The Arctic is highly susceptible to the projected climatic changes in the future that could influence carbon cycling at high latitudes. Modelling provides a flexible framework to assess changes in ecosystem functioning, however, model development is focused primarily on growing season conditions. Recently, there has been more emphasis on evaluating non-growing season processes and their importance.

The WINTERGAP project is therefore focused on improving physical winter process representation in the LPJ-GUESS dynamic vegetation model. The developments will address the three following winter processes;

1. Snow insulation: a new multi-layer snow scheme will be included to enable analysing snow-vegetation-soil interactions, affecting permafrost conditions.
2. Cold season fluxes: a dynamic soil gas reservoir for CO₂ and CH₄ will be defined to introduce the capability to simulate shoulder period and cold season carbon fluxes.
3. Browning events: frost damage is to be included, making it possible to simulate the observed tissue damage in the region, due to extreme weather conditions.

Lastly, we set out to assess winter contribution to the permafrost-carbon feedback and the local as well as global implications.

The planned adjustments are set out to improve the model’s capability to capture wintertime phenomena, characteristic to the Arctic region. This would make LPJ-GUESS fitting for further investigation about how greenhouse gas fluxes, vegetation and soil conditions are expected to change by a changing climate.