Emulating probabilities of coral reef bleaching and mortality using a coupled model framework

Corinne Hartin1, Abigail Snyder2, Stephanie Pennington3, Kalyn Dorheim4, Jonathan Huster5 and Matthew Binsted1, (1)Joint Global Change Research Institute, College Park, United States, (2)Joint Global Change Research Institute, College Park, MD, United States, (3)Pacific Northwest National Laboratory, Joint Global Change Research Institute, College Park, MD, United States, (4)Pacific Northwest National Laboratory, Joint Global Change Research Institute, Richland, WA, United States, (5)Pacific Northwest National Laboratory, Richland, United States
Abstract:
In this study we explore the probabilities of coral reef bleaching and mortality along the Florida reef track, Hawaii, and the Caribbean under a range of emission scenarios consistent with the Nationally Determined Contributions. Using a reduced-form climate model, Hector, in combination with a spatially resolving climate emulator, we emulate atmospheric temperature and sea-surface temperature from a suite of CMIP5 and CMIP6 models. This information is used to drive the Coral Mortality and Bleaching Output mode (COMBO). COMBO integrates the impacts of future climate change, both thermal and ocean chemistry, on coral growth and mortality to estimate changes in coral cover with time. We simulate up to 3 episodic bleaching events, each with an increasing sea surface temperature thresholds under 3 different aragonite saturation sensitivities to investigate which emission pathway reduces the probability of bleaching and mortality across the range of CMIP models considered.