# Presentation: 948072

## 
Lynn K. Shay1, J. Martinez-Pedraja1, M. Powell2, B. Haus1, and J. Brewster1

1Division of Meteorology and Physical Oceanography, RSMAS
2Hurricane Research Division, AOML-NOAA 

ONR/ State of Florida/ NOAA Sea Grant
To improve our understanding of surface processes and their linkages to atmospheric and oceanic boundary layer processes in the coastal ocean.
 http://isotherm.rsmas.miami.edu/~nick

Lucy Wyatt, Mei Wang, Klaus-Werner Gurgel

**Lynn K. Shay****1****, J. Martinez-Pedraja****1****, M. Powell****2****, B. Haus****1****, and J. Brewster****1**
*1**Division of Meteorology and Physical Oceanography, RSMAS*
*2**Hurricane Research Division, AOML-NOAA*
***ONR/ State of Florida/ NOAA Sea Grant***
***To improve our understanding of surface processes and their linkages to atmospheric and oceanic boundary layer processes in the coastal ocean.***
*** ***_***http://isotherm.rsmas.miami.edu/~nick***_
***Lucy Wyatt, Mei Wang, Klaus-Werner Gurgel***

***Coastal Ocean Observing Systems: Oceanic Current and Wave Response to Hurricane Jeanne Detected by Wellen Radars***

## SEA-COOS (SECOORA): HF Radar

- WERA deployed 28 July-4 Oct 2003 in Venice Beach FL, and Bradenton Beach FL in support of SEA-COOS.
- Transmit frequency of 16.045 MHz, bandwidth of 200 KHz (` 1 km resolution).
- Tested different sample intervals-since WERA is FMCW system (512, 1024, 2048...) represented 2.2, 4.4, 9 min... samples.
- Ranges approached 100 km about 50% of the time.
- Comparisons to moored ADCP (COMPS), drifters and DBI Radar flights from NOAA P-3.

## Introduction:

- During 2004/2005 hurricane seasons, several (intense) hurricane landfalls in Florida.
- Most intense (cat 3 or above) hurricanes in the Atlantic basin occur in Gulf and Southeastern US (i.e. ***GCOOS and SECOORA***).
- An **Ocean Observing System** could provide valuable current, wave and wind data in improving and evaluating predictive models for landfalling hurricane scenarios.
- _HF radar provide one such tool in real-time mapping currents, winds and waves._
- WEllen RAdars (WERA) in **phased array** mode with cells of about 1 km over a range of ~80 to 90 km **(Research Phase). Monitoring Phase** provides hourly currents at 2 km intervals. These radar are (will be) deployed at Key Largo, Key Biscayne, (_Ft. Lauderdale,  Virgina Key)._
*Mapping currents, waves and wind directions during **Hurricane **Jeanne (04)**.*

## Radar Power (Doppler) Spectrum: Bragg Backscatter (Neptune Radar Ltd, Pisces)

- Wind (short wave) direction measured from magnitude difference between the two blue peaks. Here wind is blowing towards the radar.
- Hs can be derived from scaled ratio of 2nd -order to 1st-order peaks from a single
- radar site.
- Full directional** **spectra obtained from Iterative inversion of Doppler spectra to match surface
- Wave spectrum. Doppler spectra must be
- observed from two overlapping stations (Wyatt 1990)

## Surface Current Response to Hurricane Jeanne: 

## Current Resolution (cm s-1)

**WERA System / Crandon Park    ****→**

## Angles and GDOP (Chapman et al. 1998) and Accuracy Based on SNR (Gurgel, 2005)

## Performance and Measurement Grid

**Frances and Wilma-Longest Down Time    -        Domain and Distribution of Good Data**

## WERA Experimental Design: WFS/EFS

- WERA deployed 28 July-4 Oct 2003 in Venice Beach FL, and Bradenton Beach FL in support of SEA-COOS.
- Transmit frequency of 16.045 MHz, bandwidth of 200 KHz (~1 km resolution).
- Tested different sample intervals-since WERA is FMCW system (512, 1024, 2048...) represented 2.2, 4.4, 9 min... samples.
- Ranges approach 100 km about 50% of the time.
- _Real Time WERAs_ in KL, KB started in May 04-Almost 4 years of continuous data!
- Mini-Waves Experiment to test wave spectral
-     algorithms.

## WERA (blue) and 14-m (black)ADCP Record: Submesoscale Event 2Dec 04 – Feb 05

## Current &Current Acceleration (x 104 cm s-2).

**Current &Current Acceleration (x 10****4**** cm s****-2****).**

## Mini-Waves Experiment, Spring 2005.

- Fowey CMAN

## Directional Wave Spectra During Jeanne (04)

##         Wind Directions and Wind Speed Comparisons at Fowey  

**                         ****Rocks During Jeanne:24-25 Sept 2004**

-                   Wind Speeds

-                 Wind Directions

## Estimation of Cd at Fowey Rocks CMAN Stations 

**Following Jarosz (Science, 2007) **

- where *ρ* is a reference density (1025 kg m), * f* is the Coriolis parameter,  *U* and *V* are the depth-integrated along-shelf and cross-shelf velocity components, *H* is the water depth, *r *is a constant resistance coefficient at the sea floor, and *τ**sx *is the cross-shelf wind stress.

- Note the wind stress (*τ**sx* in (1)) is  defined  as :

- where *W**x* is the cross-shelf wind velocity component following Jarosz et al. (2006) using the Ivan data.

## Summary of Progress from ~4 Years of Measurements:

- EFS Deployment sensing ~100 km about 50% of the time, 80 km more than 80% of the time.
- Radar sites must be hardened to withstand severe hurricane conditions (i.e. GCOOS and SECOORA) with its power (generators) and built-in redundancy (Stakeholders!).
- State funding extends the footprint northward using 12.5 MHz transmit frequency system would yield 120 km-past Bimini:
- Provide high-res surface current and wave data for the US Navy’s Acoustic Observatory;
- Assess interoperability issues by sensing a domain  with a 25 MHz Sea Sonde.
***Central to the design/implementation of a National Network of HF Radars and an IOOS.***
- Improve Hs and directional wave spectra algorithms (compare to wave buoy measurements).
- Linkages to marine surface winds and waves (momentum fluxes).
***Wind-driven current response forces ***water toward the coast during hurricane landfall
- which causes the water to rise (i.e. surge). _Opportunity to assess surge models._