WHIRLS · The impacts of ocean fine-scale whirls on climate and ecosystems

WHIRLS is about small processes having large-scale impacts. Heat and carbon are the currencies of regional and global climate, constantly exchanged between the ocean and the atmosphere. This exchange is strongly influenced by fine-scales ocean eddies—whirls—that flux heat and carbon towards, or away from, the air-sea interface. When the ocean gives up heat and carbon to the atmosphere, climate is warmer and wetter, and vice versa. Carbon that is fluxed towards the air-sea interface, where sunlight is available, can be taken up by phytoplankton that form the base of the oceanic food web. Eddies and fronts alter vertical nutrient fluxes and ocean stratification which help shape biodiversity and ecosystems. The proliferation of fine-scale processes, and their interdisciplinary and large-scale impacts are poorly understood. In WHIRLS we will use a synergistic and interdisciplinary approach to study fine-scale processes across a continuum of scales (1–100 km) and assess their impacts on air-sea exchange and marine biogeochemistry and biodiversity. We focus on the Agulhas Current System around South Africa because it is a global hotspot of eddy activity, ocean-atmosphere heat exchange, and marine productivity and diversity It is also a region that plays a key role for the global ocean circulation and global climate and climate change. We will use multiple coordinated observing strategies, including research vessels and a large ensemble of autonomous platforms, to collect physical, chemical, and biological datasets across scales. These data will be supplemented by high-resolution models of the ocean and the atmosphere, developed with a focus on the Agulhas Current System, as well as the latest data science methodologies. WHIRLS will improve the understanding of fine-scale processes and its representation in future earth system models for better predictions and projections of the future climate.