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    题名 作者 年代 出处 被引量
1A retrieval algorithm for TanSat XCO_2 observation: Retrieval experiments using GOSAT data显示文摘This study developed a highly accurate retrieval algorithm for the column-averaged CO2 dry-air mixing ratio (XCO2) to be observed by TanSat, China's carbon dioxide observation satellite that will be launched in 2015. The Greenhouse Gases Observing Satellite (GOSAT) L1B spectrum was applied in retrieval experiment, and the results were validated with ground-observed measurements from the Total Column Carbon Observing Network (TCCON). At mid-latitudes, most results fell in the 1% error region, which correspond to the performance of GOSAT algorithm. The results also showed seasonal variation in XCO2 in both hemispheres.LIU Yi YANG DongXu CAI ZhaoNan 2013Chinese Science Bulletin2013,58,13:30
2The TanSat mission: preliminary global observations显示文摘The Chinese global carbon dioxide monitoring satellite (Tan Sat) was launched successfully in December2016 and has completed its on-orbit tests and calibration. Tan Sat aims to measure the atmospheric column-averaged dry air mole fractions of carbon dioxide (XCO_2) with a precision of 4 ppm at the regional scale, and in addition, to derive global and regional CO2fluxes. Progress towards these objectives is reviewed and the first scientific results from Tan Sat measurements are presented. Tan Sat on-orbit tests indicate that the Atmospheric Carbon dioxide Grating Spectrometer is in normal working status and is beginning to produce L1B products. The preliminary Tan Sat XCO_2products have been retrieved by an algorithm and compared to NASA Orbiting Carbon Observatory-2 (OCO-2) measurements during an overlapping observation period. Furthermore, the XCO_2retrievals have been validated against eight groundsite measurement datasets from the Total Carbon Column Observing Network, for which the preliminary conclusion is that Tan Sat has met the precision design requirement, with an average bias of 2.11 ppm.The first scientific observations are presented, namely, the seasonal distributions of XCO_2over land on a global scale.Yi Liu Jing Wang Lu Yao Xi Chen Zhaonan Cai Dongxu Yang Zengshan Yin Songyan Gu Longfei Tian Naimeng Lu Daren Lyu 2018Science Bulletin2018,63,18:23
3First Global Carbon Dioxide Maps Produced from Tan Sat Measurements显示文摘1.The need for global carbon monitoring from space and the Tan Sat mission Global warming is a major problem,for which carbon dioxide(CO_2 )is the main greenhouse gas involved in heating the troposphere.However,the poor availability of global CO_2 measurements makes it difficult to estimate CO_2 emissions accurately.Satellite measurements would be very helpful for understanding the global CO_2 flux distribution if the CO_2 column-averaged dry-air mole fraction(XCO_2 )Dongxu YANG Yi LIU Zhaonan CAI Xi CHEN Lu YAO Daren LU 2018Advances in Atmospheric Sciences2018,35,6:16
4An advanced carbon dioxide retrieval algorithm for satellite measurements and its application to GOSAT observations显示文摘An advanced carbon dioxide retrieval algorithm for satellite observations has been developed at the Institute of Atmospheric Physics, Chinese Academy of Sciences. The algorithm is tested using Greenhouse gases Observing SATellite(GOSAT) L1 B data and validated using the Total Column Carbon Observing Network(TCCON) measurements. The retrieved XCO2 agrees well with TCCON measurements in a low bias of 0.15 ppmv and RMSE of 1.48 ppmv, and captured the seasonal variation and increasing of XCO2 in Northern and Southern Hemisphere, respectively, as other measurements.Dongxu Yang Yi Liu Zhaonan Cai Jianbo Deng Jing Wang Xi Chen 2015Science Bulletin2015,60,23:12
