Remotely-Operated Surface Samplers for quantifying near-surface 3D stratified turbulent dynamics and heat fluxes in the Beaufort or Chukchi Seas
Abstract
The heat budget of the upper Arctic Ocean is both crucially imortant and highly unusual: temperature often increases with depth below the surface, and upward turbuletn heat fluxes through the top 20 meters can be as large as incoming heat fluxes from the sun. The heat budget of the upper Arctic Ocean is both crucially important and highly unusual: temperature often increases with depth below the surface, and upward turbulent heat fluxes through the top 20 meters can be as large as incoming heat fluxes from the sun. Freshwater input to the Arctic (from river and ice-?melt) is significant, leading to high near-?surface stratification, even in the presence of strong wind/wave-?forced turbulence. The stratified turbulence through this top-? most layer is the gate-?keeping link between the atmosphere/ice above and the deeper ocean below; its strength is set by a complex interplay between small-?scale horizontal processes (which create stratification by transporting buoyant fluid laterally) & turbulent processes (that diffuse it vertically). The sub-?mesoscale instabilities that often control both the lateral and vertical turbulent fluxes in this upper layer are challenging to measure with traditional ships or gliders, due to their fast time evolution and small horizontal scales. Here we propose to use two Remotely Operated Surface Samplers (ROSSs) to complement measurements from a traditional research vessel. ROSS is a seaworthy, open-?ocean autonomous vehicle that carries out precision-?navigated missions to gather transects of velocity, density and turbulence, with an emphasis on the upper 0-?20 meters of the water column. ROSS complements traditional shipboard sampling by providing a comprehensive 3D perspective of near-?surface processes at high vertical and horizontal resolution, controlled on-?the-?fly from the mother ship. The combination of such small-?scale synoptic measurements will uniquely allow us to 1) map out heat and fresh-?water patterns near the small-?scale fronts where diapycnal fluxes are intensified; 2) identify ‘smoking gun’ signatures of particular dynamical instabilities (in vorticity, for example) that are impossible without multiple synchronized platforms, and 3) quantify the resultant heat/mass/ momentum transports near the ocean’s upper boundary.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Nov 23, 2016
- Source ID
- N000141612574
Entities
People
- Jonathan D. Nash
Organizations
- Office of Naval Research
- Oregon State University
- United States Navy