Understanding and Managing Harmful Algal Bloom in West Florida Shelf using E3SM Earth System Model

Abstract:

Harmful algal blooms (commonly known as red tide) along the West Florida Shelf (WFS) in the Gulf of Mexico are common and caused by the regular occurrence of the toxic Karenia brevis, a mixotrophic dinoflagellate. The Karenia brevis blooms can have significant environmental and socioeconomic impacts on coastal areas in Florida and worldwide as they can cause massive fish kills; render shellfish poisoning; harm birds, marine mammals, and sea turtles; affect human health causing respiratory, eye and skin irritation; impact tourism industry and recreational activities, among other economic impacts. While the growth and persistence of Karenia brevis depends on wind direction and strength, temperature, salinity, and nutrients, the exact natural factors and potential anthropogenic roles that result in Karenia brevis bloom outbreaks are not well understood. A current working hypothesis for the occurrence of Karina brevis bloom in WFS is based on the type and location of upwelling that is caused by Loop Current and its eddies. In this study we use the U.S. Department of Energy's Energy Exascale Earth System Model (E3SM) to simulate key variables that are required to detect Loop Current in WFS and analyze Karenia brevis bloom occurrence. E3SM is a state-of-the-art Earth system model that simulates the ocean system using the Model for Prediction Across Scales (MPAS), which interacts with the land, river, land ice and sea ice, and atmospheric model components of E3SM to simulate the Earth system. This study aims to establish correlation and history matching between Loop Current and Karenia brevis bloom distribution. This E3SM-based modeling framework has great management implications in forecasting Karenia brevis bloom distribution and assessing the impact of climate change on Karina brevis bloom occurrence.