C021-0013
Sea ice and atmospheric predictability: preliminary results using HadGEM3 and EC-Earth

Wednesday, 9 December 2020
Poster
Daniela Flocco1, Ed Hawkins1, Leandro Ponsoni2, Francois E Massonnet3, Daniel Lee Feltham4 and Thierry Fichefet3, (1)University of Reading, National Centre for Atmospheric Science, Reading, United Kingdom, (2)UCLouvain, Louvain-la-Neuve, Belgium, (3)Université Catholique de Louvain, Georges Lemaître Centre for Earth and Climate Research, Earth and Life Institute, Louvain-La-Neuve, Belgium, (4)University of Reading, Centre for Polar Observation and Modelling, Department of Meteorology, Reading, RG6, United Kingdom
Abstract:
Arctic sea ice extent has steadily declined in the past 30 years. Regional information on the sea ice presence and its impact on oceanic and atmospheric circulation is of growing interest, especially if these impacts are predictable.

Here we examine the influence of Arctic sea-ice thickness observations on the predictability of the sea-ice and atmospheric circulation using idealised ‘data denial’ experiments. We perform paired sets of ensembles with the HadGEM3 GCM using different initial conditions retrieved from a present-day control run. Parallel experiments were performed with GCM EC-Earth.

One set of ensembles start with complete information about the sea-ice conditions and is treated as “truth”, and one set has degraded sea ice information. We investigate how the pairs of ensembles predict the subsequent evolution of the sea-ice state, sea level pressure and circulation within the Arctic with the aim of quantifying the value of sea-ice observations for improving predictions.

We also present an inter-model comparison with EC-Earth of the skill gain evolution in the two models for the first three months of simulations.

<< Previous Abstract | Next Abstract >>