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Performance evaluation of the TRMM precipitation estimation using ground-based radars from the GPM validation network

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JOURNAL OF ATMOSPHERIC AND SOLAR-TERRESTRIAL PHYSICS 2012年 77卷 194-208页

作者： Islam, Tanvir Rico-Ramirez, Miguel A. Han, Dawei Srivastava, Prashant K. Ishak, Asnor M. Univ Bristol Dept Civil Engn Bristol Avon England

The Global Precipitation Measurement (GPM) mission is scheduled to fly in the year of 2013 to measure the earth's precipitation structure. Since the precipitation measurement by the GPM platform will be very similar to its predecessor, the Tropical Rainfall Measuring Mission (TRMM), hence, the development of GPM algorithms to improve precipitation retrievals can be addressed through the lessons learnt from the former TRMM mission in terms of precipitation retrievals and its associated uncertainty. To support the future GPM mission, this paper assesses the performance of the TRMM precipitation estimation using ground-based radars from the GPM validation network. A total of 22 significant overpass instantaneous events from 22 different radar sites has been evaluated in view of different surface and rain type flags. The overall results show that attenuation corrected reflectivity from the TRMM precipitation radar agrees well to the measured reflectivity from ground based radars with correlation coefficients r=0.91 (without frequency adjustment) and r=0.92 (with frequency adjustment). However, the correlation decreases by 10-30%, once the reflectivity are transformed to rainfall rates. The lower correlations on the basis of precipitation estimation by the TRMM are exhibited over the coast than those of ocean and land surface terrain. Taking into account the rain type flags, the analysis shows a poor correlation during convective precipitations, in particular, those retrieved from the TRMM precipitation radar. In contrast, the combined algorithm, which utilizes both radar and microwave imager instrument on-board TRMM, outperforms throughout the analysis, yet, there is a scope to improve the precipitation retrievals. (C) 2012 Elsevier Ltd. All rights reserved.

关键词： Microwave remote sensing Reflectivity Global rainfall Satellite mission Ground validation retrieval algorithms Active and passive NEXRAD (WSR-88D) Stratiform and convective Rainfall variability

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An Integrated Examination of AMSR2 Products Over Ocean

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IEEE JOURNAL OF SELECTED TOPICS IN APPLIED EARTH OBSERVATIONS AND REMOTE SENSING 2017年第9期10卷 3963-3974页

作者： Duncan, David Ian Kummerow, Christian D. Meier, Walter N. Colorado State Univ Dept Atmospher Sci Ft Collins CO 80523 USA NASA Goddard Space Flight Ctr Cryospher Sci Lab Greenbelt MD 20771 USA

Integrated processing and analysis are presented for oceanic retrievals of precipitation, sea ice concentration, columnar water vapor and cloud water, sea surface temperature, and near-surface wind from the advanced microwave scanning radiometer-2 (AMSR2) sensor. By developing a common algorithmic framework and permitting iterative interaction between historically separate science algorithms, ambiguous and contradictory retrieval results are minimized. The integration also serves to improve each algorithm individually, decreasing reliance on ancillary datasets. Case studies are presented that exemplify both ongoing challenges for these retrievals and potential research uses of such an integrated satellite product. Two cases are presented each for precipitation at high latitudes and marginal sea ice detection, with analysis supplemented by satellite data from CloudSat profiles and Himawari-8 imagery. Detection and retrieval of snowfall remains a challenge, while light rainfall detection can be aided by a variational algorithm. Sea ice concentrations below 20% cause disagreements, but the algorithms otherwise agree well on the sea ice edge. Potential mitigation strategies for ambiguous areas of light rainfall and marginal sea ice are discussed. The analysis demonstrates potential avenues for future algorithm development, but also some physical limitations of remote sensing with the AMSR2 frequencies.

关键词： Passive microwave remote sensing precipitation retrieval algorithms sea ice variational methods

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Polarimetric remote sensing of atmospheric aerosols: Instruments, methodologies, results, and perspectives

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JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER 2019年 224卷 474-511页

