Forecasting Wind Setup in a Coastal Estuary Presenter: Jeff Colvin Steven Lazarus, Michael Splitt, Bryan Holman Robert Weaver, Peyman Taeb, Atoosa Saberi Florida Institute of Technology 14 th Symposium on the Coastal Environment 96 th American Meteorological Society Annual Meeting

The Indian River Lagoon (IRL) 2 Banana River Mosquito Lagoon Indian River The Indian River Lagoon (IRL) is a long, narrow coastal estuary on Florida’s east coast (250 km long, less than 2 km in width in places) Wind Setup: Contributes to local flooding Contributes to local flooding Increases the base water level to which wave heights will be added (see Lazarus, Wed, 1:30pm) Increases the base water level to which wave heights will be added (see Lazarus, Wed, 1:30pm) Affects the transport of nutrients and sediments: Affects the transport of nutrients and sediments: Seagrass beds Seagrass beds Oyster habitats Oyster habitats Overall health of the lagoon system Overall health of the lagoon system Difficult to forecast - operational models do not adequately resolve the IRL (see Taeb, Thurs, 2:00pm) Difficult to forecast - operational models do not adequately resolve the IRL (see Taeb, Thurs, 2:00pm) 96 th American Meteorological Society Annual Meeting

The Indian River Lagoon (IRL) 3 Goals of this research / Outline of talk: Deploy sensors and collect water level data at various locations along the northern IRL. Deploy sensors and collect water level data at various locations along the northern IRL. Choose wind events to analyze – northerly or southerly lagoon-oriented winds greater than 7 m/s with a duration of at least 12 hours. Choose wind events to analyze – northerly or southerly lagoon-oriented winds greater than 7 m/s with a duration of at least 12 hours. Calculate the wind setup from water level data during these wind events. Calculate the wind setup from water level data during these wind events. Using the Zuider Zee equation as a starting point, determine an analytic solution to forecasting wind setup on the IRL. Using the Zuider Zee equation as a starting point, determine an analytic solution to forecasting wind setup on the IRL. 96 th American Meteorological Society Annual Meeting

4 Deploying Pressure Level Gauges Three HOBO titanium pressure sensors were deployed in the IRL Three HOBO titanium pressure sensors were deployed in the IRL Stilling wells were used to help filter out higher frequency waves Stilling wells were used to help filter out higher frequency waves The three locations were supplemented by two sensors from St. Johns River Water Management District, giving five total sensors along the northern IRL The three locations were supplemented by two sensors from St. Johns River Water Management District, giving five total sensors along the northern IRL 96 th American Meteorological Society Annual Meeting

5 Titusville Melbourne South Banana River The Northern IRL and Gauge Locations Pressure gauge locations Kars Park Fins Marina 96 th American Meteorological Society Annual Meeting

6 Water Level Data from Pressure Gauges Water levels are anomalies from the 5 month mean (Nov 2014 – Mar 2015) Water levels are anomalies from the 5 month mean (Nov 2014 – Mar 2015) During the dry season to minimize freshwater inflow to lagoon During the dry season to minimize freshwater inflow to lagoon Southernmost location (near Sebastian Inlet) shows a tidal signal Southernmost location (near Sebastian Inlet) shows a tidal signal 96 th American Meteorological Society Annual Meeting

7 Water Level Data from Pressure Gauges 12 hour moving average to smooth water level data 12 hour moving average to smooth water level data For the remainder of the talk, we will look only at the northern most and southern most points For the remainder of the talk, we will look only at the northern most and southern most points Titusville (red) and Fins Marina (purple) are 100 km apart Titusville (red) and Fins Marina (purple) are 100 km apart 96 th American Meteorological Society Annual Meeting

8 High Wind Events - Water Level Plots 96 th American Meteorological Society Annual Meeting

9 Forecasting Setup: Zuider Zee Equation Landsat photo S = setup U = wind speed F = fetch (<= distance between locations) D = depth (along fetch or mean reservoir?) Ijsselmeer 96 th American Meteorological Society Annual Meeting

10 Setup: Mean Wind and Fetch Setup: S (cm) Wind Speed: U (knots) Fetch: F (km) 96 th American Meteorological Society Annual Meeting

11 Setup: Peak Wind and Fetch Setup: S (cm) Wind Speed: U (knots) Fetch: F (km) 96 th American Meteorological Society Annual Meeting

12 Setup: Component Peak Wind and Fetch Setup: S (cm) Wind Speed: U (knots) Fetch: F (km) 96 th American Meteorological Society Annual Meeting

13 Mean versus Component Peak Winds 96 th American Meteorological Society Annual Meeting

14 Peak Wind Components & Water Levels 96 th American Meteorological Society Annual Meeting

15 Peak Wind Components & Water Levels 96 th American Meteorological Society Annual Meeting

16 Setup Response Time Performed cross correlation to determine the lag between peak wind occurrence and maximum wind setup Performed cross correlation to determine the lag between peak wind occurrence and maximum wind setup Correlation peak occurred around 5.5 hours Correlation peak occurred around 5.5 hours Helpful for forecasters to know that maximum setup in the IRL will occur about 5 or 6 hours after peak winds. Helpful for forecasters to know that maximum setup in the IRL will occur about 5 or 6 hours after peak winds. 96 th American Meteorological Society Annual Meeting

17 Reasonable Lag Time? 100 km Center of 50 km Center of km The center of mass would need to move 2083 m in 5 or 6 hours, giving a mean current in the IRL of between and m/s. 96 th American Meteorological Society Annual Meeting 1.35 m 1.05 m 1.2 m

18 Next Steps More events More events Add remaining sensors Add remaining sensors Does ADCIRC validate the flow rate needed for the calculated lag time? Does ADCIRC validate the flow rate needed for the calculated lag time? Use the Short Range Ensemble Forecast (SREF) for wind input to calculate a wind setup forecast (or trigger the NWS to allocate resources for a high res model run) Use the Short Range Ensemble Forecast (SREF) for wind input to calculate a wind setup forecast (or trigger the NWS to allocate resources for a high res model run) 96 th American Meteorological Society Annual Meeting

19 Thank You! Acknowledgements: This work was supported under NOAA CSTAR grant #NA14NWS Department of Marine and Environmental Systems Florida Institute of Technology 96 th American Meteorological Society Annual Meeting