SI3 Model

The SI3 (Sea Ice modelling Integrated Initiative) climate sea ice model is part of NEMO Nucleus for European Modelling of the Ocean (NEMO) a modelling framework designed to study the ocean and its interactions with the atmosphere, sea ice, and biogeochemical systems over time and space.

SI3 simulates how sea ice responds to atmospheric and oceanic conditions on the timescale of hours and longer and is used to study responses on the short term, seasonally, and for long-term trends, as well as extreme events. Critically, SI3 enables us to enhance understanding of the ‘feedbacks’ between ice, ocean, and atmosphere. This is of particular importance in the polar regions.

Collaborating with the Met Office, British Antarctic Survey (BAS), and National Oceanography Centre (NOC) CPOM contributes to the SI3 sea ice model by implementing new physics into the model and supporting the UK Sea Ice Group and broader polar research community.
European Centre for Medium-Range Weather Forecasts

SI3 is used by the European Centre for Medium-Range Weather Forecasts (ECMWF) and was integrated into their forecasting systems in 2024.

The UK Met Office

SI3 is the sea ice component of the UK Met Office’s GC5 model configuration, used in the HadGEM3: Hadley Centre Global Environment Model and will be used in UKESM2: UK Earth System Model. These models contribute to CMIP7, the international climate modelling comparison project.

NEMO website – A modelling framework of ocean related engines

BISICLES Model

BISICLES is a high-resolution numerical model able to simulate complex interactions between ice sheets, atmosphere, and ocean, along the grounding line where ice sheets meet the ocean.

CPOM leads UK development of the BISICLES ice sheet model.  BISICLES is a state-of-the-art high-performance parallel ice sheet model that employs our own adaptive mesh techniques and data assimilation methods to simulate continental ice sheets. The model runs on a range of computing platforms and is unique in its ability to deliver sub-kilometre resolution at continental scales over millennia, making it highly successful in simulating grounding-line migration.

As part of our commitment to develop and test BISICLES, we have incorporated advanced ice physics and marine melting processes, allowing it to be used over millennial time scales, and we have used our own satellite observations to evaluate the model performance.

We also develop and support its use by the wider scientific community, for example its integration into the UK Earth System Model (UKESM) as well as its application by users in the UK and internationally.

Header image credit: Dr Amy Swiggs