Measured and Modelled Wave Climates of South-Eastern Australia

Transcription

1 Measured and Modelled Wave Climates of South-Eastern Australia Ian Coghlan & Bill Peirson WRL, UNSW Russel Morison & Michael Banner Maths, UNSW The University of New South Wales, Sydney, 2052.

2 Wave Measurement Records 18 long term datasets recorded in 15 to 100 m water depth from around the Australian coastline.

3 Queensland

4 New South Wales

5 Victoria

6 Tasmania

7 South Australia

8 Western Australia

9 Northern Territory

10 Wave Measurement Records 18 long term datasets recorded in 15 to 100 m water depth from around the Australian coastline.

11 National Wave Climatology Mean H S (m) over all NWW3 data Hemer et al 2007 A tongue of increased H S was observed extending into the Tasman Sea for all of the datasets examined The maximum of this tongue is located 2/3 rds the way from the NSW coast to New Zealand

12 NSW Wave Buoy Statistics H S (m) Statistics (Shand et al, 2010) Location Mean Median 10% Exc. 1% Exc. Max. Location Depth (m) Distance Offshore (km) Capture Rate (%) Length ( years) Byron Bay Byron Bay Coffs Harbour Coffs Harbour Crowdy Head Crowdy Head Sydney Sydney Port Kembla Port Kembla Batemans Bay Batemans Bay Eden Eden

13 Web-Marvl:

14 WAVEWATCH III 2009 National Weather Service (NWS), National Oceanic and Atmospheric Administration, all rights reserved. WAVEWATCH III is a trademark of the NWS. No unauthorized use without permission. N t + x cσ N cθ N Stot [( c + U ) N ] + + = N = E( σ, θ ) g σ θ σ, σ S tot = S in + S wc + S nl 4 + S bot + S brk + S nl3 + S xx NCEP / NWS supported Community model: Current Release version 4.18 New grids, new numeric, new physics Improved computer performance, Improved MPI Performance. 2 way nested rectangular grids, curvilinear grids, (lambert conformal, polar stereographic etc) and unstructured grids (triangular grids). New Physics packages, new Sin, Snl, and Sds source terms available.

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21 WaveWatch III Pacific Ocean Domain

22 SE Australia Domain

23 Sydney Buoy: Significant Wave Height

24 Sydney Buoy : Peak Period

25 Coffs Harbour Significant Wave height

26 Coffs Harbour Peak Period

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30 SWAN SWAN is a third-generation wave model, developed at Delft University of Technology, that computes random, short-crested wind-generated waves in coastal regions and inland waters SWAN accounts for the following physics: Wave propagation in time and space, shoaling, refraction due to current and depth, frequency shifting due to currents and non-stationary depth. Wave generation by wind. Three- and four-wave interactions. Whitecapping, bottom friction and depth-induced breaking. Dissipation due to aquatic vegetation, turbulent flow and viscous fluid mud. Wave-induced set-up. Diffraction Propagation from laboratory up to global scales. Transmission through and reflection (specular and diffuse) against obstacles.

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32 Swan Bathymetry: 2 domains

33 SWAN Model Parameters

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35 Bathymetry: MARVL.vs. OEH

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38 Swan : Time series: Marvl & OEH

39 Sydney Buoy: Swan: MARVL- NCEP winds Significant Wave Height Time Series

40 Sydney Buoy: Swan OEH Significant Wave Height Time Series

41 Sydney Buoy: SWAN-MARVL-ACCESS Modelled.vs. Observed Wave Height

42 Sydney Buoy: SWAN-MARVL-NCEP Modelled.vs. Observed Wave Height

43 Sydney Buoy: SWAN-OEH Modelled.vs. Observed Wave Height

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45 Coffs Harbour buoy: SWAN-MARVL-ACCESS Significant Wave Height Time Series

46 Coffs Harbour buoy: SWAN-MARVL-NCEP Significant Wave Height Time Series

47 Coffs Harbour buoy: SWAN-OEH Significant Wave Height Time Series

48 Coffs Harbour buoy: HF-RADAR Significant Wave Height Time Series

49 Coffs SWAN MARVL (ACCESS / NCEP) Observed.vs. Modelled Wave Height

50 Coffs SWAN-OEH / HF-RADAR Observed.vs. Modelled Wave Height

51 Coffs Harbour BIAS / RMSE.vs. Height

52 Conclusions. Not Enough Wave Data collected in Australian waters. No national buoy storage facility: (IMOS?) Web_Marvl : great new way of helping researchers get the data to run models. Still need to know what you are doing. SWAN & WWIII available in Web Marvl. SWAN & WWIII source codes freely available. Both do well forecasting waves, and work best combined when looking in shallow coastal zones.