A paper published with PML scientists outlines the new, increased capability of ‘ERSEM’, currently the only marine ecosystem model that covers the plankton food-web, microbial processes, the benthic ecosystem, and the carbonate system.
ERSEM (European Regional Seas Ecosystem Model) was developed in the nineties and now has a world-wide user base, is the subject of over 200 peer-reviewed publications and is one of the most established ecosystem models for the lower trophic levels of the marine food-web in scientific literature. It is also the ecosystem component of operational services provided by the UK Met Office and the Copernicus Marine Environment Monitoring Service for the North West European shelf of the European Commission.
Addition and revision of model components in recent years have enlarged the scope of the model, from the European shelf seas to marine environments across the globe. The revised ERSEM model includes the iron cycle, calcification, a light model based on inherent optical properties and a more detailed representation of the microbial loop; giving scientists a much more comprehensive view of our oceans and how they might respond to future climate change scenarios.
The study, published in Geoscientific Model Development, provides example cases for mid-latitude and sub-tropical locations, verifying the quality of the model ecosystem representation by comparison against in-situ data.
The improved ERSEM model provides users with a unified system for simulating and analysing lower trophic levels of the marine ecosystem across the globe, under present-day and future conditions. It therefore is an ideal platform for research, operational forecasting and projections of future climate change.
As part of the new ERSEM release, the underlying code has been redesigned from the ground up as a flexible modelling platform based on FABM, giving the user complete control over the structure and parametrization of the ecosystem. The new software is based on the same mathematical framework of the classical ERSEM as presented in the paper and is fully capable of replicating its results, but adds the ability to easily add or remove processes and groups. This allows the model system to be custom tailored to any new scientific question, societal challenge or computational constraint. The ERSEM code and pre-built software for Windows are available for download following registration here.
Image: Mean distribution of phytoplankton biomass at the sea surface measured in chlorophyll-a concentration