ORCHIDEE-MICT (v8.4.1), a land surface model for the high latitudes: model description and validation

Matthieu Guimberteau (1) , Dan Zhu (2) , Fabienne Maignan (1, 3) , Ye Huang , Chao Yue (1) , Sarah Dantec-Nédélec (1) , Catherine Ottle (1, 3) , Albert Jornet-Puig (1) , Ana Bastos (4) , Pierre Laurent (5) , Daniel S Goll (1) , Simon Bowring , Jinfeng Chang (6) , Bertrand Guenet (1, 3) , Marwa Tifafi (1) , Shushi Peng (7) , Gerhard Krinner (8) , Agnès Ducharne (9) , Fuxing Wang (10) , Tao Wang (11, 12) , Xuhui Wang (7) , Yilong Wang (1, 13) , Zun Yin , Ronny Lauerwald (14) , Emilie Joetzjer (15) , Chunjing Qiu (1) , Hyungjun Kim (16) , Philippe Ciais (1, 17)

1 LSCE - Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette]
2 HUST - Huazhong University of Science and Technology [Wuhan]
3 MOSAIC - Modélisation des Surfaces et Interfaces Continentales
4 Instituto de Geociências
5 DPhP - Département de Physique des Particules (ex SPP)
6 LOCEAN - Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques
7 Sino-French Institute for Earth System Science, College of Urban and Environmental Sciences
8 IGE - Institut des Géosciences de l’Environnement
9 METIS - Milieux Environnementaux, Transferts et Interactions dans les hydrosystèmes et les Sols
10 LMD - Laboratoire de Météorologie Dynamique (UMR 8539)
11 Key Laboratory of Alpine Ecology and Biodiversity
12 CAS Center for Excellence in Tibetan Plateau Earth Sciences
13 SATINV - Modélisation INVerse pour les mesures atmosphériques et SATellitaires
14 ULB - Université libre de Bruxelles
15 MSU - Montana State University
16 KAIST - Korea Advanced Institute of Science and Technology
17 ICOS-ATC - ICOS-ATC

The high-latitude regions of the Northern Hemisphere are a nexus for the interaction between land surface physical properties and their exchange of carbon and energy with the atmosphere. At these latitudes, two carbon pools of planetary significance-those of the permanently frozen soils (permafrost), and of the great expanse of boreal forest-are vulnerable to destabilization in the face of currently observed climatic warming, the speed and intensity of which are expected to increase with time. Improved projections of future Arctic and boreal ecosystem transformation require improved land surface models that integrate processes specific to these cold biomes. To this end, this study lays out relevant new parameterizations in the ORCHIDEE-MICT land surface model. These describe the interactions between soil carbon, soil temperature and hydrology, and their resulting feedbacks on water and CO 2 fluxes, in addition to a recently developed fire module. Outputs from ORCHIDEE-MICT, when forced by two climate input datasets, are extensively evaluated against (i) temperature gradients between the atmosphere and deep soils, (ii) the hydrological components comprising the water balance of the largest high-latitude basins, and (iii) CO 2 flux and carbon stock observations. The model performance is good with respect to empirical data, despite a simulated excessive plant water stress and Published by Copernicus Publications on behalf of the European Geosciences Union. 122 M. Guimberteau et al.: ORCHIDEE-MICT, a LSM for the high latitudes a positive land surface temperature bias. In addition, acute model sensitivity to the choice of input forcing data suggests that the calibration of model parameters is strongly forcing-dependent. Overall, we suggest that this new model design is at the forefront of current efforts to reliably estimate future perturbations to the high-latitude terrestrial environment.

Domaines: Océan, Atmosphère; Interfaces continentales, environnement

Matthieu Guimberteau, Dan Zhu, Fabienne Maignan, Ye Huang, Chao Yue, et al.. ORCHIDEE-MICT (v8.4.1), a land surface model for the high latitudes: model description and validation. Geoscientific Model Development, 2018, 11 (1), pp.121 - 163. ⟨10.5194/gmd-11-121-2018⟩. ⟨hal-01806766⟩