Simulated ocean surface boundary layer turbulence under Hurricane Irene (~9:30 UTC, August 28, 2011) entrains cold bottom water that cools the sea surface and weakens the hurricane as it makes landfall on the New Jersey continental shelf.
Large-aspect-ratio coherent structures that modify the evolution of the mean sea-surface temperature are highlighted in a 2 km by 2 km by 35 m deep domain.
These large structures, which are neither well-observed nor explicitly accounted for in typical ocean models, modestly but systematically alter the vertical fluxes of momentum and temperature under the storm. Hence, forecast models of sea-surface temperature change under a hurricane may require new observations and parameterizations of ocean turbulence that explicitly address the large-aspect-ratio structures.
As the hurricane approaches and the wind intensifies, the ocean surface current (orange) organizes into streaks along the wind direction. About 10 m below the surface, intermittent billows perturb the temperature interface (blue-gray) and drive exchange between the warm surface and cold bottom waters on the Mid-Atlantic Bight.
Daniel Whitt (NCAR/CGD) and Clifford Watkins (Rutgers University)
CISL Project Number: NCGD0038
CISL Project Dates: November 1, 2017 - October 31, 2018
Project Lead: Daniel Whitt
Project Title: Modeling impacts of winds on ocean submesoscales and mixed layer dynamics
Cheyenne: 10,600,000 core-hours
DIABLO large eddy simulation
Taylor, J. R. (2008). Numerical simulations of the stratified oceanic bottom boundary layer.
San Diego, CA, USA: University of California.
The simulation data were generated using the DIABLO Navier Stokes simulator with an LES closure by Daniel Whitt.
Matt Rehme (NCAR/CISL)
Imagery produced by VAPOR, a product of the Computational Information Systems Laboratory at the National Center for Atmospheric Research.
Watkins, C., and D. B. Whitt, Large-aspect-ratio structures in simulated ocean surface boundary layer turbulence under a hurricane. Journal of Physical Oceanography, doi: https://doi.org/10.1175/JPO-D-20-0134.1.
Related data can be obtained at https://doi.org/10.6084/m9.figshare.12486056.v5 or by contacting the authors of the paper.
The National Center for Atmospheric Research is sponsored by the National Science Foundation. Any opinions, findings and conclusions or recommendations expressed in this material do not necessarily reflect the views of the National Science Foundation.
