wiki:GroupActivities/CodeAvalaibilityPublication/ORCHIDEE_gmd-2018-14C

ORCHIDEE_gmd-2018-14C

This version of ORCHIDEE has been used in publication Tifafi, M., Camino-Serrano, M., Hatté, C., Morras, H., Moretti, L., Cornu, S. and Guenet, B.: The use of radiocarbon 14C to constrain soil carbon dynamics in the land surface model ORCHIDEE, Geosci. Model Dev., 11, 4711–4726, doi:10.5194/gmd-2018-102, 2018..

Abstract

Despite the importance of soil as a large component of the terrestrial ecosystems, the soil compartments are not well represented in the Land Surface Models (LSMs). Indeed, soils in current LSMs are generally represented based on a very simplified schema that can induce a misrepresentation of the deep dynamics of soil carbon. Here, we present a new version of the Institut Pierre Simon Laplace (IPSL) Land Surface Model called ORCHIDEE-SOM (ORganizing Carbon and Hydrology in Dynamic EcosystEms? - Soil Organic Matter), incorporating the 14C dynamic in the soil. ORCHIDEE-SOM first simulates soil carbon dynamics for different layers, down to 2 m depth. Second, concentration of dissolved organic carbon and its transport are modeled. Finally, soil organic carbon decomposition is considered taking into account the priming effect. After implementing 14C in the soil module of the model, we evaluated model outputs against observations of soil organic carbon and modern 14C fraction (F14C) for different sites with different characteristics. The model managed to reproduce the soil organic carbon stocks and the F14C along the vertical profiles for the sites examined. However, an overestimation of the total carbon stock was noted, primarily on the surface layer. Due to 14C, it is possible to probe carbon age in the soil, which was found to underestimated. Thereafter, two different tests on this new version have been established. The first was to increase carbon residence time of the passive pool and decrease the flux from the slow pool to the passive pool. The second was to establish an equation of diffusion, initially constant throughout the profile, making it vary exponentially as a function of depth. The first modifications did not improve the capacity of the model to reproduce observations whereas the second test improved both estimation of surface soil carbon stock as well as soil carbon age. This demonstrates that we should focus more on vertical variation of soil parameters as a function of depth, in order to upgrade the representation of global carbon cycle in LSMs, thereby helping to improve predictions of the of soil organic carbon to environmental changes.

Code access

Metadata

DOI 10.14768/20181114001.1
Creator Bertrand Guenet
Affiliation LSCE, CNRS
Title The use of radiocarbon 14C to constrain carbon dynamics in the soil module of the land surface model ORCHIDEE (SVN r5165)
Publisher Institut Pierre Simon Laplace (IPSL)
PublicationYear 2018
ResourceType Software
Rights This software is distributed under the CeCILL license
rightsURI ​http://www.cecill.info/
Subject Land surface model, pixel-to-point comparison, biomass
DataManager Karim Ramage (IPSL)
DataCurator Josefine Ghattas (IPSL)
ContactPerson Bertrand Guenet (LSCE/CNRS)
FundingReference ANR-14-CE01-0004 DeDyCAS,ANR 2010 BLAN 605 Agriped and the European Research Council Synergy grant ERC-2013-SyG-610028 IMBALANCE-P

Last modified 5 years ago Last modified on 2019-03-13T08:49:13+01:00