Radiative forcing as an index of climate change can reflect the relative effect of climate factors. To understand climatic implications of aerosols over the China Seas, the aerosol direct radiative forcing at the top of atmosphere (TOA) is computed using three-year collocated Clouds and the Earth's Radiant Energy System (CERES) radiation fluxes and Moderate Resolution Imaging Spectroradiometer (MODIS) aerosol optical thickness data on the platform Terra. The upward radiation flux for clear skies is a key for the aerosol radiative forcing at the TOA. A linear relationship is found between the solar radiation fluxes at the TOA from CERES and the aerosol optical thickness is at 550 nm from MODIS over the China Seas. In a linear regression Eq., the intercept for zero aerosol optical thickness is the radiation flux at the TOA for clear skies. Based on the definition of the aerosol direct radiative forcing at TOA and the diurnal correction factor from a simulated radiative forcing using radiation transfer model, the daily averaged aerosol direct radiative forcing at the TOA is estimated and its seasonal variations over the cloud-free China Seas are presented. In total, the aerosol radiative forcing over the China Seas is negative. It implies that the aerosol over the China Seas is mainly a cooling effect on climate change, which is opposite to the greenhouse effect. The largest aerosol radiative forcing is found in spring, while the smallest is in summer. The aerosol radiative forcing over the coastal region is always more than that in the open ocean in four seasons. The method in the study can be used for evaluation of the aerosols impact on global or region climate from satellite measurements.
{"title":"Aerosol direct radiative forcing at the top of atmosphere based on satellite remote sensing over China Seas: a preliminary study","authors":"Zengzhou Hao, D. Pan, Fang Gong","doi":"10.1117/12.910433","DOIUrl":"https://doi.org/10.1117/12.910433","url":null,"abstract":"Radiative forcing as an index of climate change can reflect the relative effect of climate factors. To understand climatic implications of aerosols over the China Seas, the aerosol direct radiative forcing at the top of atmosphere (TOA) is computed using three-year collocated Clouds and the Earth's Radiant Energy System (CERES) radiation fluxes and Moderate Resolution Imaging Spectroradiometer (MODIS) aerosol optical thickness data on the platform Terra. The upward radiation flux for clear skies is a key for the aerosol radiative forcing at the TOA. A linear relationship is found between the solar radiation fluxes at the TOA from CERES and the aerosol optical thickness is at 550 nm from MODIS over the China Seas. In a linear regression Eq., the intercept for zero aerosol optical thickness is the radiation flux at the TOA for clear skies. Based on the definition of the aerosol direct radiative forcing at TOA and the diurnal correction factor from a simulated radiative forcing using radiation transfer model, the daily averaged aerosol direct radiative forcing at the TOA is estimated and its seasonal variations over the cloud-free China Seas are presented. In total, the aerosol radiative forcing over the China Seas is negative. It implies that the aerosol over the China Seas is mainly a cooling effect on climate change, which is opposite to the greenhouse effect. The largest aerosol radiative forcing is found in spring, while the smallest is in summer. The aerosol radiative forcing over the coastal region is always more than that in the open ocean in four seasons. The method in the study can be used for evaluation of the aerosols impact on global or region climate from satellite measurements.","PeriodicalId":340728,"journal":{"name":"China Symposium on Remote Sensing","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129439565","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Daming Wang, Fang Hou, Zhizhong Li, Fuxing Dang, Rihong Yang, Z. J. Xiao
This paper focuses on the analysis and selection of space-borne hyperspectral sensor parameters, through the simulation of the entire data acquisition process and the applications using simulated hyperspectral data. Aiming at the alteration mineral identification and mapping, we used the simulated space-borne hyperspectral data with different payload parameters including the spatial resolution, spectral resolution and Signal-to-Noise-Rate (SNR) from HyMAP air-borne hyperspectral data in Dongtianshan area in Xinjiang Province of China to identify and map the alteration minerals, so that we could analyze and compare these results to find the optimal combination of payload parameters. A combination of the parameters of 30m spatial resolution, 10 - 20nm spectral resolution and 200:1 (VNIR) / 150:1 (SWIR) SNR was evaluated to possess the strongest ability for the mineral identification and mapping. This technology can also be promoted by the other payload parameter analysis and selection.
