This study investigates the impact of marine heatwaves (MHWs) on the Southern Ocean ecosystem, focusing on their effects on primary production. Using satellite and model data (1982-2021), the researchers characterized MHW spatiotemporal patterns, identified their drivers (sea-air heat fluxes, vertical diffusion), and explored their relationship with marine biogeochemistry. They found that increasing MHW activity enhances net primary production through water column stabilization, particularly in subantarctic areas where sea ice decrease also plays a role. Zonal asymmetry in primary producer responses was also observed. The results highlight the role of MHWs in promoting carbon assimilation in the Southern Ocean, influencing the oceanic carbon cycle under climate change.

Manuel Fernández-Barba, Oleg Belyaev, I. Emma Huertas, Gabriel Navarro