Sack Lunch Seminar (SLS)

A dynamical mechanism for ocean ecosystem refuge amidst tropical warming

Global climate models predict a weakening of the atmospheric overturning circulation in response to rising levels of atmospheric CO2. In the tropical Pacific, where the atmosphere and ocean are tightly coupled, a weakening of the trade winds would result in reduced equatorial upwelling and hence a decline in primary productivity and an additional warming component superimposed on the global mean trend. Both of these regional changes pose direct threats to marine ecosystems. In most cases, however, global climate models do not simulate the interaction of islands and atolls with the mean ocean circulation and therefore do not consider their impact on SST and biomass distribution. By combining high-resolution satellite measurements, an ensemble of global climate models, and an eddy-resolving regional ocean circulation model, we investigate a possible mechanism for the mitigation of warming and reduced nutrient supply due to forced changes in large-scale ocean circulation.