5Satellite UV-Vis spectroscopy:implications for air quality trends and their driving forces in China during 2005-2017显示文摘Abundances of a range of air pollutants can be inferred from satellite UV-Vis spectroscopy measurements by using the unique absorption signatures of gas species.Here,we implemented several spectral fitting methods to retrieve tropospheric NO_(2),SO_(2),and HCHO from the ozone monitoring instrument(OMI),with radiative simulations providing necessary information on the interactions of scattered solar light within the atmosphere.We analyzed the spatial distribution and temporal trends of satellite-observed air pollutants over eastern China during 2005-2017,especially in heavily polluted regions.We found significant decreasing trends in NO_(2) and SO_(2) since 2011 over most regions,despite varying temporal features and turning points.In contrast,an overall increasing trend was identified for tropospheric HCHO over these regions in recent years.Furthermore,generalized additive models were implemented to understand the driving forces of air quality trends in China and assess the effectiveness of emission controls.Our results indicated that although meteorological parameters,such as wind,water vapor,solar radiation and temperature,mainly dominated the day-to-day and seasonal fluctuations in air pollutants,anthropogenic emissions played a unique role in the long-term variation in the ambient concentrations of NO_(2),SO_(2),and HCHO in the past 13 years.Generally,recent declines in NO_(2) and SO_(2) could be attributed to emission reductions due to effective air quality policies,and the opposite trends in HCHO may urge the need to control anthropogenic volatile organic compound(VOC)emissions.Chengxin Zhang Cheng Liu Qihou Hu Zhaonan Cai Wenjing Su Congzi Xia Yizhi Zhu Siwen Wang Jianguo Liu 2019Light(Science & Applications)2019,8,1:11
6Monitoring Carbon Dioxide from Space:Retrieval Algorithm and Flux Inversion Based on GOSAT Data and Using CarbonTracker-China显示文摘Monitoring atmospheric carbon dioxide(CO_2) from space-borne state-of-the-art hyperspectral instruments can provide a high precision global dataset to improve carbon flux estimation and reduce the uncertainty of climate projection. Here, we introduce a carbon flux inversion system for estimating carbon flux with satellite measurements under the support of 'The Strategic Priority Research Program of the Chinese Academy of Sciences—Climate Change: Carbon Budget and Relevant Issues'. The carbon flux inversion system is composed of two separate parts: the Institute of Atmospheric Physics Carbon Dioxide Retrieval Algorithm for Satellite Remote Sensing(IAPCAS), and Carbon Tracker-China(CT-China), developed at the Chinese Academy of Sciences. The Greenhouse gases Observing SATellite(GOSAT) measurements are used in the carbon flux inversion experiment. To improve the quality of the IAPCAS-GOSAT retrieval, we have developed a post-screening and bias correction method, resulting in 25%–30% of the data remaining after quality control. Based on these data, the seasonal variation of XCO_2(column-averaged CO_2dry-air mole fraction) is studied, and a strong relation with vegetation cover and population is identified. Then, the IAPCAS-GOSAT XCO_2 product is used in carbon flux estimation by CT-China. The net ecosystem CO_2 exchange is-0.34 Pg C yr^(-1)(±0.08 Pg C yr^(-1)), with a large error reduction of 84%, which is a significant improvement on the error reduction when compared with in situ-only inversion.Dongxu YANG Huifang ZHANG Yi LIU Baozhang CHEN Zhaonan CAI Daren Lü 2017Advances in Atmospheric Sciences2017,34,8:9
7The Chinese carbon cycle data-assimilation system(Tan-Tracker)显示文摘In this study,the Chinese carbon cyle dataassimilation system Tan-Tracker is developed based on the atmospheric chemical transport model(GEOS-Chem)platform.Tan-Tracker is a dual-pass data-assimilation system in which both CO2concentrations and CO2fluxes are simultaneously assimilated from atmospheric observations.It has several advantages,including its advanced data-assimilation method,its highly efficient computing performance,and its simultaneous assimilation of CO2concentrations and CO2fluxes.Preliminary observing system simulation experiments demonstrate its robust performance with high assimilation precision,making full use of observations.The Tan-Tracker system can only assimilate in situ observations for the moment.In the future,we hope to extend Tan-Tracker with functions for using satellite measurements,which will form the quasioperational Chinese carbon cycle data-assimilation system.Xiangjun Tian Zhenghui Xie Zhaonan Cai Yi Liu Yu Fu Huifang Zhang 2014Chinese Science Bulletin2014,59,14:7