作者： Dubovik, Oleg Li, Zhengqiang Mishchenko, Michael I. Tanre, Didier Karol, Yana Bojkov, Bojan Cairns, Brian Diner, David J. Espinosa, W. Reed Goloub, Philippe Gu, Xingfa Hasekamp, Otto Hong, Jin Hou, Weizhen Knobelspiesse, Kirk D. Landgraf, Jochen Li, Li Litvinov, Pavel Liu, Yi Lopatin, Anton Marbach, Thierry Maring, Hal Martins, Vanderlei Meijer, Yasjka Milinevsky, Gennadi Mukai, Sonoyo Parol, Frederic Qiao, Yanli Remer, Lorraine Rietjens, Jeroen Sano, Itaru Stammes, Piet Stamnes, Snorre Sun, Xiaobing Tabary, Pierre Travis, Larry D. Waquet, Fabien Xu, Feng Yan, Changxiang Yin, Dekui Univ Lille Lab Opt Atmospher CNRS Villeneuve Dascq France Chinese Acad Sci State Environm Protect Key Lab Satellite Remote S Inst Remote Sensing & Digital Earth Beijing Peoples R China NASA Goddard Inst Space Studies New York NY 10025 USA GRASP SAS Villeneuve Dascq France European Org Exploitat Meteorol Satellites EUMETS Darmstadt Germany CALTECH Jet Prop Lab Pasadena CA USA Univ Maryland Baltimore Cty Baltimore MD 21228 USA NASA Goddard Space Flight Ctr Greenbelt MD USA SRON Netherlands Inst Space Res Utrecht Netherlands Chinese Acad Sci Anhui Inst Opt & Fine Mech Hefei Anhui Peoples R China Chinese Acad Sci Inst Atmospher Phys Beijing Peoples R China NASA Headquarters Div Earth Sci Sci Mission Directorate Washington DC USA ESA Keplerlaan 1 NL-2201 AZ Noordwijk Netherlands Taras Shevchenko Natl Univ Kyiv Kiev Ukraine Kyoto Coll Grad Studies Informat Kyoto Japan Kindai Univ Fac Sci & Engn Osaka Japan Royal Netherlands Meteorol Inst De Bilt Netherlands NASA Langley Res Ctr Hampton VA 23665 USA CNES Direct Innovat Applicat & Sci DIA Toulouse France Chinese Acad Sci Changchun Inst Opt Fine Mech & Phys Changchun Jilin Peoples R China Chinese Acad Sci Shanghai Inst Tech Phys Shanghai Peoples R China

Polarimetry is one of the most promising types of remote sensing for improved characterization of atmospheric aerosol. Indeed, aerosol particles constitute a highly variable atmospheric component characterized by a large number of parameters describing particle sizes, morphologies (including shape and internal structure), absorption and scattering properties, amounts, horizontal and vertical distribution, etc. Reliable monitoring of all these parameters is very challenging, and therefore the aerosol effects on climate and environment are considered to be among the most uncertain factors in climate and environmental research. In this regard, observations that provide both the angular distribution of the scattered atmospheric radiation as well as its polarization state at multiple wavelengths covering the UV-SWIR spectral range carry substantial implicit information on the atmospheric composition. Therefore, high expectations in improving aerosol characterization are associated with detailed passive photopolarimetric observations. The critical need to use space-borne polarimetry for global accurate monitoring of detailed aerosol properties was first articulated in the late 1980s and early 1990s. By now, several orbital instruments have already provided polarization observations from space, and a number of advanced missions are scheduled for launch in the coming years by international and national space agencies. The first and most extensive record of polarimetric imagery was provided by POLDER-I, POLDER-II, and POLDER/PARASOL multi-angle multi-spectral polarization sensors. Polarimetric observations with the POLDER-like design intended for collecting extensive multi-angular multi-spectral measurements will be provided by several instruments, such as the MAI/TG-2, CAPI/TanSat, and DPC/GF-5 sensors recently launched by the Chinese Space Agency. Instruments such as the 3MI/MetOp-SG, MAIA, SpexOne and HARP2 on PACE, POSP, SMAC, PCF, DPC-Lidar, ScanPol and MSIP/Aerosol-UA,

关键词： Aerosols Remote sensing Polarimetry Radiative transfer retrieval algorithms

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Linearized vector radiative transfer model MCC plus plus for a spherical atmosphere

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JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER 2004年第1-3期88卷 297-317页

作者： Postylyakov, OV Russian Acad Sci AM Obukhov Inst Atmospher Phys Moscow 119017 Russia Finnish Meteorol Inst FIN-00101 Helsinki Finland

