ORCHIDEE-ICE_AlbedoOptimisation ...

• Main Author: Maignan, Fabienne
• Format: Software
• Language: English
• Published: ESPRI/IPSL 2023
• Subjects: Models/Analyses; LSM; CARBONYL SULFIDE; Atmospheric composition and air quality; Statistics for Analysis, modelling and assimilation SAMA; Greenland; Ice Sheet
• Online Access: https://dx.doi.org/10.14768/e59644bf-2ab2-4826-8409-7ec83f9c56e3; https://data.ipsl.fr/catalog/metadata/e59644bf-2ab2-4826-8409-7ec83f9c56e3

Greenland ice sheet mass loss continues to accelerate as global temperatures increase. The surface albedo of the ice sheet determines the amount of absorbed solar energy, which is a key factor in driving surface snow and ice melting. Satellite retrieved albedo allows us to compare and optimise modelled albedo over the entirety of the ice sheet. We optimise the parameters of the albedo scheme in the ORCHIDEE land surface model for three random years taken over the 2000–2017 period and validate over the remaining years. In particular, we want to improve the albedo at the edges of the ice sheet since they correspond to ablation areas and show the greatest variations in runoff and surface mass balance. By giving a larger weight to points at the ice sheet's edge, we improve the model-data fit by reducing the RMSD by over 25 % for the whole ice sheet for the summer months. This improvement is consistent for all years, even those not used in the calibration step. We conclude by showing which additional model ...