Toward Establishing a Low-cost UAV Coordinated Carbon Observation Network(LUCCN):First Integrated Campaign in China

In this study,we introduce our newly developed measurement-fed-perception self-adaption Low-cost UAV Coordinated Carbon Observation Network(LUCCN)prototype.The LUCCN primarily consists of two categories of instruments,including ground-based and UAV-based in-situ measurement.We use the GMP343,a low-cost non-dispersive infrared sensor,in both ground-based and UAV-based instruments.The first integrated measurement campaign took place in Shenzhen,China,4 May 2023.During the campaign,we found that LUCCN’s UAV component presented significant data-collecting advantages over its ground-based counterpart owing to the relatively high altitudes of the point emission sources,which was especially obvious at a gas power plant in Shenzhen.The emission flux was calculated by a crosssectional flux(CSF)method,the results of which differed from the Open-Data Inventory for Anthropogenic Carbon dioxide(ODIAC).The CSF result was slightly larger than others because of the low sampling rate of the whole emission cross section.The LUCCN system will be applied in future carbon monitoring campaigns to increase the spatiotemporal coverage of carbon emission information,especially in scenarios involving the detection of smaller-scale,rapidly varying sources and sinks.

Detection of Anthropogenic CO_(2) Emission Signatures with TanSat CO_(2) and with Copernicus Sentinel-5 Precursor(S5P)NO_(2) Measurements:First Results

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.

The First Global Carbon Dioxide Flux Map Derived from TanSat Measurements

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.

First Global Carbon Dioxide Maps Produced from Tan Sat Measurements

1.The need for global carbon monitoring from space and the TanSat mission Global warming is a major problem,for which carbon dioxide（CO2 ）is the main greenhouse gas involved in heating the troposphere.However,the poor availability of global CO2 measurements makes it difficult to estimate CO2 emissions accurately.

A New TanSat XCO2 Global Product towards Climate Studies

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.

A New Global Solar-induced Chlorophyll Fluorescence(SIF)Data Product from TanSat Measurements

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.

Cobalt phosphide nanoparticles supported within network of N-doped carbon nanotubes as a multifunctional and scalable electrocatalyst for water splitting

In order to realize industrial production of hydrogen through water splitting,it is essential to develop a cost-efficient and scalable approach to synthesize nonprecious electrocatalysts with sufficiently high activity and stability to replace commercial noble-metal-based electrocatalysts.Herein we synthesize cobalt phosphide nanoparticles dispersed within nitrogen-doped carbon nanotube network(CP@NCNT) via scalable spray drying and thermal treatments.As a multifunctional electrocatalyst,the CP@NCNT hybrid delivers outstanding activity for HER(in both acidic and alkaline electrolytes),OER and overall water splitting.Remarkably,it shows an ultra-low overpotental of 94 mV to obtain 10 mA cm-2 in HER.It also demonstrates outstanding activity in overall water splitting,requiring only 1.619 V to deliver 10 mA cm-2with more than 72 h’ long-term stability.The combination of notable performance,multi-functionality and highly scalable spray-drying synthesis method enables this material as a novel and cost-efficient transition metal-based electrocatalysts for overall water splitting.

Monitoring Carbon Dioxide from Space：Retrieval Algorithm and Flux Inversion Based on GOSAT Data and Using CarbonTracker-China

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.

Monitoring Greenhouses Gases over China Using Space-Based Observations Monitoring Greenhouses Gases over China Using Space-Based Observations

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.