Application of radiative transfer models has shown that optical remote sensing requires extra characteristics of radiance field in addition to the radiance intensity itself. Simulation of spectral measurements, analysis of retrieval errors and development of retrieval algorithms are in need of derivatives of radiance with respect to atmospheric constituents under investigation. The presented vector spherical radiative transfer model MCC++ was linearized, which allows the calculation of derivatives of all elements of the Stokes vector with respect to the volume absorption coefficient simultaneously with radiance calculation. The model MCC++ employs Monte Carlo algorithm for radiative transfer simulation and takes into account aerosol and molecular scattering, gas and aerosol absorption, and Lambertian surface albedo. The model treats a spherically symmetrical atmosphere. Relation of the estimated derivatives with other forms of radiance derivatives: the weighting functions used in gas retrieval and the air mass factors used in the DOAS retrieval algorithms, is obtained. Validation of the model against other radiative models is over-viewed. The computing time of the intensity for the MCC++ model is about that for radiative models treating sphericity of the atmosphere approximately and is significantly shorter than that for the full spherical models used in the comparisons. The simultaneous calculation of all derivatives (i.e. with respect to absorption in all model atmosphere layers) and the intensity is only 1.2-2 times longer than the calculation of the intensity only. (C) 2004 Elsevier Ltd. All rights reserved.

关键词： radiative transfer polarization derivatives weighting functions air mass factors remote sensing inverse problems retrieval algorithms

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Validation of MODIS ocean-colour products in the coastal waters of the Yellow Sea and East China Sea

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Acta Oceanologica Sinica 2020年第1期39卷 91-101页

作者： Lingling Jiang Xiangyu Guo Lin Wang Shubha Sathyendranath Hayley Evers-King Yanlong Chen Bingnan Li College of Environmental Science and Engineering Dalian Maritime UniversityDalian 116026China Ministry of Ecology Environment National Marine Environmental Monitoring CenterDalian 116023China Plymouth Marine Laboratory(PML) PlymouthDevonPL13DHUK

An extensive study collected in situ data along the Yellow Sea(YS) and East China Sea(ECS) to assess the radiometric properties and the concentration of the water constituents derived from Moderate Resolution Imaging Spectroradiometer(MODIS). Thirteen high quality match-ups were obtained for evaluating the MODIS estimates of Rrs(λ), chlorophyll a(Chl a) and concentrations of suspended particulate sediment matter(SPM). For MODIS Rrs(λ), the mean absolute percentage difference(APD) was in the range of 20%–36%, and the highest uncertainty appeared at 412 nm, whereas the band ratio of Rrs(λ) at 488 nm compared with that at 547 nm was highly consistent, with an APD of 7%. A combination of near-infrared bands and shortwave infrared wavelengths atmosphere correction algorithm(NIR-SWIR algorithm) was applied to the MODIS data, and the estimation accuracy of Rrs were improved at most of the visible spectral bands except 645 nm, 667 nm and 678 nm. Two ocean-colour empirical algorithms for Chl a estimation were applied to the processed data, the results indicated that the accuracy of the derived Chl a values was obviously improved, the four-band algorithms outperformed the other algorithm for measured and simulated datasets, and the minimum APD was 35%. The SPM was also quantified. Two regional and two coastal SPM algorithms were modified according to the in situ data. By comparison, the modified Tassan model had a higher accuracy for the application along the YS and ECS with an APD of 21%. However, given the limited match-up dataset and the potential influence of the aerosol properties on atmosphere correction, further research is required to develop additional algorithms especially for the low Chl a coastal water.

关键词： MODIS turbid waters chlorophyll a SPM retrieval algorithms Yellow and East China Sea

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Observations of the ozone and nitrogen dioxide profiles in the TROICA-4 experiment

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ATMOSPHERIC REMOTE SENSING: EARTH'S SURFACE, TROPOSPHERE, STRATOSPHERE AND MESOSPHERE - II 2006年第12期37卷 2231-2237页

作者： Postylyakov, O. V. Belikov, I. B. Elansky, N. F. Elokhov, A. S. RAS LAGS AM Obukhov Inst Atmospher Phys Moscow 119017 Russia

To investigate the vast area of Russia, a mobile scientific facility based in a railway carriage was developed. It is capable to perform continues measurements being coupled in a passenger train traveling along railroads. It was first equipped with a spectrometer for remote sensing of ozone and nitrogen dioxide in the atmosphere for the transcontinental observations into the chemistry of the atmosphere-4 expedition performed from February 18 to March 5, 1998. A twilight DOAS method, which was applied for retrieval of the nitrogen dioxide profiles basing on spectral measurements at the visible wavelengths (434-451 nm), is described in the paper. Main features of a new algorithm for retrieval of the ozone profile and total content using the differential structure of the UV spectrum (310-335 nm) are presented. The ozone and nitrogen dioxide contents are obtained and shortly validated against available alternative data. (c) 2006 Published by Elsevier Ltd on behalf of COSPAR.

