Assimilation of Atmospheric CO 2 Concentration in the ORCHIDEE Land Surface Model: Exploring the Added Value of Explicit Forest Regrowth Representation
Abstract
The land absorbs a large proportion of human‐induced carbon emissions, yet the spatial distribution of this carbon sink remains uncertain. Land surface models (LSMs) and atmospheric inversions often diverge on the spatial distribution of carbon sink, with models generally underestimating the northern land sink (above 30°N). In this study, we use atmospheric measurements to constrain parameters of the ORganizing Carbon and Hydrology In Dynamic EcosystEms LSM and evaluate whether this improves simulation of terrestrial carbon fluxes. We perform two calibration experiments: one in which the base model is calibrated alone, and another in which it is calibrated after being supplemented with data‐driven estimates of forest post‐disturbance regrowth and fire impacts. In both cases, calibration improves agreement between simulated and observed atmospheric over the 2010–2022 period and reduces the global carbon budget imbalance. It also reconciles with the partitioning of the carbon sink between northern and tropical regions estimated by atmospheric inversions. Including post‐disturbance regrowth not only leads to distinct parameter values but also improves the spatial distribution of land carbon uptake, particularly over Europe where regrowth fluxes are largest, bringing regional patterns closer to those from atmospheric inversions. It also highlights that forest demography must be considered when assimilating atmospheric to obtain more realistic estimates of the spatial distribution of the terrestrial carbon sink.
Related
- Introducing shrubs enhances the representation of high-latitude vegetation and carbon cycling in the ORCHIDEE land surface model
- 4D sensitivity kernels for infrasound atmospheric propagation: considering the need and impact of time dependent observation operators for acoustic wave observations in data assimilation methods
- Subseasonal forecast improvements from sea ice concentration data assimilation in the Antarctic
- Enhancing hydrological representation of the Brahmaputra basin through terrestrial water storage and surface soil moisture Data Assimilation
- ORCHIDEE-Hg v1.0 (rev. 9721): A new global land-surface model for mercury dynamics – Part 1: Model description and evaluation in temperate regions
BibTeX
@article{beylat2026assimilation,
title = {{Assimilation of Atmospheric CO 2 Concentration in the ORCHIDEE Land Surface Model: Exploring the Added Value of Explicit Forest Regrowth Representation}},
author = {Simon Beylat and Philippe Peylin and Nina Raoult and Michael O’sullivan and Antoine Berchet and Frederic Chevallier and Peter Rayner},
journal = {Journal of Advances in Modeling Earth Systems},
year = {2026},
month = sep,
doi = {10.1029/2026ms005874},
url = {https://hal.science/hal-05758233v1},
note = {CC BY-NC 4.0},
}
RIS
TY - JOUR
TI - Assimilation of Atmospheric CO 2 Concentration in the ORCHIDEE Land Surface Model: Exploring the Added Value of Explicit Forest Regrowth Representation
AU - Simon Beylat
AU - Philippe Peylin
AU - Nina Raoult
AU - Michael O’sullivan
AU - Antoine Berchet
AU - Frederic Chevallier
AU - Peter Rayner
PY - 2026
DA - 2026/09/16
JO - Journal of Advances in Modeling Earth Systems
DO - 10.1029/2026ms005874
UR - https://hal.science/hal-05758233v1
AB - The land absorbs a large proportion of human‐induced carbon emissions, yet the spatial distribution of this carbon sink remains uncertain. Land surface models (LSMs) and atmospheric inversions often diverge on the spatial distribution of carbon sink, with models generally underestimating the northern land sink (above 30°N). In this study, we use atmospheric measurements to constrain parameters of the ORganizing Carbon and Hydrology In Dynamic EcosystEms LSM and evaluate whether this improves simulation of terrestrial carbon fluxes. We perform two calibration experiments: one in which the base model is calibrated alone, and another in which it is calibrated after being supplemented with data‐driven estimates of forest post‐disturbance regrowth and fire impacts. In both cases, calibration improves agreement between simulated and observed atmospheric over the 2010–2022 period and reduces the global carbon budget imbalance. It also reconciles with the partitioning of the carbon sink between northern and tropical regions estimated by atmospheric inversions. Including post‐disturbance regrowth not only leads to distinct parameter values but also improves the spatial distribution of land carbon uptake, particularly over Europe where regrowth fluxes are largest, bringing regional patterns closer to those from atmospheric inversions. It also highlights that forest demography must be considered when assimilating atmospheric to obtain more realistic estimates of the spatial distribution of the terrestrial carbon sink.
SN - 1942-2466
ER -