CO2 budgeting at the regional scale using a Lagrangian experimental strategy and meso-scale modeling

C. Sarrat, J. Noilhan, P. Lacarrere, P.J.H. Masson, E. Ceschia, P. Ciais, H. Dolman, J.A. Elbers, C. Gerbig, N. Jarosz

Research output: Contribution to journalArticleAcademicpeer-review

9 Citations (Scopus)


An atmospheric Lagrangian experiment for regional CO2 budgeting with aircraft measurements took place during the CarboEurope Regional Experiment Strategy campaign (CERES) in south-west France, in June 2005. The atmospheric CO2 aircraft measurements taken upstream and downstream of an active and homogeneous pine forest revealed a CO2 depletion in the same air mass, using a Lagrangian strategy. This field experiment was analyzed with a meteorological meso-scale model interactively coupled with a surface scheme, with plant assimilation, ecosystem respiration, anthropogenic CO2 emissions and sea fluxes. First, the model was carefully validated against observations made close to the surface and in the atmospheric boundary layer. Then, the carbon budget was evaluated using the numerous CERES observations, by upscaling the surface fluxes observations, and using the modeling results, in order to estimate the relative contribution of each physical process. A good agreement is found between the two methods which use the same vegetation map: the estimation of the regional CO2 surface flux by the Eulerian meso-scale model budget is close to the budget deduced from the upscaling of the observed surface fluxes, and found a budget between -9.4 and -12.1 µmol.m-2.s-1, depending on the size of the considered area. Nevertheless, the associated uncertainties are rather large for the upscaling method and reach 50%. A third method, using Lagrangian observations of CO2 estimates a regional CO2 budget a few different and more scattered, (-16.8 µmol.m-2.s-1 for the small sub-domain and -8.6 µmol.m-2.s-1 for the larger one). For this budgeting method, we estimate a mean of 31% error, mainly arising from the time of integration between the two measurements of the Lagrangian experiment. The paper describes in details the three methods to assess the regional CO2 budget and the associated errors
Original languageEnglish
Pages (from-to)113-127
Number of pages15
Publication statusPublished - 2009


  • climatic change
  • carbon dioxide
  • models
  • surface layers
  • emission
  • hapex-mobilhy
  • atmospheric co2
  • surface
  • parameters
  • resolution
  • inversion
  • database
  • fluxes


Dive into the research topics of 'CO2 budgeting at the regional scale using a Lagrangian experimental strategy and meso-scale modeling'. Together they form a unique fingerprint.
  • ESS-CC

    Project: Other

Cite this