Proposal for an international effort aimed at quantifying the impact of a realistic representation of vegetation/land cover on seasonal climate forecasts (GLACE-VEG)

Several works have been showing the importance of vegetation/land cover in forcing interannual climate anomalies and in modulating the influence from soil moisture and/or snow. The aim of this initiative is to exploit the latest available observational data over land to improve the representation of vegetation and land cover that can positively contribute to skillful short-term (seasonal) climate predictions. However, the lack of observations in the past has often determined diverging representations of the processes related to land cover and vegetation among different land surface models. It is therefore fundamental to use the multi-model approach.

A coordinated multi-model prediction experiment will be designed to demonstrate the improvements of the predictions at seasonal time scale due to the enhanced representation of land cover and vegetation. Building from already established efforts (e.g. SNOWGLACE, LS3MIP, ESM-snowMIP, LS4P, CONFESS) we will involve the climate prediction community to develop a common experimental protocol for a multi-model coordinated experiment for the robust evaluation of the performance effects on state-of-the-art dynamical prediction systems. In addition, the verification of the coordinated multi-model predictions will provide understanding and guidance about the better approaches to pursue in the future to model land-vegetation processes.

The initial group of cooperative institutions include ISAC-CNR, ECMWF, Meteo France, while other relevant modeling groups already expressed interest to join. It is expected that a good representation of the centres previously involved in GLACE-2 initiative will participate in this coordinated effort.

The details of experimental protocol will be implemented during the second half of 2022. Simulations are expected to begin in 2023. To facilitate the spread of the initiative among the prediction community and the engagement with stakeholders, a proposal for a new Community Activity in the framework of GEO has been submitted. The initiative is also supported by the GEWEX-GLASS panel that will push it further within the related community.