Variability in the sensitivity among model simulations of permafrost and carbon dynamics in the permafrost region between 1960 and 2009

• Published in: Global Biogeochemical Cycles
• Main Authors: McGuire, A.D., Koven, C., Lawrence, D.M., Clein, J.S., Xia, J., Beer, C., Burke, E., Chen, G., Chen, X., Delire, C., Jafarov, E., MacDougall, A., Marchenko, S., Nicolsky, D., Peng, S., Rinke, A., Saito, K., Zhang, W., Alkama, R., Bohn, T.J., Ciais, P., Decharme, B., Hayes, D.J., Ekici, A., Gouttevin, I., Hajima, T., Ji, D., Krinner, G., Lettenmaier, D.P., Luo, Y., Miller, P.A., Moore, J.C., Romanovsky, V., Schaedel, C., Schaefer, K., Schuur, E.A.G., Smith, B., Sueyoshi, T., Zhuang, Q
• Other Authors: US GEOLOGICAL SURVEY UNIVERSITY OF ALASKA FAIRBANKS USA, LAWRENCE BERKELEY NATIONAL LABORATORY CALIFORNIA USA, NATIONAL CENTER FOR ATMOSPHERIC RESEARCH BOULDER COLORADO USA, INSTITUTE OF ARCTIC BIOLOGY UNIVERSITY OF ALASKA FAIRBANKS USA, EAST CHINA NORMAL UNIVERSITY SHANGHAI CHN, ACES STOCKHOLM SWE, MET OFFICE HADLEY CENTRE EXETER GBR, OAK RIDGE NATIONAL LABORATORY TENNESSEE USA, UNIVERSITY OF WAHINGTON SEATTLE USA, GAME TOULOUSE FRA, INSTITUTE OF ARCTIC ALPINE RESEARCH UNIVERSITY OF COLORADO BOULDER USA, SCHOOL OF EARTH AND OCEAN SCIENCES UNIVERSITY OF VICTORIA BRITISH COLUMBIA CAN, GEOPHYSICAL INSTITUTE UNIVERSITY OF ALASKA FAIRBANKS USA, CNRS UMR 8212 LSCE GIF SUR YVETTE FRA, ALFRED WEGENER INSTITUTE HELMHOLTZ CENTRE FOR POLAR AND MARINE RESEARCH POTSDAM DEU, JAPAN AGENCY FOR MARINE EARTH SCIENCE AND TECHNOLOGY YOKOHAMA JPN, DEPARTMENT OF PHYSICAL GEOGRAPHY AND ECOSYSTEM SCIENCE LUND UNIVERSITY SWE, SCHOOL OF EARTH AND SPACE EXPLORATION ARIZONA STATE UNIVERSITY TEMPE USA, IRSTEA LYON UR HHLY FRA, COLLEGE OF GLOBAL CHANGE AND EARTH SYSTEM SCIENCE BEIJING NORMAL UNIVERSITY CHN CHN, UNIVERSITE GRENOBLE ALPES CNRS LGGE UMR 5183 GRENOBLE FRA, DEPARTMENT OF GEOGRAPHY UNIVERSITY OF CALIFORNIA LOS ANGELES USA, DEPARTMENT OF MICROBIOLOGY AND PLANT BIOLOGY UNIVERSITY OF OKLAHOMA NORMAN USA, NORTHERN ARIZONA UNIVERSITY FLAGSTAFF USA, NATIONAL SNOW AND ICE DATA CENTER UNIVERSITY OF COLORADO BOULDER USA, PURDUE UNIVERSITY WEST LAFAYETTE INDIANA USA
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2016
• Subjects: NEIGE; CARBONE; SIMULATION; MODELISATION; CHANGEMENT CLIMATIQUE; PERMAFROST; PERMAFROST MODELLING; CARBON DYNAMICS; LAND-SURFACE MODELS; MODEL SENSITIVITY; GROSS PRIMARY PRODUCTION; CO2-ENHANCEMENT; CLIMATE CHANGE; snow; carbon; modelling; climatic change; permafrost
• Online Access: https://irsteadoc.irstea.fr/cemoa/PUB00052560

A significant portion of the large amount of carbon (C) currently stored in soils of the permafrost region in the Northern Hemisphere has the potential to be emitted as the greenhouse gases CO2 and CH4 under a warmer climate. In this study we evaluated the variability in the sensitivity of permafrost and C in recent decades among land surface model simulations over the permafrost region between 1960 and 2009. The 15 model simulations all predict a loss of near-surface permafrost (within 3 m) area over the region, but there are large differences in the magnitude of the simulated rates of loss among the models (0.2 to 58.8 x 103 km2 yrâˆ'1). Sensitivity simulations indicated that changes in air temperature largely explained changes in permafrost area, although interactions among changes in other environmental variables also played a role. All of the models indicate that both vegetation and soil C storage together have increased by 156 to 954 Tg C yrâˆ'1 between 1960 and 2009 over the permafrost region even though model analyses indicate that warming alone would decrease soil C storage. Increases in gross primary production (GPP) largely explain the simulated increases in vegetation and soil C. The sensitivity of GPP to increases in atmospheric CO2 was the dominant cause of increases in GPP across the models, but comparison of simulated GPP trends across the 1982-2009 period with that of a global GPP data set indicates that all of the models overestimate the trend in GPP. Disturbance also appears to be an important factor affecting C storage, as models that consider disturbance had lower increases in C storage than models that did not consider disturbance. To improve the modeling of C in the permafrost region, there is the need for the modeling community to standardize structural representation of permafrost and carbon dynamics among models that are used to evaluate the permafrost C feedback and for the modeling and observational communities to jointly develop data sets and methodologies to more effectively benchmark models.