How eddies affect our climate

Eddies come in a range of sizes, with diameters from only a few metres to several kilometres. Their influence on the climate depends on their size. Although the existence of these eddies has been known about for some time, we still have limited quantitative information on their role, also bearing in mind the impacts of a warming climate (Beech et al. 2022). A new EU-financed project aims to change that: with the aid of “European Eddy Rich Earth System Models” (EERIE), eddies will be more realistically represented in climate models – i.e., by the laws of physics rather than empirical parametrisations.

EERIE’s goal is to help produce a new generation of Earth system models (ESMs). To do so, it will focus on improving the simulation of mesoscale eddies, which, depending on the region, can be anywhere from five to 40 kilometres wide. The modelling improvements will include e.g. the inclusion of open channels of water (“leads”) in sea ice, where the ocean influences the atmosphere via powerful heat fluxes. “The technological hurdles to achieving these high-resolution simulations are immense,” says Prof Thomas Jung, responsible for coordinating the project at the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI). “In order to allow quantitative statements, EERIE will have to achieve a simulation rate of up to five simulated years per day on the latest pre-exascale supercomputers available in Europe. Here, efficiency is a key factor – also to keep the simulations’ energy consumption and CO₂ footprint to a minimum.” In order to implement, save and analyse these complex high-resolution simulations, the researchers will have to work hand in hand with software engineers to develop radically new software technologies.

In the course of the project, the researchers also plan to develop new simulation protocols, contributing to national and international climate change assessments in the process. In this way, EERIE is to yield useful and directly applicable climate information, and to make valuable contributions in preparation for the IPCC’s next Assessment Report.

The project budget is over 10 million euros. 17 partner institutions are involved, including seven universities. The kick-off event for EERIE took place on 23 and 24 February 2023. The project, which officially began on 1 January 2023, will continue for four years.