Abstract

Met Office seasonal predictions are made with the GloSea coupled forecasting system. The (NEMO) ocean and (CICE) sea ice components of GloSea are initialised using analysis fields from the FOAM ocean-sea ice analysis and forecast system. FOAM assimilates satellite and in-situ observations of temperature, salinity, sea level anomaly and sea ice concentration each day using the NEMOVAR 3D -Var scheme. Sea ice thickness is not yet assimilated by FOAM but the Met Office are currently developing capability to assimilate sea ice freeboard and thickness observations from CryoSat-2 and SMOS sensors within the NEMOVAR 3D -Var framework.  

Here we present the findings of a recent study undertaken to assess the impact on the evolution of sea ice seasonal forecasts of initialising with CryoSat2-derived thickness observations. We will show that the initialisation of thickness leads to improved skill for seasonal predictions of Arctic summer sea ice extent and ice-edge location whilst highlighting persistent biases in the modelled thickness distribution.