurricane vortex analysis from the AMSRoE measurements at 6.925 and 10.65 GHz. In the algorithm, the effects of precipitation emission and scattering on the measurements are properly taken into account. The algorithm performances are evaluated with buoy measurements and aircraft dropsonde data. It is found that the root mean square （RMS） errors for SST and SSW are about 1.8 K and 1.9 m s^- 1, respectively, when the results are compared with the buoy data over open oceans under precipitating clouds （e.g., its liquid water path is larger than 0.5 mm）, while they are 1.1 K for SST and 2.0 m s^-1 for SSW, respectively, when the retrievals are validated against the dropsonde measurements over warm oceans. These results indicate that our newly developed algorithm can provide some critical surface information for tropical cycle predictions. Currently, this newly developed algorithm has been implemented into the hybrid variational scheme for the hurricane vortex analysis to provide predictions of SST and SSW fields.

关键词： Ocean surface temperature ocean surface wind AMSR-E hurricane vortex analysis

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Clinical characteristics of postoperative necrotizing enterocolitis in patients with congenital jejunoileal atresia and its risk factors

引用

World Journal of Pediatric Surgery 2024年第1期7卷 42-46页

作者： Xiaofeng Xiong Wei Lu fuzhong Xing Yuan Cai Jixin Yang Yuhang Yuan Jiexiong Feng Xuyong Chen Department of Pediatric Surgery Tongji Hospital of Tongji Medical College of Huazhong University of Science and TechnologyWuhanHubeiChina Department of Neonate Surgery Wuhan Children's HospitalHuazhong University of Science and TechnologyWuhanHubeiChina Department of Pediatric Surgery The First Affiliated Hospital of Zhengzhou UniversityZhengzhouHenanChina

Objective To review postoperative necrotizing enterocolitis(NEC)in patients with jejunoileal atresia(JIA)and to explore the potential risk factors related to the concurrence ofNEC.Methods Patients diagnosed with JIA who received surgical treatment from January 2016 to June 2021 were enrolled.Demographics,viral infection of the fetus,transfusion within 48 hours before NEC,sepsis before JIA repair,pathological and anatomical classification of JIA,combined malformation,occurrence time of NEC after the operation,treatment,and prognosis of patients were analyzed.Patients were divided into NEC group and non-NEC group,and all patients were followed up for 3-6 months to observe for complications.Results A total of 180 patients with JIA were included,of whom 12 were diagnosed with NEC after surgery and 1 patient with NEC died during follow-up.The average age,birth weight,gestational age,proportion of premature infants,proportion of preoperative infections,and pathological classification of JIA did not significantly differ between the two groups.The probability of patients with proximal jejunal atresia(PJA)in the NEC group(58.3%)was higher than that in the non-NEC group(22.6%)(p=0.011),and patients with PJA had longer parenteral nutrition time than patients without PJA(26.64±9.21 days vs 15.11±6.58 days,p<0.001).Conclusion PJA was more likely to be associated with concurrent NEC after surgery,which is a highly NEC-related risk factor inherent in JIA.

关键词： patients postoperative transfusion

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Remote Sensing of Tropical Cyclone Thermal Structure from Satellite Microwave Sounding Instruments:Impacts of Optimal Channel Selection on Retrievals

引用

Journal of Meteorological Research 2018年第5期32卷 804-818页

作者： Yang HAN fuzhong weng Nanjing University of Information Science&Technology Nanjing 210044 State Key Laboratory of Severe Weather Chinese Academy of Meteorological SciencesBeijing 100081

Accurate information on atmospheric temperature of tropical cyclones （TCs） is important for monitoring and pre- diction of their developments and evolution. For hurricanes, temperature anomaly in the upper troposphere can be de-rived from Advanced Microwave Sounding Unit （AMSU） and Advanced Technology Microwave Sounder （ATMS） through either regression-based or variational retrieval algorithms. This study investigates the dependency of TC warm core structure on emission and scattering processes in the forward operator used for radiance computations in temperature retrievals. In particular, the precipitation scattering at ATMS high-frequency channels can significantly change the retrieval outcomes. The simulation results in this study reveal that the brightness temperatures at 183 GHz could be depressed by 30-50 K under cloud ice water path of 1.5 mm, and thus, the temperature structure in hur-ricane atmosphere could be distorted if the ice cloud scattering was inaccurately characterized in the retrieval system. It is found that for Hurricanes Irma, Maria, and Harvey that occurred in 2017, their warm core anomalies retrieved from ATMS temperature sounding channels 4 15 were more reasonable and realistic, compared with the retrievals from all other channel combinations and earlier hurricane simulation results.

关键词： Advanced Technology Microwave Sounder （ATMS） Microwave Retrieval Testbed （MRT） Warm core hurricane Irma Maria Harvey

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：