8Detection of Anthropogenic CO_(2) Emission Signatures with TanSat CO_(2) and with Copernicus Sentinel-5 Precursor(S5P)NO_(2) Measurements:First Results显示文摘China’s first carbon dioxide(CO_(2))measurement satellite mission,TanSat,was launched in December 2016.This paper introduces the first attempt to detect anthropogenic CO_(2) emission signatures using CO_(2) observations from TanSat and NO_(2) measurements from the TROPOspheric Monitoring Instrument(TROPOMI)onboard the Copernicus Sentinel-5 Precursor(S5P)satellite.We focus our analysis on two selected cases in Tangshan,China and Tokyo,Japan.We found that the TanSat XCO_(2) measurements have the capability to capture the anthropogenic variations in the plume and have spatial patterns similar to that of the TROPOMI NO_(2) observations.The linear fit between TanSat XCO_(2) and TROPOMI NO_(2) indicates the CO_(2)-to-NO_(2) ratio of 0.8×10^(-16) ppm(molec cm^(-2))^(-1) in Tangshan and 2.3×10^(-16) ppm(molec cm^(-2))^(-1) in Tokyo.Our results align with the CO_(2)-to-NOx emission ratios obtained from the EDGAR v6 emission inventory.Dongxu YANG Janne HAKKARAINEN Yi LIU Iolanda IALONGO Zhaonan CAI Johanna TAMMINEN 2023Advances in Atmospheric Sciences2023,40,1:6
9The First Global Carbon Dioxide Flux Map Derived from TanSat Measurements显示文摘Space-borne measurements of atmospheric greenhouse gas concentrations provide global observation constraints for top-down estimates of surface carbon flux.Here,the first estimates of the global distribution of carbon surface fluxes inferred from dry-air CO_2 column (XCO_2) measurements by the Chinese Global Carbon Dioxide Monitoring Scientific Experimental Satellite (Tan Sat) are presented.An ensemble transform Kalman filter (ETKF) data assimilation system coupled with the GEOS-Chem global chemistry transport model is used to optimally fit model simulations with the Tan Sat XCO_2 observations,which were retrieved using the Institute of Atmospheric Physics Carbon dioxide retrieval Algorithm for Satellite remote sensing (IAPCAS).High posterior error reduction (30%–50%) compared with a priori fluxes indicates that assimilating satellite XCO_2 measurements provides highly effective constraints on global carbon flux estimation.Their impacts are also highlighted by significant spatiotemporal shifts in flux patterns over regions critical to the global carbon budget,such as tropical South America and China.An integrated global land carbon net flux of 6.71±0.76 Gt C yr^(-1) over12 months (May 2017–April 2018) is estimated from the Tan Sat XCO_2 data,which is generally consistent with other inversions based on satellite data,such as the JAXA GOSAT and NASA OCO-2 XCO_2 retrievals.However,discrepancies were found in some regional flux estimates,particularly over the Southern Hemisphere,where there may still be uncorrected bias between satellite measurements due to the lack of independent reference observations.The results of this study provide the groundwork for further studies using current or future Tan Sat XCO_2 data together with other surfacebased and space-borne measurements to quantify biosphere–atmosphere carbon exchange.Dongxu YANG Yi LIU Liang FENG Jing WANG Lu YAO Zhaonan CAI Sihong ZHU Naimeng LU Daren LYU 2021Advances in Atmospheric Sciences2021,38,9:5
