4-d coastal ocean dynamics detected by surface current radar and auvs

4-D COASTAL OCEAN DYNAMICS DETECTED BY SURFACE CURRENT

RADAR AND AUVsL. K. Shay

Meteorology and Physical Oceanography University of Miami

P. Edgar AnOcean Engineering

Florida Atlantic University

SCIENTIFIC GOAL:

To provide a first-order description of complex oceanic flows and their relationship to surface processes in the littoral ocean subjected to tidal currents, western boundary currents, topographical changes and surface winds.

RESEARCH SUPPORTED BY ONR.

LITTORAL ZONE Complex Coastal Processes. 2-D/ 3-D Flow Fields. Boundary Current & Topography. Waves & Boundary Layer Winds. Impact: Civilian and US Navy Needs. Radar/AUV/Mooring/Ship-based

Approach. Applicable to Any Theater.

ONR CURRENT EFFORTS NICOP Results (AUV-based

Sampling). COPE 1,3 (HF-Radar Sampling). SFOMC (AUV/VHF-Radar/Mooring-

based Sampling Strategy). Planned:Longer Range AUV.

VHF RADAR Phased Array 32 Elements. Electronic Beam Forming. 700 Cells (250 m resolution). 60 km Square Domain. 20 Minute Sample Cycle. Theoretical Limit 11 km. Spectra and Currents.

ENGINEERINGOBJECTIVES:

Design/Implement Multiple ADCPs as Part of AUV Payload.

Evaluate Side-Looking Beam Orientations.

Map Currents Relate To Surface Dynamics.

Train Next Generation Graduate Students (i.e. Tactical Oceanography)

SCIENCE OBJECTIVES: Coherent Structures (Vortices, Fronts) Isolate BC and Tidal Flows/Forcing of

Iws At Shelf Break. Expand IWs Into Baroclinic Modes. Determine Wavenumber Spectra. Assess Boundary Layer Processes

During Storm and Quiescent Periods.

EXPERIMENTALDESIGN

VHF Mode of OSCR (7x9 km: 250 m Cell Spacing).

Ship-Based CTD/ADCP (2x2 km) 4-AUV Sampling Patterns (0.5-1km). Cyclesonde. NOVA/USF Moorings. NAVY ADCPs.

Experimental Domain

Experimental Domain

Sub-Mesoscale Vortex

Vortex Propagation

Surface Current RegimesStrong Florida Current Lobe

Structure

AUV MISSIONS Mixed Layer:

(Current and Turbulence)

Tidal Current: Bottom Boundary: Turbulence: Planned Adverse

Weather:

6 and 12-hr repeated grids : 500 m x 500 m.

15-26 hr: 1km x 1km 7 hr: 1 km x .500 km 4-6 hr: 1 km Xsects 12 hr : 500 m x 500 m

(March-April 00)

Ocean Explorer AUV

AUV Section

AUV Maps

Ship ADCP Transect

ANALYSIS &MODELING

Tidal Height and Current Analysis

Subinertial Flows and Vorticity (CTD)

Near-Inertial Waves (27.4 h )/Winds

IWs (k,l,m,w space) Mixed Layer Flows

(Langmuir Cells)

Grided Obs Initial Conditions for

LES Model Subgrid (<1 Km)

Parameterizations Compare Obs to

Simulations Optimize Adaptive

AUV-Sample Strategy

Ship ADCP/AUV and OSCR Comparison

Mooring Comparison

TIDAL PROCESSES Real Time Tidal Analyses After 7 Days. Sea-Level Variations (Continuity). Prediction versus Analysis (M2 , K1,). Operations: Tidal Prediction (i.e.

Chesapeake Bay). Vertical Structure. AUV Sampling of Surface Current

Signatures.

Tidal Ellipses at Cope

SFTF APPLICATIONS US Navy Coastal Surveys. METOC (JTFX) Operations. Ship-based Operations In Differing

Venues/Theaters. Coupling With Models (i.e. LES). Provides Environmental Data To

Assess Impact on Fleet Operations.

SUMMARY Synergistic Approach: Synoptic

Variability. Fine-Scale to Submesoscale Processes. 2-D/3-D Variability not Mean. Real Time: JTFX (Ships,Aircraft,AUV). Improve Predictive Capability At Navy

Centers. Train Next-Generation Students.