Carbon Dioxide Retrieval from TanSat Observations and Validation with TCCON Measurements

In this study we present the retrieval of the column-averaged dry air mole fraction of carbon dioxide (XCO2) from the TanSat observations using the ACOS (Atmospheric CO2 Observations from Space) algorithm. The XCO2 product has been validated with collocated ground-based measurements from the Total Carbon Column Observing Network (TCCON) for 2 years of TanSat data from 2017 to 2018. Based on the correlation of the XCO2 error over land with goodness of fit in three spectral bands at 0.76, 1.61 and 2.06 μm, we applied an a posteriori bias correction to TanSat retrievals. For overpass averaged results, XCO2 retrievals show a standard deviation (SD) of ~2.45 ppm and a positive bias of ~0.27 ppm compared to collocated TCCON sites. The validation also shows a relatively higher positive bias and variance against TCCON over high-latitude regions. Three cases to evaluate TanSat target mode retrievals are investigated, including one field campaign at Dunhuang with measurements by a greenhouse gas analyzer deployed on an unmanned aerial vehicle and two cases with measurements by a ground-based Fourier-transform spectrometer in Beijing. The results show the retrievals of all footprints, except footprint-6, have relatively low bias (within ~2 ppm). In addition, the orbital XCO2 distributions over Australia and Northeast China between TanSat and the second Orbiting Carbon Observatory (OCO-2) on 20 April 2017 are compared. It shows that the mean XCO2 from TanSat is slightly lower than that of OCO-2 with an average difference of ~0.85 ppm. A reasonable agreement in XCO2 distribution is found over Australia and Northeast China between TanSat and OCO-2.

[1]  Justus Notholt,et al.  Total Column Carbon Observing Network (TCCON) Collection: GGG2014 Site: Bialystok , 2015 .

[2]  Tatsuya Yokota,et al.  Retrieval algorithm for CO 2 and CH 4 column abundances from short-wavelength infrared spectral observations by the Greenhouse gases observing satellite , 2010 .

[3]  Justus Notholt,et al.  Total Column Carbon Observing Network (TCCON) Site: Bremen , 2014 .

[4]  Justus Notholt,et al.  Total Column Carbon Observing Network (TCCON) Site: Orleans , 2014 .

[5]  M. I. Mead,et al.  Infrared atmospheric sounding interferometer correlation interferometry for the retrieval of atmospheric gases: the case of H2O and CO2. , 2011, Applied optics.

[6]  Tatsuya Yokota,et al.  PPDF‐based method to account for atmospheric light scattering in observations of carbon dioxide from space , 2008 .

[7]  Geoffrey C. Toon,et al.  Total Column Carbon Observing Network (TCCON), Site: Pasadena, California , 2015 .

[8]  Tatsuya Yokota,et al.  Global Concentrations of CO2 and CH4 Retrieved from GOSAT: First Preliminary Results , 2009 .

[9]  Christof Janssen,et al.  Total Column Carbon Observing Network (TCCON) Site: Paris , 2014 .

[10]  Kohei Arai,et al.  Total Column Carbon Observing Network (TCCON) Site: Saga , 2014 .

[11]  Ilse Aben,et al.  Uncertainties in the space-based measurements of CO2 columns due to scattering in the Earth's atmosphere , 2007 .

[12]  Hartmut Boesch,et al.  Orbiting Carbon Observatory: Inverse method and prospective error analysis , 2008 .

[13]  Rebecca Castano,et al.  The ACOS CO 2 retrieval algorithm – Part 1: Description and validation against synthetic observations , 2011 .

[14]  Jie Chen,et al.  Validation of Column-Averaged Dry-Air Mole Fraction of CO2 Retrieved from OCO-2 Using Ground-Based FTS Measurements , 2018, Journal of Meteorological Research.

[15]  Geoffrey C. Toon,et al.  Total Column Carbon Observing Network (TCCON) Site: Park Falls , 2014 .

[16]  David Crisp,et al.  Comparisons of the Orbiting Carbon Observatory-2 (OCO-2) X CO 2 measurements with TCCON , 2016 .

[17]  Brian J. Connor,et al.  Total Column Carbon Observing Network (TCCON) Site: Darwin , 2014 .

[18]  Alain Chedin,et al.  Midtropospheric CO2 concentration retrieval from AIRS observations in the tropics , 2004 .

[19]  J. Randerson,et al.  An atmospheric perspective on North American carbon dioxide exchange: CarbonTracker , 2007, Proceedings of the National Academy of Sciences.

[20]  P. Rayner,et al.  The utility of remotely sensed CO2 concentration data in surface source inversions , 2001 .

[21]  Rebecca Castano,et al.  A method for evaluating bias in global measurements of CO 2 total columns from space , 2011 .