Characterization of Regional Combustion Efficiency usingΔXCO:ΔXCO_(2)Observed by a Portable Fourier-Transform Spectrometer at an Urban Site in Beijing

Measurements of column-averaged dry-air mole fractions of carbon dioxide and carbon monoxide,CO_(2)(XCO_(2))and CO(XCO),were performed throughout 2019 at an urban site in Beijing using a compact Fourier Transform Spectrometer(FTS)EM27/SUN.This data set is used to assess the characteristics of combustion-related CO_(2)emissions of urban Beijing by analyzing the correlated daily anomalies of XCO and XCO_(2)(e.g.,ΔXCO andΔXCO_(2)).The EM27/SUN measurements were calibrated to a 125HR-FTS at the Xianghe station by an extra EM27/SUN instrument transferred between two sites.The ratio ofΔXCO overΔXCO_(2)(ΔXCO:ΔXCO_(2))is used to estimate the combustion efficiency in the Beijing region.A high correlation coefficient(0.86)betweenΔXCO andΔXCO_(2)is observed.The CO:CO_(2)emission ratio estimated from inventories is higher than the observedΔXCO:ΔXCO_(2)(10.46±0.11 ppb ppm^(−1))by 42.54%-101.15%,indicating an underestimation in combustion efficiency in the inventories.DailyΔXCO:ΔXCO_(2)are influenced by transportation governed by weather conditions,except for days in summer when the correlation is low due to the terrestrial biotic activity.By convolving the column footprint[ppm(μmol m-2 s-1)-1]generated by the Weather Research and Forecasting-X-Stochastic Time-Inverted Lagrangian Transport models(WRF-X-STILT)with two fossil-fuel emission inventories(the Multi-resolution Emission Inventory for China(MEIC)and the Peking University(PKU)inventory),the observed enhancements of CO_(2)and CO were used to evaluate the regional emissions.The CO_(2)emissions appear to be underestimated by 11%and 49%for the MEIC and PKU inventories,respectively,while CO emissions were overestimated by MEIC(30%)and PKU(35%)in the Beijing area.

Decadal Methane Emission Trend Inferred from Proxy GOSAT XCH4 Retrievals:Impacts of Transport Model Spatial Resolution

In recent studies,proxy XCH_(4)retrievals from the Japanese Greenhouse gases Observing SATellite(GOSAT)have been used to constrain top-down estimation of CH_(4)emissions.Still,the resulting interannual variations often show significant discrepancies over some of the most important CH_(4)source regions,such as China and Tropical South America,by causes yet to be determined.This study compares monthly CH_(4)flux estimates from two parallel assimilations of GOSAT XCH_(4)retrievals from 2010 to 2019 based on the same Ensemble Kalman Filter(EnKF)framework but with the global chemistry transport model(GEOS-Chem v12.5)being run at two different spatial resolutions of 4°×5°(R4,lon×lat)and 2°×2.5°(R2,lon×lat)to investigate the effects of resolution-related model errors on the derived long-term global and regional CH_(4)emission trends.We found that the mean annual global methane emission for the 2010s is 573.04 Tg yr^(-1)for the inversion using the R4 model,which becomes about 4.4 Tg yr^(-1)less(568.63 Tg yr^(-1))when a finer R2 model is used,though both are well within the ensemble range of the 22 top-down results(2008-17)included in the current Global Carbon Project(from 550 Tg yr^(-1)to 594 Tg yr^(-1)).Compared to the R2 model,the inversion based on the R4 tends to overestimate tropical emissions(by 13.3 Tg yr^(-1)),which is accompanied by a general underestimation(by 8.9 Tg yr^(-1))in the extratropics.Such a dipole reflects differences in tropical-mid-latitude air exchange in relation to the model’s convective and advective schemes at different resolutions.The two inversions show a rather consistent long-term CH_(4)emission trend at the global scale and over most of the continents,suggesting that the observed rapid increase in atmospheric methane can largely be attributed to the emission growth from North Africa(1.79 Tg yr^(-2)for R4 and 1.29 Tg yr^(-2)for R2)and South America Temperate(1.08 Tg yr^(-2)for R4 and 1.21 Tg yr^(-2)for R2)during the first half of the 2010s,and from Eurasia Boreal(1.46 Tg yr^(-2)for R4 and 1.63 Tg yr^(-2)for R2)and Tropical South America(1.72 Tg yr-2 for R4 and 1.43 Tg yr^(-2)for R2)over 2015-19.In the meantime,emissions in Europe have shown a consistent decrease over the past decade.However,the growth rates by the two parallel inversions show significant discrepancies over Eurasia Temperate,South America Temperate,and South Africa,which are also the places where recent GOSAT inversions usually disagree with one other.

