Atmospheric CO2 inversion validation using vertical profile measurements: Analysis of four independent inversion models

[1] We present the results of a validation of atmospheric inversions of CO2 fluxes using four transport models. Each inversion uses data primarily from surface stations, combined with an atmospheric transport model, to estimate surface fluxes. The validation (or model evaluation) consists of running these optimized fluxes through the forward model and comparing the simulated concentrations with airborne concentration measurements. We focus on profiles from Cape Grim, Tasmania, and Carr, Colorado, while using other profile sites to test the generality of the comparison. Fits to the profiles are generally worse than to the surface data from the inversions and worse than the expected model-data mismatch. Thus inversion estimates are generally not consistent with the profile measurements. The TM3 model does better by some measures than the other three models. Models perform better over Tasmania than Colorado, and other profile sites bear out a general improvement from north to south and from continental to marine locations. There are also errors in the interannual variability of the fit, consistent in time and common across models. This suggests real variations in sources visible to the profile but not the surface measurements.

[1]  Fabienne Maignan,et al.  CO2 surface fluxes at grid point scale estimated from a global 21 year reanalysis of atmospheric measurements , 2010 .

[2]  F. Chevallier,et al.  AIRS-based versus flask-based estimation of carbon surface fluxes , 2009 .

[3]  P. Rayner,et al.  Interannual variability of the global carbon cycle (1992–2005) inferred by inversion of atmospheric CO2 and δ13CO2 measurements , 2008 .

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

[5]  J. Randerson,et al.  New constraints on Northern Hemisphere growing season net flux , 2007 .

[6]  Kevin R. Gurney,et al.  TransCom 3 inversion intercomparison: Impact of transport model errors on the interannual variability of regional CO2 fluxes, 1988–2003 , 2006 .

[7]  Kevin R. Gurney,et al.  Maximum likelihood estimation of covariance parameters for Bayesian atmospheric trace gas surface flux inversions , 2005 .

[8]  Shamil Maksyutov,et al.  Interannual and decadal changes in the sea‐air CO2 flux from atmospheric CO2 inverse modeling , 2005 .

[9]  R. Francey.  Recent Record Growth in Atmospheric CO2 Levels , 2005 .

[10]  P. Ciais,et al.  Multiple constraints on regional CO2 flux variations over land and oceans , 2005 .

[11]  Shamil Maksyutov,et al.  Analysis of atmospheric CO2 growth rates at Mauna Loa using CO2 fluxes derived from an inverse model , 2005 .

[12]  P. Tans,et al.  A geostatistical approach to surface flux estimation of atmospheric trace gases , 2004 .

[13]  Philippe Ciais,et al.  Transcom 3 inversion intercomparison: Model mean results for the estimation of seasonal carbon sources and sinks , 2004, Global Biogeochemical Cycles.

[14]  John C. Lin,et al.  Toward constraining regional‐scale fluxes of CO2 with atmospheric observations over a continent: 1. Observed spatial variability from airborne platforms , 2003 .

[15]  S. Houweling,et al.  Time-dependent atmospheric CO2 inversions based on interannually varying tracer transport , 2003 .

[16]  Ian G. Enting,et al.  Inverse problems in atmospheric constituent transport , 2002 .

[17]  I. C. Prentice,et al.  Climatic Control of the High-Latitude Vegetation Greening Trend and Pinatubo Effect , 2002, Science.

[18]  Taro Takahashi,et al.  Towards robust regional estimates of CO2 sources and sinks using atmospheric transport models , 2002, Nature.

[19]  Hidekazu Matsueda,et al.  Aircraft observation of carbon dioxide at 8–13 km altitude over the western Pacific from 1993 to 1999 , 2002 .

[20]  T Kaminski,et al.  Inverse modeling of atmospheric carbon dioxide fluxes. , 2001, Science.

[21]  Corinne Le Quéré,et al.  Regional changes in carbon dioxide fluxes of land and oceans since 1980. , 2000, Science.

[22]  Clive D Rodgers,et al.  Inverse Methods for Atmospheric Sounding: Theory and Practice , 2000 .

[23]  P. Rayner,et al.  The interannual variability of the global carbon cycle , 1999 .

[24]  Ian G. Enting,et al.  Reconstructing the recent carbon cycle from atmospheric CO2, δ13C and O2/N2 observations* , 1999 .

[25]  M. Wahlen,et al.  Interannual extremes in the rate of rise of atmospheric carbon dioxide since 1980 , 1995, Nature.

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

[27]  C. Rödenbeck.  Estimating CO2 sources and sinks from atmospheric mixing ratio measurements using a global inversion of atmospheric transport , 2005 .

[28]  B. C. Pak.  Vertical structure Of atmospheric trace gases over Southeast Australia , 2000 .

[29]  P. P. Tans,et al.  Changes in oceanic and terrestrial carbon uptake since 1982 , 1995, Nature.