- 1University of Bristol, School of Geographical Sciences, Bristol, United Kingdom of Great Britain – England, Scotland, Wales (mariana.maiapacheco@bristol.ac.uk)
- 2University of York, York, United Kingdom (oliver.andrews@york.ac.uk)
- 3GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany (ifrenger@geomar.de)
- 4University of Gothenburg, Gothenburg, Sweden (bastien.queste@gu.se)
Marine extreme events, such as marine heatwaves (MHW), low oxygen (LOX), and acidity extremes (OAX), must be considered alongside long-term ocean changes as potential ecosystem stressors. In recent years, marine extreme events have been shown to be more frequent, persistent, and intense in response to continued ocean warming, underlining the urgent need for understanding the mechanisms and potential compounding effects. In this study, we investigate the potentially significant role of ocean coherent mesoscale eddies in driving such events by applying an eddy- tracking algorithm to high resolution fields (0.1°) provided by the GFDL CM2.6 ocean model. We quantify the eddy contribution to marine extreme events in target ocean regions near Eastern Boundary Upwelling Systems in both pre-industrial and idealized CO2 forcing experiments. We also use the GFDL CM2-O ensemble to investigate the effect of using different resolution classes (0.1°, 0.25° and 1°) on marine extremes metrics (intensity, duration, and frequency). Here we analyse eddy-rich regions, thus inferring the different effects of eddy-rich, -present and -parameterizing configurations. Our study demonstrates that resolving the mesoscale is the best approach for studying biogeochemical extremes in eddy-rich regions, which presented higher frequency of shorter events with increasing resolution. For LOX the significance of eddies goes to regions beyond those typically characterized as eddy-rich, causing the global LOX frequency to increase significantly by 136% when the resolution was refined from coarse to eddy-rich, shortening the mean duration by 62%. As climate biogeochemical coupled models are very computational and storage-wise costly, it is important to quantify the impacts of mesoscale dynamics onto biogeochemical extremes to improve climate model parameterizations.
How to cite: Maia Pacheco, M., Andrews, O., Frenger, I., Queste, B., and Monteiro, F.: The role of mesoscale eddies as drivers of marine biogeochemical extremes, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-1531, https://doi.org/10.5194/egusphere-egu25-1531, 2025.