Compounding impact of severe weather events fuels marine heatwave in the coastal ocean

August 11, 2020

NGI Researchers B. Dzwonkowski, J. Coogan, S. Fournier, G. Lockridge, K. Park & T. Lee, from the University of South Alabama and Dauphin Island Sea Lab published an article titled "Compounding impact of severe weather events fuels marine heatwave in the coastal ocean" in "Nature Communications".

Exposure to extreme events is a major concern in coastal regions where growing human populations and stressed natural ecosystems are at significant risk to such phenomena. However, the complex sequence of processes that transform an event from notable to extreme can be challenging to identify and hence, limit forecast abilities. Here, we show an extreme heat content event (i.e., a marine heatwave) in coastal waters of the northern Gulf of Mexico resulted from compounding effects of a tropical storm followed by an atmospheric heatwave. This newly identified process of generating extreme ocean temperatures occurred prior to landfall of Hurricane Michael during October of 2018 and, as critical contributor to storm intensity, likely contributed to the subsequent extreme hurricane. This pattern of compounding processes will also exacerbate other environmental problems in temperaturesensitive ecosystems (e.g., coral bleaching, hypoxia) and is expected to have expanding impacts under global warming predictions.

This work has been particularly relevant to the last two hurricanes (Laura and Sally) that impacted the Gulf coast in 2020