Float Array for Submesoscales and Turbulence in ARCTERX
Abstract
Submesoscale (SMS) energy is elevated (a) on the peripheries of mesoscale features, (b) intopographic wakes, and (c) due to turbulen t thermal wind. In 2D quasigeostrophic flows, eddykinetic energy (EKE) cascades to larger scales as small eddies coalesce. In 3D age ostrophic flows,EKE cascades to smaller scales and is dissipated as turbulence. Both occur simultaneously. Herewe propose a profilin g float array for ARCTERX that contributes to quantifying downscale energycascades from the SMS flows to determine the relative impo rtance of internal gravity wave (IGW)and SMS currents in turbulence generation and to assess turbulence distributions in both time a ndspace, including the role that turbulence plays in vorticity evolution and vice versa.To sustain coverage over months across spati al scales ranging from mesoscale eddies ofO(200) km to turbulence of O(0.01-10) m, we will use an array of 15 existing SOLO-II profi lingfloats with CTDs and 8 Flippin Chi SOLO (FCS) floats fully instrumented with turbulencesensors and developed with ONR funding ( 2 exist, 6 to be constructed). This array will be deployedto attempt to quantify:1. the rate of the downscale cascade and mixing,2. turbulence generated by SMS currents in the interior, and3. coupling between SMS currents and IGWs.The float array will obtain the t ime-varying spatial structure of turbulence through and aroundan evolving SMS feature. Objective mapping of the measured density, te mperature, salinity, surfacevelocity and depth-mean velocity fields will extend our assessment to the time-varying spice, strain,vor ticity, and divergence fields.Specifically, we propose the following contributions.1. SIO will manufacture 6 new FCS floats with CTD s to which OSU will add an additionalpackage that includes 2 shear probes, 2 thermistors and pitot tube for sensing turbulence,press ure sensor, compass and 3-axis linear accelerometer package.2. 15 SOLO-II floats from FLEAT and CALYPSO are available for ARCTERX. T wo existingFCS floats built under ONR grant N00014-17-1-2700 require firmware upgrades for dataexfiltration. These floats have alrea dy been fabricated and are ready for use in ARCTERXwithout further fabrication cost.3. We will deploy 5 SOLO-II and 5 FCS floats flo ats in 2023 field experiment. We intend torecover all FCS floats in 2023.4. We will develop the necessary on-board processing to obv iate the need for recoveries.5. We will deploy 10 SOLO-II and 8 FCS floats in 2024 field experiment. No floats will berecovered. The se floats will be in the field for 3-12 months, depending on the mission.Budgets include construction costs of $223k (SIO) and $100k (OSU). These costs will beproposed to DURIP with the intent that they be subtracted from SIO and OSU ARCTERX budgets.Note: For clar ity OSU and SIO proposals are identical since they are interdependent. Tasks aredistinct and defined within. Budgets are separate.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Oct 22, 2021
- Source ID
- N000142112878
Entities
People
- James N. Moum
Organizations
- Office of Naval Research
- Oregon State University
- United States Navy