Deep surface mixing events in the Nordic Seas: The roles of coupled wind and surface wave forcing
Abstract
Mixing in the ocean surface boundary layer (OBL) is forced by a combination of convection from surface cooling, wind produced curren t shear, and interaction of current shear with propagating surface waves (breaking and Langmuir circulation). These three processes generate turbulence that is generally a maximum in strength at the surface and decreases with depth until reaching the pycnocline, where stratification inhibits further downward OBL growth through entrainment mixing. The goal of this research is to develop a bet ter understand the process whereby surface forced turbulence leads to rapid mixed layer deepening events. Our research will determin e how surface forcing translates into entrainment at the mixed layer base, generation of shear in the pycnocline, and changes in the overall density structure of the upper ocean. Our objectives are to: 1) understand the processes that result in deep mixing event s in response to resonant winds and surface waves, 2) quantify the degree of coupling between atmospheric cyclone development or pro pagation and deep mixing events, 3) identify the main turbulence production terms (e.g. shear production, turbulence transport) that generate strong entrainment mixing at the OBL base and how they are related to surface forcing and, 4) examine how ocean mixing par ameterizations perform under conditions with strong surface forcing.These objectives will be met by conducting case studies based on field expeditions that are part of this DRI. We will apply an ocean large-eddy simulation model for direct comparison with fine st ructure measurements from ship, buoy and autonomous instruments (e.g. gliders, floats) using measured flux and wave data.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Sep 08, 2021
- Source ID
- N000142112740
Entities
People
- Eric Skyllingstad
Organizations
- Office of Naval Research
- Oregon State University
- United States Navy