10Analysis of XCO_2 retrieval sensitivity using simulated Chinese Carbon Satellite(TanSat) measurements显示文摘We present a study on the retrieval sensitivity of the column-averaged dry-air mole fraction of CO2(XCO2) for the Chinese carbon dioxide observation satellite(TanSat) with a full physical forward model and the optimal estimation technique. The forward model is based on the vector linearized discrete ordinate radiative transfer model(VLIDORT) and considers surface reflectance, gas absorption, and the scattering of air molecules, aerosol particles, and cloud particles. XCO2 retrieval errors from synthetic TanSat measurements show solar zenith angle(SZA), albedo dependence with values varying from 0.3 to 1 ppm for bright land surface in nadir mode and 2 to 8 ppm for dark surfaces like snow. The use of glint mode over dark oceans significantly improves the CO2 information retrieved. The aerosol type and profile are more important than the aerosol optical depth, and underestimation of aerosol plume height will introduce a bias of 1.5 ppm in XCO2. The systematic errors due to radiometric calibration are also estimated using a forward model simulation approach.CAI ZhaoNan LIU Yi YANG DongXu 2014Science China Earth Sciences2014,57,8:5
11Effects of spectral sampling rate and range of CO_2 absorption bands on XCO_2 retrieval from TanSat hyperspectral spectrometer显示文摘The spectral sampling rate and range of CO2absorption bands are critical for the optimal design of hyperspectral instrument for CO2observation satellite.Undersampling of spectra in space-based spectrometer significantly contaminates signals measured in the CO21.61 lm-band.The CO2dry-air column(XCO2)error due to spectral undersampling can be up to*1 ppm,which is the target precision of the Chinese Carbon Satellite(TanSat)for a single sounding.Undersampling error depends on surface albedo,solar zenith angle,and scattering properties in the atmosphere.The spectral sampling rate is recommended to be greater than 2.0 pixels per full width at half maximum to avoid undersampling.Reduction of spectral resolution and the use of narrower spectral regions can improve spectral sampling with little changes in CO2retrieval sensitivity without losing much information.The full-band approach provides direct constraints on the wavelength-dependent surface albedo and particle scattering from the measurements.To keep a broader band,we recommend reduction of the spectral resolution by a factor of two.Yi Liu Zhaonan Cai Dongxu Yang Yuquan Zheng Minzheng Duan Daren L 2014Chinese Science Bulletin2014,59,14:5
12CH_4 retrieval from hyperspectral satellite measurements in shortwave infrared: sensitivity study and preliminary test with GOSAT data显示文摘One of the important science requirements of monitoring atmospheric methane abundances from hyperspectral measurements is to establish a highly accurate retrieval algorithm.This paper aimed to describe a retrieval algorithm based on a series of sensitivity study with an effective and accurate forward model,which was applied to realize online calculation of absorption coefficient and backscattered solar radiance.The sensitivity study consisted of band selection,interference factors analysis,and retrieval model construction.The band selection analysis indicated that the 1.65 lm band(5,900–6,150 cm-1)associated with the 2.06 lm band(4,800–4,900 cm-1)retained more than 90%of the information content of CH4,CO2,and temperature,and more than 85%of that of H2O in the retrieval.Investigation of the interference factors showed that H2O,temperature,and CO2will cause unacceptable errors if they are not revised.This also showed that revising temperature and H2O with a profile model is more efficient than with a temperature offset and a H2O scale factor model.A preliminarily test using the Greenhouse gases Observing SATellite Level 1B spectral data indicated that most of the retrieval errors were less than 1%,which is acceptable for methane flux estimation.Jianbo Deng Yi Liu Dongxu Yang Zhaonan Cai 2014Chinese Science Bulletin2014,59,14:5