{"title":"The analysis on parameters of the payload on hyperspectral satellite","authors":"Daming Wang, Fang Hou, Zhizhong Li, Fuxing Dang, Rihong Yang, Z. J. Xiao","doi":"10.1117/12.910365","DOIUrl":"https://doi.org/10.1117/12.910365","url":null,"abstract":"This paper focuses on the analysis and selection of space-borne hyperspectral sensor parameters, through the simulation of the entire data acquisition process and the applications using simulated hyperspectral data. Aiming at the alteration mineral identification and mapping, we used the simulated space-borne hyperspectral data with different payload parameters including the spatial resolution, spectral resolution and Signal-to-Noise-Rate (SNR) from HyMAP air-borne hyperspectral data in Dongtianshan area in Xinjiang Province of China to identify and map the alteration minerals, so that we could analyze and compare these results to find the optimal combination of payload parameters. A combination of the parameters of 30m spatial resolution, 10 - 20nm spectral resolution and 200:1 (VNIR) / 150:1 (SWIR) SNR was evaluated to possess the strongest ability for the mineral identification and mapping. This technology can also be promoted by the other payload parameter analysis and selection.","PeriodicalId":340728,"journal":{"name":"China Symposium on Remote Sensing","volume":"71 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126357549","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Searching for a seamline kept away from area with great differece between overlapping orthoimages is significant for orthoimage mosaic, which is an important step in Digital Orthoimage Map(DOM) production.A method combine Minimizing Local Maximum Algotirhm and Greedy Select Algorithm for seamline searching is introduced. In process of searching, maximum differece along the seam-line is limited. Results show that this method is self-adaptable and is able to accomplish high quality seam-line searching.
{"title":"Orthoimage seamline searching based on minimizing local maximum algorithm","authors":"Can Zhong, Yiliu Yang","doi":"10.1117/12.910394","DOIUrl":"https://doi.org/10.1117/12.910394","url":null,"abstract":"Searching for a seamline kept away from area with great differece between overlapping orthoimages is significant for orthoimage mosaic, which is an important step in Digital Orthoimage Map(DOM) production.A method combine Minimizing Local Maximum Algotirhm and Greedy Select Algorithm for seamline searching is introduced. In process of searching, maximum differece along the seam-line is limited. Results show that this method is self-adaptable and is able to accomplish high quality seam-line searching.","PeriodicalId":340728,"journal":{"name":"China Symposium on Remote Sensing","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133965083","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Based on ATOVS data and conventional sounding data, two assimilation experiments are performed to simulate a heavy rainfall over the middle-lower reaches of Yangtze River and the east of southwest China from June 22 to 24 in 2004 by using model MM5. In the NOATOVS experiment, only conventional sounding data are assimilated based on the successive correction scheme, while in the ATOVS experiment, the ATOVS radiance data are assimilated by using the GRAPES (Global and Regional Assimilation and Prediction System) 3D-Var system. The effect of the radiance data on the background field is analyzed. It indicates that direct assimilation of ATOVS radiance data could improve the temperature, humidity and wind fields within the troposphere. Moreover, the comparison between the results of the two experiments shows that ATOVS experiment can not only simulate the circulation pattern well, but also describe the intensity and the distribution of the rainfall better than the NOATOVS experiment.