Direct Observations of Atmospheric Transport and Stratosphere-Troposphere Exchange from High-Precision Carbon Dioxide and Carbon Monoxide Profile Measurements

The balloon-borne Aircore campaign was conducted in Inner Mongolia,China,on June 13 and 142018,which detected carbon dioxide(CO2)and carbon monoxide(CO)profiles from surface to 24 km,showing strong positive and negative correlations between 8 km and 10 km on 13 and 14 June,respectively.Backward trajectories,meteorological analyses,and CO2 horizontal distributions were combined to interpret this phenomenon.The results indicated that the source region experienced a stratospheric intrusion and exhibited a large horizontal CO2 gradient;namely,lower CO concentrations corresponded to higher CO2 concentrations and vice versa.The laminar structure with multiple origins resulted in the highly negative correlation between CO2 and CO in the upper troposphere on 14 June.The contribution of stratospheric air mass to the upper troposphere and that of tropospheric air mass to the lower stratosphere were 26.7%and24.3%,respectively,based on a mass balance approach.Another interesting phenomenon is that CO2 and CO concentrations increased substantially at approximately 8 km on 13 June.An analysis based on the backward trajectory implied that the air mass possibly came from anthropogenic sources.The slope of CO2/CO representing the anthropogenic sources was 87.3 ppm ppm-1.In addition,the CO2 profile showed that there was a large CO2 gradient of 4 ppm km-1 within the boundary layer on 13 June,and this gradient disappeared on 14 June.

A kinetic resolution accompanied chirality transformation process for asymmetric synthesis of chiral phenol,oxaziridine,andα-hydroxyl cyclic ketone

Chirality transformation is a basic,attractive,and important strategy for obtaining enantioenriched products with desired chiral elements.The reported chirality conversion reaction often involves the process from one type of chirality to another one.To better utilize the chirality transformation strategy for obtaining two or more products with different chiral elements in a single reaction,a new method of kinetic resolution accompanied by a chirality transformation protocol is proposed and successfully realized in this study.This process is used for the asymmetric oxidation of phenol compounds along with the kinetic resolution of oxaziridines.A wide scope of products,including axially chiral phenols,oxaziridines,andα-hydroxyl cyclic ketones were smoothly obtained in high levels of yields and enantioselectivities in the developed method.These products can be readily used for the synthesis of various types of chiral ligands,which are potential choices for other catalytic asymmetric reactions.

Hematite-facilitated microbial ammoxidation for enhanced nitrogen removal in constructed wetlands

Constructed wetlands(CWs)are widely applied for decentralized wastewater treatment.However,achieving efficient removal of ammonia(NH+-N)has proven challenging due to insufficient oxygen.In this study,natural hematite(Fe,O3)was employed as a CW substrate(H-CWs)for the first time to drive anaerobic ammonia oxidation coupled with iron(I)reduction(Feammox).Compared to gravel constructed wetlands(G-CWs),ammonia removal was enhanced by 38.14%to 54.03%and nitrous oxide(N_(2)0)emissions were reduced by 34.60%in H-CWs.The synergistic removal of ammonia and nitrate by H-CWs also resulted in the absence of ammoxidation by-products.Inhibitor and 15N isotope tracer incubations showed that Feammox accounting for approximately 40%of all ammonia removal in the H-CWs.The enrichment of iron phosphate(Fe_(3)Fe_(4)(PO_(4))_(6))promoted the accumulation of the Feammox intermediate compound FeOOH.Microbial nanowires were observed on the surface of H-CW substrates as well,suggesting that the observed biological ammoxidation was most likely related to extracellular electron transfer(EET).Microbial and metagenomics analysis revealed that H-CWs elevated the integrity and enhanced the abundance of functional microorganisms and genes associated with nitrogen metabolism.Overall,the efficient ammonia removal in the absence of O2 together with a reduction in N_(2)O emissions as described in this study may provide useful guidance for hematite-mediated anaerobic ammonia removal in CWs.

