Assessment of a multi-tiling energy budget approach in a land surface model, ORCHIDEE-MICT (r8205)

• Main Authors: Xi, Yi, Qiu, Chunjing, Zhang, Yuan, Zhu, Dan, Peng, Shushi, Hugelius, Gustaf, Chang, Jinfeng, Salmon, Elodie, Ciais, Philippe
• Format: Text
• Language: English
• Published: 2023
• Subjects: permafrost
• Online Access: https://doi.org/10.5194/gmd-2023-207; https://gmd.copernicus.org/preprints/gmd-2023-207/

The surface energy budget plays a critical role in terrestrial hydrologic and biogeochemical cycles. Nevertheless, its highly spatial heterogeneity across different vegetation types is still missing in the land surface model, ORCHIDEE-MICT (ORganizing Carbon and Hydrology in Dynamic EcosystEms–aMeliorated Interactions between Carbon and Temperature). In this study, we describe the representation of a multi-tiling energy budget in ORCHIDEE-MICT, and assess its short and long-term impacts on energy, hydrology, and carbon processes. With the specific values of surface properties for each vegetation type, the new version presents warmer surface and soil temperatures, wetter soil moisture, and increased soil organic carbon storage across the Northern Hemisphere. Despite reproducing the absolute values and spatial gradients of surface and soil temperatures from satellite and in-situ observations, the considerable uncertainties in simulated soil organic carbon and hydrologic processes prevent an obvious improvement of temperature bias existing in the original ORCHIDEE-MICT. However, the separation of sub-grid energy budgets in the new version improves permafrost simulation greatly by accounting for the presence of discontinuous permafrost type, which will facilitate various permafrost-related studies in the future.