基于ATOVS资料和常规探测资料，利用MM5模式对2004年6月22 ~ 24日长江中下游及西南东部地区的一次强降水进行了同化试验。在NOATOVS实验中，仅基于逐次校正方案同化常规探测数据，而在ATOVS实验中，使用GRAPES (Global and Regional Assimilation and Prediction System) 3D-Var系统同化ATOVS辐射数据。分析了辐射度数据对背景场的影响。结果表明，直接同化ATOVS辐射数据可以改善对流层内的温度、湿度和风场。两种试验结果的对比表明，ATOVS试验不仅能较好地模拟环流型，而且能较好地描述降水的强度和分布。
{"title":"Application of ATOVS radiance assimilation to numerical simulation of a mesoscale heavy rainfall","authors":"H. Bing, Bai Jie, Li Wei, Xiaoting Wang","doi":"10.1117/12.910435","DOIUrl":"https://doi.org/10.1117/12.910435","url":null,"abstract":"Based on ATOVS data and conventional sounding data, two assimilation experiments are performed to simulate a heavy rainfall over the middle-lower reaches of Yangtze River and the east of southwest China from June 22 to 24 in 2004 by using model MM5. In the NOATOVS experiment, only conventional sounding data are assimilated based on the successive correction scheme, while in the ATOVS experiment, the ATOVS radiance data are assimilated by using the GRAPES (Global and Regional Assimilation and Prediction System) 3D-Var system. The effect of the radiance data on the background field is analyzed. It indicates that direct assimilation of ATOVS radiance data could improve the temperature, humidity and wind fields within the troposphere. Moreover, the comparison between the results of the two experiments shows that ATOVS experiment can not only simulate the circulation pattern well, but also describe the intensity and the distribution of the rainfall better than the NOATOVS experiment.","PeriodicalId":340728,"journal":{"name":"China Symposium on Remote Sensing","volume":"123 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116620830","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The Lop Nur region is located in the east of the Tarim Basin. It has served as the strategic passage and communication hub of the Silk Road since Han Dynasty. During Wei-Jin period, the river system there was well developed and the ancient city of Loulan was bred there. In this study, GIS is used to accomplish automatic extraction of the river course in the Lop Nur region at first using ArcGIS. Then the RCI index is constituted to extract ancient river course from Landsat ETM image with band 3 and band 4. It is concluded that the north river course of Peacock River conformed before the end of the 4th century AD according to the distribution of the entire river course of the Lop Nur region. Later, the Peacock River changed its way to south to Tarim River, and flowed into Lop Nur along the direction paralleling Altun Mountain from west to east. It was the change of the river system that mainly caused the decrease in water supply around ancient city of Loulan before the end of 4th century. The ancient city of Loulan has been gradually ruined in the sand because of the absence of water supply since then.
{"title":"Analysis of the ancient river system in Loulan period in Lop Nur region","authors":"Jianfeng Zhu, Peng Jia, Yueping Nie","doi":"10.1117/12.910420","DOIUrl":"https://doi.org/10.1117/12.910420","url":null,"abstract":"The Lop Nur region is located in the east of the Tarim Basin. It has served as the strategic passage and communication hub of the Silk Road since Han Dynasty. During Wei-Jin period, the river system there was well developed and the ancient city of Loulan was bred there. In this study, GIS is used to accomplish automatic extraction of the river course in the Lop Nur region at first using ArcGIS. Then the RCI index is constituted to extract ancient river course from Landsat ETM image with band 3 and band 4. It is concluded that the north river course of Peacock River conformed before the end of the 4th century AD according to the distribution of the entire river course of the Lop Nur region. Later, the Peacock River changed its way to south to Tarim River, and flowed into Lop Nur along the direction paralleling Altun Mountain from west to east. It was the change of the river system that mainly caused the decrease in water supply around ancient city of Loulan before the end of 4th century. The ancient city of Loulan has been gradually ruined in the sand because of the absence of water supply since then.","PeriodicalId":340728,"journal":{"name":"China Symposium on Remote Sensing","volume":"75 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127079059","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Space-borne hyperspectral remote sensing imagery, supplying both spatial and spectral information for quantitative remote sensing monitoring, is easily polluted by noises from atmosphere, terrain etc. Based on spectral continuum removing and recovering, traditional fast Fourier Transform (FFT) was extended to Continuum Fast Fourier Transform (CFFT) to separate noise from target information in frequency domain (FD). Thus, low-pass filter for reserving useful information was designed for eliminating noise, with its cut-off frequency selected self-adaptively by optimal signal-tonoise ratio (SNR). Hyperion hyperspectral imageries of Beijing and Xinjiang China were singled out for noise removing to validate the filtering ability of the Continuum Fast Fourier Transform self-adapted by Optimal Signal-noise Ratio(CFFTOSNR) method with qualitative description and quantificational indexs, including mean, variance, entropy, definition and SNR etc. Experiment result shows that CFFTOSNR does well in reducing the gauss white noises in spectral domain and stripe and band-subtracting noise in spatial domain respectively, while the quantificational indexs of filtered imagery are all improved, with entropy of post-processed image obviously increased by 5 db.