[22]  Peter Bergamaschi,et al.  Atmospheric carbon gases retrieved from SCIAMACHY by WFM-DOAS: version 0.5 CO and CH 4 and impact of calibration improvements on CO 2 retrieval , 2006 .

[23]  Tatsuya Yokota,et al.  An improved photon path length probability density function–based radiative transfer model for space‐based observation of greenhouse gases , 2009 .

[24]  Hartmut Boesch,et al.  Global satellite observations of column-averaged carbon dioxide and methane: The GHG-CCI XCO2 and XCH4 CRDP3 data set , 2017 .

[25]  Pierre Friedlingstein,et al.  Uncertainties in CMIP5 Climate Projections due to Carbon Cycle Feedbacks , 2014 .

[26]  Tae-Young Goo,et al.  Carbon dioxide retrieval from OCO-2 satellite observations using the RemoTeC algorithm and validation with TCCON measurements , 2018, Atmospheric Measurement Techniques.

[27]  Isamu Morino,et al.  Revised (R1) 2014 GGG TCCON measurements from Rikubetsu , 2016 .

[28]  M. Fladeland,et al.  Greenhouse gas analyzer for measurements of carbon dioxide, methane, and water vapor aboard an unmanned aerial vehicle , 2012 .

[29]  Thomas P. Kurosu,et al.  A linearized discrete ordinate radiative transfer model for atmospheric remote-sensing retrieval , 2001 .

[30]  Ilse Aben,et al.  Retrievals of atmospheric CO2 from simulated space-borne measurements of backscattered near-infrared sunlight: accounting for aerosol effects. , 2009, Applied optics.

[31]  Olivier Talagrand,et al.  Eulerian backtracking of atmospheric tracers. I: Adjoint derivation and parametrization of subgrid‐scale transport , 2006 .

[32]  C. Cox.  Statistics of the sea surface derived from sun glitter , 1954 .

[33]  Hartmut Boesch,et al.  Global Characterization of CO2 Column Retrievals from Shortwave-Infrared Satellite Observations of the Orbiting Carbon Observatory-2 Mission , 2011, Remote. Sens..

[34]  Tatsuya Yokota,et al.  Detection of optical path in spectroscopic space‐based observations of greenhouse gases: Application to GOSAT data processing , 2011 .

[35]  D. Griffith,et al.  Solar Fourier transform infrared spectra (Wollongong) , 2014 .

[36]  Ralf Sussmann,et al.  Total Column Carbon Observing Network (TCCON) Site: Garmisch , 2014 .

[37]  David Crisp,et al.  The Orbiting Carbon Observatory (OCO) mission , 2004 .

[38]  Wu Liu,et al.  Prelaunch Radiometric Calibration of the TanSat Atmospheric Carbon Dioxide Grating Spectrometer , 2018, IEEE Transactions on Geoscience and Remote Sensing.

[39]  Yi Liu,et al.  A retrieval algorithm for TanSat XCO2 observation: Retrieval experiments using GOSAT data , 2013 .

[40]  Justus Notholt,et al.  The Total Carbon Column Observing Network , 2011, Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences.

[41]  Pauli Heikkinen,et al.  Total Column Carbon Observing Network (TCCON) Site: Sodankyla , 2014 .

[42]  Philippe Ciais,et al.  Spaceborne remote sensing of greenhouse gas concentrations , 2010 .

[43]  David Crisp,et al.  The on-orbit performance of the Orbiting Carbon Observatory-2 (OCO-2) instrument and its radiometrically calibrated products , 2016 .

[44]  Peter Bergamaschi,et al.  Carbon Monoxide, Methane and Carbon Dioxide Columns Retrieved from SCIAMACHY by WFM-DOAS: Year 2003 Initial Data Set , 2005 .

[45]  G. Thuillier,et al.  The Solar Spectral Irradiance from 200 to 2400 nm as Measured by the SOLSPEC Spectrometer from the Atlas and Eureca Missions , 2003 .

[46]  Jean-Noël Thépaut,et al.  Estimating atmospheric CO2 from advanced infrared satellite radiances within an operational 4D-Var data assimilation system: Methodology and first results , 2004 .

[47]  Akihiko Kuze,et al.  Consistent satellite XCO 2 retrievals from SCIAMACHY and GOSAT using the BESD algorithm , 2015 .

[48]  Frank Hase,et al.  Total Column Carbon Observing Network (TCCON) Site: Izana , 2014 .

[49]  Robert J. D. Spurr,et al.  A fast linearized pseudo-spherical two orders of scattering model to account for polarization in vertically inhomogeneous scattering–absorbing media , 2007 .

[50]  Tatsuya Yokota,et al.  Parameterization of aerosol and cirrus cloud effects on reflected sunlight spectra measured from space: application of the equivalence theorem. , 2006, Applied optics.

[51]  Rebecca Castano,et al.  The ACOS CO 2 retrieval algorithm – Part II: Global X CO 2 data characterization , 2012 .