Modeling, Predictions and Adaptive Sampling Team HARVARD - MIT Modeling, Predictions and Adaptive Sampling Team Pierre Lermusiaux, Patrick Haley, Ding Wang (MIT), Wayne Leslie and Oleg Logutov Ocean and Acoustic Modeling and Predictions Adaptive Sampling Recommendations PLUSNet Hot Wash-up Presentation MBARI, Aug 26, 2006

Daily Environmental Prediction “Undersea Weather” Major Accomplishment I 6 4 OPAREA Bathymetry and Analysis Radials Measured and Estimated Sound Speed Radial 4 Measured and Estimated Averaged Currents 0-200m The plots corresponds to Aug 18, 12Z. Bottom left and middle plots: Notice the small upwelling crossing the PLUSNet Oparea (lower sound speeds in surface originating from the coastline, south of AN). At that time, currents in the PLUSNet domain were relatively weak, to the south-southeast. Right, top and bottom plots: Offshore, notice the piece (1 quadrant) of a large anticylonic eddy, which influences the PLUSNet area at the larger-scales Surface SSP and Currents 30m Depth SSP and Currents 100m Depth SSP and Currents See: http://ocean.deas.harvard.edu/PLUSNet for twice daily plots and hourly data files

Daily Acoustic-Environment Predictions e.g: Aug 23 4PM Local Time (Aug 24 00Z) Major Accomplishment II 6 4 OPAREA Bathymetry and Analysis Radials Forecast Surface Currents (used by PLUSNet assets for planning drifting missions) Surface SSP and Currents Top Row: Forecast currents and vertically averaged currents for Aug 23, 4PM. They are used by PLUSNet assets for guidance in planning their missions. Notice the upwelling presently going on, which affects the PLUSNet ops. Bottom row: Coupled predictions of ocean environment and acoustic propagation conditions (transmission loss curves) issued in real-time. This is the first time this has been done. They are usefully accurate according to Warren Fox. Bottom left: Notice the impact of the strengthening upwelling conditions (cooling in surface and rise of cold waters from the deeper ocean) Bottom right: Upwelling conditions modifies acoustic propagation and transmission loss curves (various TL curves are time-lagged by 2 hours, showing uncertainties) Transmission Loss Prediction (issued on Aug 22 12Z) Along Radial 6, for a source at 5m and a receiver at 15, 45 and 75m Sound Speed Radial 6 See: http://ocean.deas.harvard.edu/PLUSNet for twice daily plots and hourly data files

Example of Daily Summary Description Emails Environmental and acoustic nowcasts and predictions up to 00Z Aug 26 are available from: http://oceans.deas.harvard.edu/PLUSNet http://oceans.deas.harvard.edu/PLUSNet/Aug25/plusnet_product.html Product files are in: http://oceans.deas.harvard.edu/PLUSNet/Products Upwelling event is ending and our forecasts indicate that relaxation conditions (warmer surface temperatures and no wind-driven currents) will start tomorrow. See for example tomorrow's afternoon surface sound speed and current vectors: http://oceans.deas.harvard.edu/PLUSNet/Aug25/PN/Forecast/ssp000_aug27_fcst_00Z_PN.gif Based on our studies of the past week of transmission loss estimates, relaxation conditions correspond to -more- mean loss at 100Hz and 400Hz than upwelling conditions. The average difference at 100-400Hz and at 10km range is about 3 to 8db more mean loss. It would be very interesting to find out if the measured mean acoustic performance (TL)at these frequencies over 7 to 15km ranges is lower tomorrow afternoon than it has been in the past days of upwelling conditions. Vertically averaged current velocities in the PLUSNet ops area are expected to be to the northwest, following the coastline. For example, for tomorrow morning: http://oceans.deas.harvard.edu/PLUSNet/Aug25/PN/Forecast/vave_PN_aug26_fcst_12Z.gif Surface velocities are expected to be patchy. For drifting behaviors, we recommend to combine it with a vertical yoyo so as to be drifting in vertically averaged currents, which are forecast to the northwest. Transmission loss predictions available from: http://oceans.deas.harvard.edu/PLUSNet/Prolog/Aug25/index.html

Effects of the predictable ocean environment on acoustic TL predictions Relaxation: B6 D3 8_25_06 Upwelling: B6 D1 8_22_06 Relaxation conditions (warmer surface temperatures and no wind-driven currents) correspond to more mean loss at 100Hz and 400Hz than upwelling conditions: 3 to 8db more mean loss over 7 to 15km.

Example of AREA mission C2 Major Accomplishment III Adaptive Yoyo Major Accomplishment III 8/22/06 Starting point: lat=36.9414, long=-122.2232 1. Bearing=180 degree clockwise from the north, waypoints are: r: 0 1 2 3 4 5 6 7 8 9 10 km z: 0 50 75.0000 75.0000 100.0000 50.0000 0 50.0000 0 50.0000 100.0000 m 2. Bearing=180 degree clockwise from the north, max range=10km, optimal yoyo control parameters are(10, 0.5): XXX.Initialize(5, 100, 0, 10, 0.5)//upper bound: 5m; lower bound: 100m; initial depth: 0m; points:10; threshold: 0.5. 3. Bearing=180 degree clockwise from the north ADP<double> DW_ADP; DW_ADP.Initialize();

A priori Mean TL std Posteriori Mean TL std

Example of AREA mission C4 Major Accomplishment III Front Tracking Major Accomplishment III 8/23/06 In the morning: 1. run predetermined path: Waypoints are: (lat=36.916774452289 long=-122.190015784337), (36.959751554578  -122.262152715663), (36.966729966627, -122.255703125301),(36.923748958313 , -122.183563374699), depth=0m 2. or run this: Starting point: lat= 36.916774452289  , long =-122.190015784337, depth=0m.   DingWang_2D_Gradient<double> DW_Gradient;   DW_Gradient.Initialize(270., -1);//the initial AUV direction is 270 degree clockwise from the north; -1: follow the opposite gradient direction let AUV hit the northwest side of PLUSNet box, and then directly come back. In the afternoon: 3. Waypoints are: (36.927933661928  -122.179691928916), (36.970917013855, -122.251833371084), (36.977895425904,  -122.245383780723), (36.934908167952 -122.173239519277), depth=0m. 4. Starting point: lat= 36.927933661928  , long = -122.179691928916, depth=0m. DingWang_2D_Gradient<double> DW_Gradient;   DW_Gradient.Initialize(306.663991., -1);//the initial AUV direction is 306 degree clockwise from the north; -1: follow the opposite gradient direction let AUV hit the northwest side of PLUSNet box, and then directly come back.

w w 8_24_06 Morning 8_24_06 Afternoon 8_24_06 Morning

Significant Lessons learned And Data Needs Feedback during the telecon was essential Enjoyed feedback very much. Thank you PLUSNet team!! Next time, we could create a coop plusnet web-page where such feedback can be posted Data that you have and data that you need Have: substantial measured T,S data and data-driven model estimates Need: More plots or Quantitative evidence to support successful or failed usage of our estimates, e.g: Marc Stewart’s email based on our SE currents predictions in S corner of domain : “Pierre, You'll be interested to know that our Restech reported substantial SE surface current in the S corner of the PLUSNet box today as she attempted to recover a Bluefin in an Avon. I personally doubted it, but now I know better! Thanks, Marc”