{"title":"Space-borne hyperspectral remote sensing imagery noise eliminating based on CFFT self-adapted by optimal SNR","authors":"Qingjie Liu, Qizhong Lin, Liming Wang, Qinjun Wang, Fengxian Miao","doi":"10.1117/12.910400","DOIUrl":"https://doi.org/10.1117/12.910400","url":null,"abstract":"Space-borne hyperspectral remote sensing imagery, supplying both spatial and spectral information for quantitative remote sensing monitoring, is easily polluted by noises from atmosphere, terrain etc. Based on spectral continuum removing and recovering, traditional fast Fourier Transform (FFT) was extended to Continuum Fast Fourier Transform (CFFT) to separate noise from target information in frequency domain (FD). Thus, low-pass filter for reserving useful information was designed for eliminating noise, with its cut-off frequency selected self-adaptively by optimal signal-tonoise ratio (SNR). Hyperion hyperspectral imageries of Beijing and Xinjiang China were singled out for noise removing to validate the filtering ability of the Continuum Fast Fourier Transform self-adapted by Optimal Signal-noise Ratio(CFFTOSNR) method with qualitative description and quantificational indexs, including mean, variance, entropy, definition and SNR etc. Experiment result shows that CFFTOSNR does well in reducing the gauss white noises in spectral domain and stripe and band-subtracting noise in spatial domain respectively, while the quantificational indexs of filtered imagery are all improved, with entropy of post-processed image obviously increased by 5 db.","PeriodicalId":340728,"journal":{"name":"China Symposium on Remote Sensing","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129444301","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
L. Mei, Yong Xue, J. Guang, Yingjie Li, Ying Wang, Hui Xu, Xingwei He, Shuzheng Jiang, Xijuan Jiao, Ziqiang Chen, Jianwen Ai
The accuracy of aerosol optical depth (AOD) products from polar-orbit satellites such as FengYun-3A (FY3A) is limited, especially over land because it is hard to discriminate the contribution of the observed signal reflected by the surface from the one scattered and absorbed by the aerosols over bright surface. In this paper, an approach by exploiting the synergy of FengYun-3A (FY-3A) and Moderate Resolution Imaging Spectroradiometer (MODIS) data were presented. The derived AOD compared to Aerosol Robotic Network (AERONET) observation and retrieval absolute error around 0.1 is found, with R2 of 0.77. Moreover, a dust episode was presented in Mongolia on late March, 2010.; By using HYbrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) mode as well as the meteorological parameters, we analyzed the advection and dispersion of this event, its transport effect for the episode and its influence. Our data demonstrated that AOD increased up to 2.0 during the burning phase and then returned to normal values (0.2- 0.5), and the aerosol properties various, including both the AOD and aerosol type or source, which has a vertical distribution difference, fully in line with transport process. This method should be wildly used on FY series satellite.