13A New TanSat XCO2 Global Product towards Climate Studies显示文摘The 1st Chinese carbon dioxide(CO2)monitoring satellite mission,TanSat,was launched in 2016.The 1st TanSat global map of CO2 dry-air mixing ratio(XCO2)measurements over land was released as version 1 data product with an accuracy of 2.11 ppmv(parts per million by volume).In this paper,we introduce a new(version 2)TanSat global XCO2 product that is approached by the Institute of Atmospheric Physics Carbon dioxide retrieval Algorithm for Satellite remote sensing(IAPCAS),and the European Space Agency(ESA)Climate Change Initiative plus(CCI+)TanSat XCO2 product by University of Leicester Full Physics(UoL-FP)retrieval algorithm.The correction of the measurement spectrum improves the accuracy(−0.08 ppmv)and precision(1.47 ppmv)of the new retrieval,which provides opportunity for further application in global carbon flux studies in the future.Inter-comparison between the two retrievals indicates a good agreement,with a standard deviation of 1.28 ppmv and a bias of−0.35 ppmv.Dongxu YANG Yi LIU Hartmut BOESCH Lu YAO Antonio DI NOIA Zhaonan CAI Naimeng LU Daren LYU Maohua WANG Jing WANG Zengshan YIN Yuquan ZHENG 2021Advances in Atmospheric Sciences2021,38,1:4
14A New Global Solar-induced Chlorophyll Fluorescence(SIF)Data Product from TanSat Measurements显示文摘The Chinese Carbon Dioxide Observation Satellite Mission(TanSat)is the third satellite for global CO2 monitoring and is capable of detecting weak solar-induced chlorophyll fluorescence(SIF)signals with its advanced technical characteristics.Based on the Institute of Atmospheric Physics Carbon Dioxide Retrieval Algorithm for Satellite Remote Sensing(IAPCAS)platform,we successfully retrieved the TanSat global SIF product spanning the period of March 2017 to February 2018 with a physically based algorithm.This paper introduces the new TanSat SIF dataset and shows the global seasonal SIF maps.A brief comparison between the IAPCAS TanSat SIF product and the data-driven SVD(singular value decomposition)SIF product is also performed for follow-up algorithm optimization.The comparative results show that there are regional biases between the two SIF datasets and the linear correlations between them are above 0.73 for all seasons.The future SIF data product applications and requirements for SIF space observation are discussed.Lu YAO Dongxu YANG Yi LIU Jing WANG Liangyun LIU Shanshan DU Zhaonan CAI Naimeng LU Daren LYU Maohua WANG Zengshan YIN 2021Advances in Atmospheric Sciences2021,38,3:3
15TanSat Mission Achievements: from Scientific Driving to Preliminary Observations显示文摘The Chinese global carbon dioxide monitoring satellite(TanSat)was successfully launched in December 2016 and has completed its on-orbit tests and calibration.TanSat aims to measure the atmospheric Carbon Dioxide column-averaged dry air mole fractions(X_(CO_2))with a precision of 4 ppm at the regional scale,and further to derive the CO_2 global and regional fluxes.Progress toward these objectives is reviewed and the first scientific results from TanSat measurements are presented.During the design phase,Observation System Simulation Experiments(OSSE)on TanSat measurements performed prior to launch measurements using a nadir and a glint alternative mode when considering the balance of stable measurements and reduces the flux uncertainty(64%).The constellation measurements of two satellites indicate an extra 10%improvement in flux inversion if the satellite measurements have no bias and similar precision.The TanSat on-orbit test indicates that the instrument is stable and beginning to produce X_(CO_2)products.The preliminary TanSat measurements have been validated with Total Carbon Column Observing Network(TCCON)measurements and have inter-compared with OCO-2 measurements in an overlap measurement.LIU Yi WANG Jing YAO Lu CHEN Xi CAI Zhaonan YANG Dongxu YIN Zengshan GU Songyan TIAN Longfei LU Naimeng L Daren 2018空间科学学报2018,38,5:2
16Monitoring Greenhouses Gases over China Using Space-Based Observations Monitoring Greenhouses Gases over China Using Space-Based Observations显示文摘The atmospheric carbon dioxide(CO 2)concentration has increased to more than 405 parts per million(ppm.1 ppm=10-6 m/s 2)in 2017 due to human activities such as deforestation,land-use change and burning of fossil fuels.Although there is broad scientific consensus on the damaging consequences of the change in climate associated with increasing concentrations of greenhouse gases,fossil CO 2 emissions have continued to increase in recent years mainly from rapidly developing economies and