The TanSat mission： preliminary global observations

The Chinese global carbon dioxide monitoring satellite （TanSat） was launched successfully in December 2016 and has completed its on-orbit tests and calibration. TanSat aims to measure the atmospheric column-averaged dry air mole fractions of carbon dioxide （XCO2） with a precision of 4 ppm at the regional scale, and in addition, to derive global and regional CO2 fluxes. Progress towards these objectives is reviewed and the first scientific results from TanSat measurements are presented. TanSat on-orbit tests indicate that the Atmospheric Carbon dioxide GratingSpectrometer is in normal working status and is beginning to produce LIB products. The preliminary TanSat XCO2 products have been retrieved by an algorithm and compared to NASA Orbiting Carbon Observatory-2 （OCO-2） measurements during an over- lapping observation period. Furthermore, the XCO2 retrievals have been validated against eight groundsite measurement datasets from the Total Carbon Column Observing Network, for which the preliminary conclusion is that TanSat 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 XCO2 over land on a global scale.

CH_4 retrieval from hyperspectral satellite measurements in shortwave infrared: sensitivity study and preliminary test with GOSAT data

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.

Effects of spectral sampling rate and range of CO_2 absorption bands on XCO_2 retrieval from TanSat hyperspectral spectrometer

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.

One-pot synthesis of arginine modified hydroxyapatite carbon microsphere composites for efficient removal of U(Ⅵ) from aqueous solutions

Uranium was not only the main source of nuclear energy but also one of the long-lived radionuclide.Herein, a novel arginine modified hydroxyapatite carbon microsphere composites(defined as C@HAp/Arg) obtained promptly via a one-step mild hydrothermal method, was applied to remove U(Ⅵ) from aqueous solutions. Based on the characterization of transmission electron microscopy(TEM), scanning electron microscopy(SEM), Fourier transformed infrared spectroscopy(FT-IR), X-ray diffraction(XRD)and X-ray photoelectron spectroscopy(XPS), the synthesized C@HAp/Arg presented globular morphology and abundant functional groups(e.g., —COO^-), which were beneficial to its combination with U(Ⅵ). The interaction mechanism and removal capability of U(Ⅵ) on C@HAp/Arg were studied by batch adsorption technique and spectroscopy analysis. The results implied that U(Ⅵ) can form strong surface complexes on C@HAp/Arg. The kinetics adsorption of U(Ⅵ) followed pseudo-second-order kinetic model with high removal efficiency($95% within 5h at pH 5.0). The adsorption isotherms were well fitted by Langmuir model, implying that U(Ⅵ) uptake on C@HAp/Arg was monolayer coverage. It was found that the maximum adsorption capacities of CSs, C@HAp and C@HAp/Arg toward U(Ⅵ) were calculated to be 23.16,72.09 and 569.66 mg/g, respectively, at 298.15 K and pH 5.0, and thermodynamic parameters revealed that the adsorption processes of U(Ⅵ) were spontaneous and endothermic. In addition, effect of co-existed ions and CO_3^(2-)concentrations demonstrated that U(Ⅵ) adsorption on C@HAp/Arg was weakly interfered by foreign ions and carbonate concentrations. More importantly, the adsorption performance of U(Ⅵ) on C@HAp/Arg was still over $87% after five cycles. Therefore, it was noted that the versatile C@HAp/Arg could be potentially used as a powerful building block for the enrichment and disposal of U(Ⅵ) from aqueous solutions, which could efficiently reduce the potential toxicity of U(Ⅵ) in the U(Ⅵ)-contaminated water.

Advancements in theory of GHG observation from space

As a large developing country,China has the highest level of greenhouse gas(GHG)emissions.The Chinese government is seeking sustainable development and trying to reduce GHG emissions.From the scientific perspective,there

An advanced carbon dioxide retrieval algorithm for satellite measurements and its application to GOSAT observations

An advanced carbon dioxide retrieval algo- rithm 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） LIB 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 vari- ation and increasing of XCO2 in Northern and Southern Hemisphere, respectively, as other measurements.