{"title":"Aerosol optical depth retrieval over land using FY-3A data and its application in dust monitoring","authors":"L. Mei, Yong Xue, J. Guang, Yingjie Li, Ying Wang, Hui Xu, Xingwei He, Shuzheng Jiang, Xijuan Jiao, Ziqiang Chen, Jianwen Ai","doi":"10.1117/12.910398","DOIUrl":"https://doi.org/10.1117/12.910398","url":null,"abstract":"The accuracy of aerosol optical depth (AOD) products from polar-orbit satellites such as FengYun-3A (FY3A) is limited, especially over land because it is hard to discriminate the contribution of the observed signal reflected by the surface from the one scattered and absorbed by the aerosols over bright surface. In this paper, an approach by exploiting the synergy of FengYun-3A (FY-3A) and Moderate Resolution Imaging Spectroradiometer (MODIS) data were presented. The derived AOD compared to Aerosol Robotic Network (AERONET) observation and retrieval absolute error around 0.1 is found, with R2 of 0.77. Moreover, a dust episode was presented in Mongolia on late March, 2010.; By using HYbrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) mode as well as the meteorological parameters, we analyzed the advection and dispersion of this event, its transport effect for the episode and its influence. Our data demonstrated that AOD increased up to 2.0 during the burning phase and then returned to normal values (0.2- 0.5), and the aerosol properties various, including both the AOD and aerosol type or source, which has a vertical distribution difference, fully in line with transport process. This method should be wildly used on FY series satellite.","PeriodicalId":340728,"journal":{"name":"China Symposium on Remote Sensing","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127785679","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Xiaodong Ding, Bin Zhou, Junfeng Xu, Ting Liu, Bin Xie
The surplus of phosphorus leads to water eutrophication. Huge input of fertilizers in agricultural activities enriches nutrition in soil. The superfluous nutrient moves easily to riparian water by rainfall and surface runoff; leads to water eutrophication of riparian wetlands and downstream water; and consequently affects ecological balance. Thus it is significant to investigate the risk of phosphorus loss in agricultural land, to identify high concentration areas and guide the management of nutrition loss. This study was implemented mainly in the area of agricultural use in southern Western Australia, where a three-year period preliminary monitoring of water quality showed that the concentration of different forms of phosphorus in water had far exceeded the standard. Due to the large scale surface runoff caused by occasional storms in Western Australia, soil erosion was selected as the main driving factor for the loss of phosphorus. Remote sensing and ground truth data were used to reflect the seasonal changes of plants. The spatial distribution of available phosphorus was then predicted and combined with the evaluation matrix to evaluate the loss risk of phosphorus. This evaluation was based on quantitative rather than qualitative data to make better precision. It could help making decision support for monitoring water quality of rivers and riparian wetlands.
{"title":"Risk evaluation of available phosphorus loss in agricultural land based on remote sensing and GIS","authors":"Xiaodong Ding, Bin Zhou, Junfeng Xu, Ting Liu, Bin Xie","doi":"10.1117/12.910428","DOIUrl":"https://doi.org/10.1117/12.910428","url":null,"abstract":"The surplus of phosphorus leads to water eutrophication. Huge input of fertilizers in agricultural activities enriches nutrition in soil. The superfluous nutrient moves easily to riparian water by rainfall and surface runoff; leads to water eutrophication of riparian wetlands and downstream water; and consequently affects ecological balance. Thus it is significant to investigate the risk of phosphorus loss in agricultural land, to identify high concentration areas and guide the management of nutrition loss. This study was implemented mainly in the area of agricultural use in southern Western Australia, where a three-year period preliminary monitoring of water quality showed that the concentration of different forms of phosphorus in water had far exceeded the standard. Due to the large scale surface runoff caused by occasional storms in Western Australia, soil erosion was selected as the main driving factor for the loss of phosphorus. Remote sensing and ground truth data were used to reflect the seasonal changes of plants. The spatial distribution of available phosphorus was then predicted and combined with the evaluation matrix to evaluate the loss risk of phosphorus. This evaluation was based on quantitative rather than qualitative data to make better precision. It could help making decision support for monitoring water quality of rivers and riparian wetlands.","PeriodicalId":340728,"journal":{"name":"China Symposium on Remote Sensing","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117326798","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this study, the optical depth of vegetation is worked out with Microwave Polarization Difference Index (MPDI) focusing on the drought that hit Yunnan in early 2010 and using AMSR-E data of the first three months of 2010 in Yunnan Province. Inversion of soil moisture is conducted by using Microwave radiative transfer model and Dielectric constant model, and thereupon drought grading is made, so that the drought grades of the first three months of 2010 in most of the regions in Yunnan Province are obtained. By verifying the retrieval results by means of the soil moisture data collected from ground-based measurements, the conclusion of this study is drawn: with the research method by which soil moisture is retrieved from AMSR-E data, and thereupon the drought grading is made, the drought in Yunnan Province can be effectively monitored.
