The Role of Ocean Model Resolution in Simulating Marine Biogeochemical Extremes

Abstract Marine extreme events, such as marine heatwaves (MHWs), low‐oxygen (LOXs), and ocean acidification extremes, are short‐lived phenomena with potentially severe impacts on ecosystems and the services they provide. These events are expected to intensify and become more frequent due to climate change. While resolving mesoscale activity is important for accurately simulating MHWs, the sensitivity of biogeochemical extremes to model resolution remains unclear. We evaluated three global climate models with varying ocean resolutions (1, 0.25, and 0.1) under preindustrial and increasing C forcing. The high‐resolution model (0.1) exhibits more frequent but shorter extreme events, particularly in eddy‐rich regions, when compared to the 0.25 and 1 resolution models. For example, the global frequency of LOX events increased between coarse and eddy‐rich model configurations by 136% while event duration decreased by 62%. These results highlight the importance of mesoscale dynamics in shaping biogeochemical extremes and the need for improved parameterizations of eddy effects, thereby advancing climate extreme predictions.