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A method for evaluating bias in global measurements of CO2 total columns from space

Journal Article


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Abstract


  • We describe a method of evaluating systematic errors in measurements of total column dry-air mole fractions of CO 2 (X CO2) from space, and we illustrate the method by applying it to the v2.8 Atmospheric CO 2 Observations from Space retrievals of the Greenhouse Gases Observing Satellite (ACOS-GOSAT) measurements over land. The approach exploits the lack of large gradients in X CO2 south of 25° S to identify large-scale offsets and other biases in the ACOS-GOSAT data with several retrieval parameters and errors in instrument calibration. We demonstrate the effectiveness of the method by comparing the ACOS-GOSAT data in the Northern Hemisphere with ground truth provided by the Total Carbon Column Observing Network (TCCON). We use the observed correlation between free-tropospheric potential temperature and X CO2 in the Northern Hemisphere to define a dynamically informed coincidence criterion between the ground-based TCCON measurements and the ACOS-GOSAT measurements. We illustrate that this approach provides larger sample sizes, hence giving a more robust comparison than one that simply uses time, latitude and longitude criteria. Our results show that the agreement with the TCCON data improves after accounting for the systematic errors, but that extrapolation to conditions found outside the region south of 25° S may be problematic (e.g., high airmasses, large surface pressure biases, M-gain, measurements made over ocean). A preliminary evaluation of the improved v2.9 ACOS-GOSAT data is also discussed. © 2011 Author(s).

Authors


  •   Wunch, Debra (external author)
  •   Wennberg, Paul O. (external author)
  •   Toon, Geoffrey C. (external author)
  •   Connor, Brian J. (external author)
  •   Fisher, B (external author)
  •   Osterman, Greg (external author)
  •   Frankenberg, Christian (external author)
  •   Mandrake, L (external author)
  •   O'Dell, Christopher (external author)
  •   Ahonen, P (external author)
  •   Biraud, S C. (external author)
  •   Castano, R (external author)
  •   Cressie, Noel A.
  •   Crisp, David (external author)
  •   Deutscher, Nicholas M.
  •   Eldering, A (external author)
  •   Fisher, M L. (external author)
  •   Griffith, David W. T.
  •   Gunson, M (external author)
  •   Heikkinen, Pauli (external author)
  •   Keppel-Aleks, Gretchen (external author)
  •   Kyro, Esko (external author)
  •   Lindemaier, R (external author)
  •   Macatangay, Ronald (external author)
  •   Mendonca, Joseph (external author)
  •   Messerschmidt, Janina (external author)
  •   Miller, Charles E. (external author)
  •   Morino, Isamu (external author)
  •   Notholt, Justus (external author)
  •   Oyafuso, F A. (external author)
  •   Rettinger, Markus (external author)
  •   Robinson, John (external author)
  •   Roehl, Coleen M. (external author)
  •   Salawitch, R (external author)
  •   Sherlock, Vanessa (external author)
  •   Strong, Kimberly (external author)
  •   Sussmann, Ralf (external author)
  •   Tanaka, T (external author)
  •   Thompson, D R. (external author)
  •   Uchino, Osamu (external author)
  •   Warneke, Thorsten (external author)
  •   Wofsy, Steven C. (external author)

Publication Date


  • 2011

Citation


  • Wunch, D., Wennberg, P. O., Toon, G. C., Connor, B. J., Fisher, B., Osterman, G. B., Frankenberg, C., Mandrake, L., O'Dell, C., Ahonen, P., Biraud, S. C., Castano, R., Cressie, N. A., Crisp, D., Deutscher, N. M., Eldering, A., Fisher, M. L., Griffith, D. W., Gunson, M., Heikkinen, P., Keppel-Aleks, G., Kyro, E., Lindemaier, R., Macatangay, R., Mendonca, J., Messerschmidt, J., Miller, C. E., Morino, I., Notholt, J., Oyafuso, F. A., Rettinger, M., Robinson, J., Roehl, C. M., Salawitch, R. J., Sherlock, V., Strong, K., Sussmann, R., Tanaka, T., Thompson, D. R., Uchino, O., Warneke, T. & Wofsy, S. C. (2011). A method for evaluating bias in global measurements of CO2 total columns from space. Atmospheric Chemistry and Physics, 11 (23), 12317-12337.