{"title":"Drought monitoring in Yunnan province with AMSR-E-based data","authors":"Shu Wang, Ruofei Zhong, Qin Li, Mengli Qin","doi":"10.1117/12.910419","DOIUrl":"https://doi.org/10.1117/12.910419","url":null,"abstract":"In this study, the optical depth of vegetation is worked out with Microwave Polarization Difference Index (MPDI) focusing on the drought that hit Yunnan in early 2010 and using AMSR-E data of the first three months of 2010 in Yunnan Province. Inversion of soil moisture is conducted by using Microwave radiative transfer model and Dielectric constant model, and thereupon drought grading is made, so that the drought grades of the first three months of 2010 in most of the regions in Yunnan Province are obtained. By verifying the retrieval results by means of the soil moisture data collected from ground-based measurements, the conclusion of this study is drawn: with the research method by which soil moisture is retrieved from AMSR-E data, and thereupon the drought grading is made, the drought in Yunnan Province can be effectively monitored.","PeriodicalId":340728,"journal":{"name":"China Symposium on Remote Sensing","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133925306","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Detailed data of spatial and temporal distribution and radiative properties of aerosols are required for assessment on aerosol direct radiative forcing. In recent years, with the development of remote sensing instruments as well as corresponding sophisticated inversion algorithms, the global aerosol distribution can be acquired by satellite remote sensing. The aerosol optical depth in the areas with high surface albedo can be inversed by the latest MODIS deep blue algorithm with good complementarity to the applicable areas with traditional dark target inversion scheme. Based on both algorithms, the distribution of aerosol optical depth over land areas of China in 2005 was provided, with an averaged value 0.31. Moreover, the aerosol optical depths are high in spring and summer while low value in autumn and winter, and greatly different in different areas. In addition, the surface albedo data inversed by MODIS and MISR were coupled into the self-developed radiative model,called RAD01. The aerosol direct radiative forcing at the top of atmosphere (TOA), on the surface and in the atmosphere over land areas of China were calculated as -7±2Wm-2, -21.9 ±6.4Wm-2 and 4.9±4.3Wm-2 respectively. Due to the strong absorptivity of aerosols over land areas of China, the aerosol radiative forcing on the surface was three times larger than that at TOA, with a strong heating effect on the atmosphere.
{"title":"Assessment on aerosol direct radiative forcing over China land areas based on satellite data","authors":"Lin Chen, G. Shi, Biao Wang, Peng Zhang","doi":"10.1117/12.910427","DOIUrl":"https://doi.org/10.1117/12.910427","url":null,"abstract":"Detailed data of spatial and temporal distribution and radiative properties of aerosols are required for assessment on aerosol direct radiative forcing. In recent years, with the development of remote sensing instruments as well as corresponding sophisticated inversion algorithms, the global aerosol distribution can be acquired by satellite remote sensing. The aerosol optical depth in the areas with high surface albedo can be inversed by the latest MODIS deep blue algorithm with good complementarity to the applicable areas with traditional dark target inversion scheme. Based on both algorithms, the distribution of aerosol optical depth over land areas of China in 2005 was provided, with an averaged value 0.31. Moreover, the aerosol optical depths are high in spring and summer while low value in autumn and winter, and greatly different in different areas. In addition, the surface albedo data inversed by MODIS and MISR were coupled into the self-developed radiative model,called RAD01. The aerosol direct radiative forcing at the top of atmosphere (TOA), on the surface and in the atmosphere over land areas of China were calculated as -7±2Wm-2, -21.9 ±6.4Wm-2 and 4.9±4.3Wm-2 respectively. Due to the strong absorptivity of aerosols over land areas of China, the aerosol radiative forcing on the surface was three times larger than that at TOA, with a strong heating effect on the atmosphere.","PeriodicalId":340728,"journal":{"name":"China Symposium on Remote Sensing","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115110356","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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