关键词： ozone nitrogen dioxide vertical distribution total content radiative transfer model retrieval algorithms DOAS technique air mass factors

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An empirical line-by-line model for the infrared solar transmittance spectrum from 700 to 5000 cm^-1

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JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER 2006年第3期102卷 450-463页

作者： Hase, F. Demoulin, P. Sauval, A. J. Toon, G. C. Bernath, P. F. Goldman, A. Hannigan, J. W. Rinsland, C. P. Forschungszentrum Karlsruhe Inst Meteorol & Klimaforsch D-76021 Karlsruhe Germany Inst Astrophys & Geophys B-4000 Liege Belgium Observ Royal Belgique B-1180 Brussels Belgium Jet Propuls Lab Pasadena CA 91109 USA Univ Waterloo Dept Chem Waterloo ON N2L 3G1 Canada Univ Denver Dept Phys Denver CO 80208 USA Natl Ctr Atmospher Res Div Atmospher Chem Boulder CO 80303 USA NASA Langley Res Ctr Hampton VA 23681 USA

An empirical line-by-line model for the infrared solar transmittance spectrum is presented. The model can be incorporated into radiative transfer codes to allow fast calculation of all relevant emission and absorption features in the solar spectrum in the mid-infrared region from 700 to 5000 cm(-1). The transmittance is modelled as a function of the diameter of the field-of-view centered on the solar disk: the line broadening due to solar rotation as well as center-to-limb variations in strength and width are taken into account for stronger lines. Applications of the model presented here are in the fields of terrestrial remote sensing in the mid-infrared spectral region when the sun is used as radiation source or scattered solar radiation contributes to the measured signal and in the fields of atmospheric radiative transfer algorithms which compute the propagation of infrared solar radiation in the terrestrial atmosphere. (c) 2006 Elsevier Ltd. All rights reserved.

关键词： infrared spectroscopy atmospheric trace gases solar spectrum radiative transfer retrieval algorithms

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Beamfilling errors in passive microwave rainfall retrievals

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JOURNAL OF APPLIED METEOROLOGY 1998年第4期37卷 356-370页

作者： Kummerow, C NASA Goddard Space Flight Ctr Atmospheres Lab Greenbelt MD 20771 USA

There are currently large numbers of rainfall retrieval algorithms based upon passive microwave radiances. Most of these algorithms are physically based in that they use explicit physical assumptions to derive relationships between brightness temperatures (Tb's) and rainfall. If these assumptions involve observable quantities, then the physical basis of the algorithms can be extended to determine fundamental uncertainties in the retrieved precipitation fields. In this paper this process begins by examining the largest uncertainty in many of the physical models-the homogenous rainfall assumption. Four months of Tropical Oceans Global Atmosphere Coupled Ocean-Atmosphere Response Experiment shipborne radar data is used to describe the horizontal characteristics of win. The vertical hydrometeor structures needed to simulate the upwelling Tb are taken from a dynamic al cloud model. Radiative transfer computations were performed using a fully three-dimensional Monte Carlo solution in order to test all aspects of the beamfilling problem. Results show that biases as well as random errors depend upon the assumed vertical structure of hydrometeors, the manner in which inhomogeneity is modeled in the retrieval, and the manner in which the radiative transfer problem is handled. Unlike previous works. the goal of this paper is not to determine a mean beamfilling correction or a vertical hydrometeor profile that should be applied to specific retrieval algorithms. Rather, it is to explore the impact of inhomogeneous rainfall upon the predicted brightness temperatures so that these relations may eventually be used to develop a physically based error model for microwave precipitation retrievals. Because the predicted Tb's depend upon assumed cloud vertical structures, the paper offers a procedure to account for the uncertainty introduced by rainfall inhomogeneity rather than a general result. The impact of inhomogeneous rainfall upon specific algorithms must still be investigated wi

关键词： .Rainfall Monte Carlo explicit homogeneous radar data beam Biases Cloud Model retrieval algorithms Retrieved lling inhomogeneity Passive Microwave hydrometeor transfer computations

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Estimate of boundary-layer depth in Nanjing city using aerosol lidar data during 2016-2017 winter

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ATMOSPHERIC ENVIRONMENT 2019年 205卷 67-77页

作者： Fan, Sihui Gao, Zhiqiu Kalogiros, John Li, Yubin Yin, Jian Li, Xin Nanjing Univ Informat Sci & Technol Climate & Weather Disasters Collaborat Innovat Ct Sch Atmospher Phys Key Lab Aerosol Cloud PrecipitatChina Meteorol A Nanjing 210044 Jiangsu Peoples R China Chinese Acad Sci Inst Atmospher Phys State Key Lab Atmospher Boundary Layer Phys & Atm Beijing 100029 Peoples R China Natl Observ Athens Inst Environm Res & Sustainable Dev Athens 11810 Greece

