TY - JOUR
T1 - Soil carbon model alternatives for ECHAM5/JSBACH climate model
T2 - Evaluation and impacts on global carbon cycle estimates
AU - Thum, T.
AU - Risnen, P.
AU - Sevanto, S.
AU - Tuomi, Mikko
AU - Reick, C.
AU - Vesala, T.
AU - Raddatz, T.
AU - Aalto, T.
AU - Jrvinen, H.
AU - Altimir, N.
AU - Pilegaard, K.
AU - Nagy, Z.
AU - Rambal, S.
AU - Liski, J.
N1 - Thum, T., et al. (2011), 'Soil carbon model alternatives for ECHAM5/JSBACH climate model: Evaluation and impacts on global carbon cycle estimates', Journal of Geophysical Research, Vol. 116, G02028, published 29 June 2011. The version of record is available at doi:10.1029/2010JG001612
© 2011 American Geophysical Union.
PY - 2011/6/29
Y1 - 2011/6/29
N2 - The response of soil organic carbon to climate change might lead to significant feedbacks affecting global warming. This response can be studied by coupled climate-carbon cycle models but so far the description of soil organic carbon cycle in these models has been quite simple. In this work we used the coupled climate-carbon cycle model ECHAM5/JSBACH (European Center/Hamburg Model 5/Jena Scheme for Biosphere-Atmosphere Coupling in Hamburg) with two different soil carbon modules, namely (1) the original soil carbon model of JSBACH called CBALANCE and (2) a new soil carbon model Yasso07, to study the interaction between climate variability and soil organic carbon. Equivalent ECHAM5/JSBACH simulations were conducted using both soil carbon models, with freely varying atmospheric CO2 for the last 30 years (1977-2006). In this study, anthropogenic CO2 emissions and ocean carbon cycle were excluded. The new model formulation produced soil carbon stock estimates that were much closer to measured values. It also captured better the seasonal cycle of the direct CO2 exchange measurements at the three grassland sites considered (RMS error reduced by 12%), while for the five forest sites also analyzed, the results were ambiguous and the RMS error was 12% larger for Yasso07 than for CBALANCE. As a response to climatic changes, Yasso07 showed greater release of soil carbon to the atmosphere than the original model formulation during the years 1977-2006. This emphasizes the need for better understanding the processes affecting soil carbon stocks and their turnover rates to predict the climatic feedbacks.
AB - The response of soil organic carbon to climate change might lead to significant feedbacks affecting global warming. This response can be studied by coupled climate-carbon cycle models but so far the description of soil organic carbon cycle in these models has been quite simple. In this work we used the coupled climate-carbon cycle model ECHAM5/JSBACH (European Center/Hamburg Model 5/Jena Scheme for Biosphere-Atmosphere Coupling in Hamburg) with two different soil carbon modules, namely (1) the original soil carbon model of JSBACH called CBALANCE and (2) a new soil carbon model Yasso07, to study the interaction between climate variability and soil organic carbon. Equivalent ECHAM5/JSBACH simulations were conducted using both soil carbon models, with freely varying atmospheric CO2 for the last 30 years (1977-2006). In this study, anthropogenic CO2 emissions and ocean carbon cycle were excluded. The new model formulation produced soil carbon stock estimates that were much closer to measured values. It also captured better the seasonal cycle of the direct CO2 exchange measurements at the three grassland sites considered (RMS error reduced by 12%), while for the five forest sites also analyzed, the results were ambiguous and the RMS error was 12% larger for Yasso07 than for CBALANCE. As a response to climatic changes, Yasso07 showed greater release of soil carbon to the atmosphere than the original model formulation during the years 1977-2006. This emphasizes the need for better understanding the processes affecting soil carbon stocks and their turnover rates to predict the climatic feedbacks.
UR - http://www.scopus.com/inward/record.url?scp=79960178124&partnerID=8YFLogxK
U2 - 10.1029/2010JG001612
DO - 10.1029/2010JG001612
M3 - Article
AN - SCOPUS:79960178124
SN - 0148-0227
VL - 116
JO - Journal of Geophysical Research: Atmospheres
JF - Journal of Geophysical Research: Atmospheres
IS - 2
M1 - G02028
ER -