Articles | Volume 7, issue 6
https://doi.org/10.5194/gmd-7-3111-2014
https://doi.org/10.5194/gmd-7-3111-2014
Development and technical paper
 | 
18 Dec 2014
Development and technical paper |  | 18 Dec 2014

A simplified permafrost-carbon model for long-term climate studies with the CLIMBER-2 coupled earth system model

K. A. Crichton, D. M. Roche, G. Krinner, and J. Chappellaz

Abstract. We present the development and validation of a simplified permafrost-carbon mechanism for use with the land surface scheme operating in the CLIMBER-2 earth system model. The simplified model estimates the permafrost fraction of each grid cell according to the balance between modelled cold (below 0 °C) and warm (above 0 °C) days in a year. Areas diagnosed as permafrost are assigned a reduction in soil decomposition rate, thus creating a slow accumulating soil carbon pool. In warming climates, permafrost extent reduces and soil decomposition rates increase, resulting in soil carbon release to the atmosphere. Four accumulation/decomposition rate settings are retained for experiments within the CLIMBER-2(P) model, which are tuned to agree with estimates of total land carbon stocks today and at the last glacial maximum. The distribution of this permafrost-carbon pool is in broad agreement with measurement data for soil carbon content. The level of complexity of the permafrost-carbon model is comparable to other components in the CLIMBER-2 earth system model.

Share
Download
Short summary
Permafrost is ground that remains frozen for two or more consecutive years. An estimated 50% of...
Share