The planetary boundary-layer (PBL) structure was investigated using observations from single aerosol lidar, eddy covariance (EC) system, and automatic meteorological station (AWS) in the north of Nanjing city during an air pollution episode in 2016-2017 winter. Based on seven days' observations under clear to polluted day, we present the temporal variations of the aerosol extinction profiles observed by lidar, and then inter-compare PBL depth retrieved from individual gradient methods. The results show that the gradient method (GM) generated the lowest PBL depth. In contrast to the cubic root gradient method (CRGM), which determined PBL depth ranging from 172 m to 1575 m during the observation period, the logarithm gradient method (LGM) and normalized gradient method (NGM) generated similar results and both tended to overestimate PBL depth on polluted days. The CRGM performed better than LGM and NGM in case of multiple backscatter layers and could detect low level layers, while the GM was biased at low heights probably due to the effect of lidar overlap function. Based on these measurements, the evolution of boundary layer structures and PBL depth over clean days and polluted days were compared. The results show that (1) on clean days, the strong surface turbulence exchange make the PBL depth fully developed and the PBL depth had obvious characteristics of diurnal variation;the maximum depth of PBL was 1560 m for CRGM;and (2) on polluted days, the high pressure system and lower wind was favorable to the accumulation of air pollutants, and thus generating less turbulence by reducing surface radiation. These conditions on polluted days led to smaller PBL depth than those on clean days, and the maximum depth of PBL was 660 m for CRGM. Besides, the diurnal variation of PBL depth on polluted days was weaker than those on clean days.

关键词： Inter-comparison PBL depth Lidar retrieval algorithms Air pollution

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Long-term variation of phytoplankton biomass and physiology in Taihu lake as observed via MODIS satellite

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WATER RESEARCH 2019年 153卷 187-199页

作者： Huang, Changchun Zhang, Yunlin Huang, Tao Yang, Hao Li, Yunmei Zhang, Zhigang He, Mengying Hu, Zhujun Song, Ting Zhu, A-xing Nanjing Normal Univ Jiangsu Ctr Collaborat Innovat Geog Informat Reso Nanjing 210023 Jiangsu Peoples R China Nanjing Normal Univ Minist Educ Key Lab Virtual Geog Environm Nanjing 210023 Jiangsu Peoples R China Nanjing Normal Univ Sch Geog Sci Nanjing 210023 Jiangsu Peoples R China Chinese Acad Sci Nanjing Inst Geog & Limnol State Key Lab Lake Sci & Environm Nanjing 210008 Jiangsu Peoples R China Environm Monitoring Ctr Wuxi 214000 Peoples R China Univ Wisconsin Dept Geog Madison WI 53706 USA

Estimation of phytoplankton biomass (noted as phytoplankton carbon, C-phyto) and evaluation of phytoplankton physiology is central to the estimation of primary productivity and the carbon cycle. This issue has been widely considered in oceans but not in inland water. Here, we develop experiential and semi analytical models, which validated by independent in situ measurement data, respectively, to derive C-phyto and phytoplankton absorption coefficient at 675 nm (a(ph)(675)) from MODIS. The effects of nutrients and temperature on the seasonal variation of phytoplankton physiology were assessed through a novel proxy of C-phyto to a(ph)(675) ratio (C-phyto/a(ph)(675)) over the Lake Taihu, the third largest lake in China. Significant seasonal climatological cycles of C-phyto, a(ph)(675) and C-phyto/a(ph)(675) were observed in Lake Taihu, especially in Meiliang Bay and Zhushan Bay, where algal blooms occur frequently. The highest C-phyto and a(ph)(675) values were observed in summer due to the growth of phytoplankton biomass and chlorophyll-a concentration. Lower values were observed in winter and spring, which are characterized by relatively high total nitrogen levels and low irradiance, owing to the low temperature astricts the algae growth. However, the C-phyto/a(ph)(675) shows an opposite trend compared to C-phyto and a(ph)(675), which have high values in winter and low values in summer. The analysis of C-phyto, a(ph)(675) and C-phyto/aph(675) with total phosphorus (TP) levels and temperature indicates that TP are the main positive driver of the increase in C-phyto and a(ph)(675) and negatively regulate C-phyto/a(ph)(675). Warming promotes an increase in C-phyto and a(ph)(675) and restricts C-phyto/a(ph)(675) in summer. Biomass and nutrient levels are the primary drivers of the decrease of C-phyto/a(ph)(675) in such a typical eutrophic lake. The results present some new findings compared to previous oceanic studies and expand our knowledge in the study of phytoplankt

关键词： Eutrophic lake Phytoplankton absorption coefficient Satellite data retrieval algorithms

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