Biophysical Submesoscale Processes in the Wake of Hurricane Ivan: Simulations and Satellite Observations

Abstract

Tropical cyclone induced phytoplankton productivity is examined using a tropical cyclone version of the Coupled Ocean/Atmosphere Mesoscale Prediction System (COAMPS®). A four-component Nutrient-Phytoplankton-Detritus biological model is integrated into COAMPS to create a fully integrated air-ocean-wave-biology model. This study investigates the upper ocean physical and biological states before and after Hurricane Ivan traversed the central Gulf of Mexico, in mid-September 2004. Elevated concentrations of surface chlorophyll-a appear in the simulation two days after the passage of the tropical cyclone, and these results are spatially and temporally coherent with Moderate Resolution Imaging Spectroradiometer (MODIS) satellite data for this time period. Model results reveal enhancement of chlorophyll-a in submesoscale filaments on the periphery of a warm-core eddy that are dominated by large values of lateral strain and relative vorticity at the surface. The vertical circulation of the filament, with its associated upward vertical motion, permits surface ventilation of cold, nitrogen-rich water and subsequent stimulation of primary biological production. Here, we show for the first time that coupled biological-physical submesoscale processes may be simulated via a fully integrated air-sea-wave-biology tropical cyclone model that provides a mechanistic explanation of the conspicuous features revealed in satellite ocean color imagery following Ivan.

Response of phytoplankton functional types to Hurricane Fabian (2003) in the Sargasso Sea

“…However, it fails to capture the moderate responses in the upper ocean. Although the horizontal resolution of the model captures mesoscale features such as eddies and fronts, TCs affect the physical ocean dynamics and the phytoplankton productivity at submesoscale (Smith et al 2019, Whitt et al 2019. The Darwin v0.2 cs510 dataset analysed here is derived from the global configuration of the MIT marine ecosystem model.…”

Assessing the Impact of Tides and Atmospheric Fronts on Submesoscale Physical and Bio-Optical Distributions near a Coastal Convergence Zone

“…High-resolution (50 m) 3-dimensional hydrodynamic model simulations were performed to provide a dynamical understanding of the coastal frontal processes, and to help us better understand the processes driving the bio-optical distributions, by separating the effects of tides and atmospheric forcing on the bio-optical property distributions. The Coupled Ocean/Atmosphere Mesoscale Prediction System (COAMPS) couples an atmospheric model with hydrodynamic and wave models to make both mesoscale and microscale predictions of the atmosphere and ocean [22][23][24]26]. COAMPS includes a globally relocatable grid, user-defined grid resolutions and dimensions, nested grids, and an option for idealized or real-time simulations.…”

Floating Debris in the Northern Gulf of Mexico after Hurricane Katrina

“…Such a data gap is primarily due to technical challenge in assessing marine debris in a timely manner before they dissipate and sink to the ocean floor . In contrast, the impact of Katrina and other hurricanes on the ocean’s bio-optical properties in the northern GoM has been well documented − as the remote sensing technology in assessing these properties is rather mature.…”