China is now the largest emitter of CO 2 generating about 30%of all emissions globally.To allow more reliable forecast of the future state of the carbon cycle and to support the efforts for mitigation greenhouse gas emissions,a better understanding of the global and regional carbon budget is needed.Space-based measurements of CO 2 can provide the necessary observations with dense coverage and sampling to provide improved constrains on of carbon fluxes and emissions.The Chinese Global Carbon Dioxide Monitoring Scientific Experimental Satellite(TanSat)was established by the National High Technology Research and Development Program of China with the main objective of monitoring atmospheric CO 2 and CO 2 fluxes at the regional and global scale.TanSat has been successfully launched in December 2016 and as part of the Dragon programme of ESA and the Ministry of Science and Technology(MOST),a team of researchers from Europe(UK and Finland)and China has evaluated early TanSat data and contrast it against data from the GOSAT mission and models.In this manuscript,we report on retrieval intercomparisons of TanSat data using two different retrieval algorithms,on validation efforts for the Eastern Asia region using GOSAT CO 2 data and first assessments of TanSat and GOSAT CO 2 data against model calculations using the GEOS-Chem model.Hartmut BOESCH Yi LIU Paul I PALMER Johanna TAMMINEN Jasdeep S ANAND Zhaonan CAI Ke CHE Huilin CHEN Xi CHEN Liang FENG Janne HAKKARAINEN Pauli HEIKKINEN Nikoleta KALAITZI Rigel KIVI Robert PARKER Peter SOMKUTI Jing WANG Alex WEBB Dongxu YANG Lu YAO You YI 2020Journal of Geodesy and Geoinformation Science2020,3,4:2
17Dynamic formation of extreme ozone minimum events over the Tibetan Plateau during northern winters 1987-2001显示文摘Liu Chuanxi Liu Yi Cai Zhaonan Gao Shouting Bian Jianchun Liu Xiong Chance Kelly 2010Journal of Geophysical Research. Atmospheres2010,,18:1
18A Madden-Julian Oscillation-triggered record ozone minimum over the Tibetan Plateau in December 2003 and its association with stratospheric 'low-ozone pockets'显示文摘Liu Chuanxi Liu Yi Cai Zhaonan Gao Shouting Daren Kyr?l? Erkki 2009Geophysical Research Letters2009,,15:1
19A multi-location joint field observation of the stratosphere and troposphere over the Tibetan Plateau显示文摘The unique geographical location and high altitude of the Tibetan Plateau can greatly influence regional weather and climate.In particular, the Asian summer monsoon(ASM) anticyclone circulation system over the Tibetan Plateau is recognized to be a significant transport pathway for water vapor and pollutants to enter the stratosphere. To improve understanding of these physical processes, a multi-location joint atmospheric experiment was performed over the Tibetan Plateau from late July to August in 2018, funded by the fiveyear(2018–2022) STEAM(stratosphere and troposphere exchange experiment during ASM) project, during which multiple platforms/instruments—including long-duration stratospheric balloons, dropsondes, unmanned aerial vehicles, special sounding systems, and ground-based and satellite-borne instruments—will be deployed. These complementary methods of data acquisition are expected to provide comprehensive atmospheric parameters(aerosol, ozone, water vapor, CO_2, CH_4, CO, temperature, pressure,turbulence, radiation, lightning and wind); the richness of this approach is expected to advance our comprehension of key mechanisms associated with thermal, dynamical, radiative, and chemical transports over the Tibetan Plateau during ASM activity.JinQiang Zhang Yi Liu HongBin Chen ZhaoNan Cai ZhiXuan Bai LingKun Ran Tao Luo Jing Yang YiNan Wang YueJian Xuan YinBo Huang XiaoQing Wu JianChun Bian DaRen Lu 2019Earth and Planetary Physics2019,3,2:1
20A Madden-Julian Oscillation-triggered record ozone minimum over the Tibetan Plateau in December 2003 and its association with stratospheric 'low-ozone pockets'显示文摘Liu Chuanxi Liu Yi Cai Zhaonan Gao Shouting Daren Kyr?l? Erkki 2009Geophysical Research Letters2009,,15:1
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