Scopus Eid


  • 2-s2.0-83255193678

Ro Full-text Url


  • http://ro.uow.edu.au/cgi/viewcontent.cgi?article=9625&context=infopapers

Ro Metadata Url


  • http://ro.uow.edu.au/infopapers/2289

Has Global Citation Frequency


Number Of Pages


  • 20

Start Page


  • 12317

End Page


  • 12337

Volume


  • 11

Issue


  • 23

Abstract


  • We describe a method of evaluating systematic errors in measurements of total column dry-air mole fractions of CO 2 (X CO2) from space, and we illustrate the method by applying it to the v2.8 Atmospheric CO 2 Observations from Space retrievals of the Greenhouse Gases Observing Satellite (ACOS-GOSAT) measurements over land. The approach exploits the lack of large gradients in X CO2 south of 25° S to identify large-scale offsets and other biases in the ACOS-GOSAT data with several retrieval parameters and errors in instrument calibration. We demonstrate the effectiveness of the method by comparing the ACOS-GOSAT data in the Northern Hemisphere with ground truth provided by the Total Carbon Column Observing Network (TCCON). We use the observed correlation between free-tropospheric potential temperature and X CO2 in the Northern Hemisphere to define a dynamically informed coincidence criterion between the ground-based TCCON measurements and the ACOS-GOSAT measurements. We illustrate that this approach provides larger sample sizes, hence giving a more robust comparison than one that simply uses time, latitude and longitude criteria. Our results show that the agreement with the TCCON data improves after accounting for the systematic errors, but that extrapolation to conditions found outside the region south of 25° S may be problematic (e.g., high airmasses, large surface pressure biases, M-gain, measurements made over ocean). A preliminary evaluation of the improved v2.9 ACOS-GOSAT data is also discussed. © 2011 Author(s).

Authors


  •   Wunch, Debra (external author)
  •   Wennberg, Paul O. (external author)
  •   Toon, Geoffrey C. (external author)
  •   Connor, Brian J. (external author)
  •   Fisher, B (external author)
  •   Osterman, Greg (external author)
  •   Frankenberg, Christian (external author)
  •   Mandrake, L (external author)
  •   O'Dell, Christopher (external author)
  •   Ahonen, P (external author)
  •   Biraud, S C. (external author)
  •   Castano, R (external author)
  •   Cressie, Noel A.
  •   Crisp, David (external author)
  •   Deutscher, Nicholas M.
  •   Eldering, A (external author)
  •   Fisher, M L. (external author)
  •   Griffith, David W. T.
  •   Gunson, M (external author)
  •   Heikkinen, Pauli (external author)
  •   Keppel-Aleks, Gretchen (external author)
  •   Kyro, Esko (external author)
  •   Lindemaier, R (external author)
  •   Macatangay, Ronald (external author)
  •   Mendonca, Joseph (external author)
  •   Messerschmidt, Janina (external author)
  •   Miller, Charles E. (external author)
  •   Morino, Isamu (external author)
  •   Notholt, Justus (external author)
  •   Oyafuso, F A. (external author)
  •   Rettinger, Markus (external author)
  •   Robinson, John (external author)
  •   Roehl, Coleen M. (external author)
  •   Salawitch, R (external author)
  •   Sherlock, Vanessa (external author)
  •   Strong, Kimberly (external author)
  •   Sussmann, Ralf (external author)
  •   Tanaka, T (external author)
  •   Thompson, D R. (external author)
  •   Uchino, Osamu (external author)
  •   Warneke, Thorsten (external author)
  •   Wofsy, Steven C. (external author)

Publication Date


  • 2011

Citation


  • Wunch, D., Wennberg, P. O., Toon, G. C., Connor, B. J., Fisher, B., Osterman, G. B., Frankenberg, C., Mandrake, L., O'Dell, C., Ahonen, P., Biraud, S. C., Castano, R., Cressie, N. A., Crisp, D., Deutscher, N. M., Eldering, A., Fisher, M. L., Griffith, D. W., Gunson, M., Heikkinen, P., Keppel-Aleks, G., Kyro, E., Lindemaier, R., Macatangay, R., Mendonca, J., Messerschmidt, J., Miller, C. E., Morino, I., Notholt, J., Oyafuso, F. A., Rettinger, M., Robinson, J., Roehl, C. M., Salawitch, R. J., Sherlock, V., Strong, K., Sussmann, R., Tanaka, T., Thompson, D. R., Uchino, O., Warneke, T. & Wofsy, S. C. (2011). A method for evaluating bias in global measurements of CO2 total columns from space. Atmospheric Chemistry and Physics, 11 (23), 12317-12337.

Scopus Eid


  • 2-s2.0-83255193678

Ro Full-text Url


  • http://ro.uow.edu.au/cgi/viewcontent.cgi?article=9625&context=infopapers

Ro Metadata Url


  • http://ro.uow.edu.au/infopapers/2289

Has Global Citation Frequency


Number Of Pages


  • 20

Start Page


  • 12317

End Page


  • 12337

Volume


  • 11

Issue


  • 23