En:1st nopp wave meeting


1st NOPP wave meeting, San Francisco July 2010

List of participants: tjanssen@sfsu.edu , fabrice.ardhuin@ifremer.fr, ffedele3@gtsav.gatech.edu, rogers@nrlssc.navy.mil, m.banner@unsw.edu.au, r.morison@unsw.edu.au, jhenrique@zeroii.com.au, ababanin@swin.edu.au ….

This meeting is not a conference like WISE or OMAE with a list of papers, but should really be a WORKshop. In order to start the debate and work we encourage participants to present a “position paper” reviewing the state of the art, this may be done in a collective fashion. Based on that some clear questions should arise, be debated and form the basis of our joint work for the coming months.

Obviously, it is also a good opportunity to present some recent results, but this should leave room for discussions and be streamlined toward integration in numerical wave models.

As a result the program lists the “position papers” in bold, that are expected to last 20 minutes or so and some shorter intervention meant to shed some light on specific sub-topics

1. Issues to be addressed

  • How much do we know the physics (going over the different source terms)
  • How do we verify the “know” bits and test ideas for unknown bits
    • Classical or near-classical tests: fetch-limited, PM limit, slanting fetch growth (with directional data), spectral shape (bimodality, lobe ratio) …
    • More elaborate data sets: breaking statistics, whitecap coverage …
    • Creative use of usual data: patterns of changes, analysis of normalized spectra, data mining for specific cases (swell-dominated, turning winds …)
  • Physics and numerics …: being careful, in particular for directional spectra
  • How do we work together as a group and towards operational implementation

2. Agenda for the 1st NOPP wave meeting

Tuesday 20

9:00 AM: Welcome (Linwood, Don, Hendrik)

9:15 AM: Status on operational systems or hindcasts and known errors

  • Hendrik Tolman: operational systems, needs, issues and performances
  • F. Ardhuin: analyzing forcing and parameterization errors from the SHOM-Ifremer system: among other issues, evidence for swell damping, iceberg effects, mixed sea-swell behaviour, extreme seas, swell patterns ….
  • E. Rogers: Higher order validation, identification and documentation of model deficiencies

11:00 AM: Wind input: General discussion about what we know and what we do not know. What is really known beyond Snyder et al?

  • Alex Babanin (with Erick Rogers if Erick agrees): new observational features of the wind-input and whitecap dissipation, their independent testing and calibration, implementation
  • Fabrice Ardhuin: Wind input and dissipation level constrained by slanting fetch growth

Noon: lunch break

1:00 PM: Discussion on the knowledge of physics in relation to features of spectral wave evolution

  • Don Resio and Andrei Pushkarev: Nonlinear interactions and spectral shape
  • Mike Banner: Wave dissipation: causes, effects and modeling
  • Russel Morison: Spectral shapes, high frequency spectral levels, bimodality, source term balances and constraints.
  • Alex Babanin: integral, spectral and directional dependences for wave evolution
  • Alex Babanin: wave breaking and dissipation
  • additional constraints :
    • Fabrice Ardhuin: analysis of mean square slopes and behaviour
    • Alex Babanin: constraints for the dissipation and input, their variability
    • others …

6:00 PM: Meeting adjourned

Wednesday 21

8:30 AM: Shallow water physics

  • Tim Janssen: Nonlinearity from deep to shallow: a discussion primer.
  • Tim Janssen and Andre van der Westhuysen :depth-induced breaking
  • Fabrice Ardhuin : combined deep and shallow breaking. bottom friction
  • Alex Sheremet: dissipation over mud

1:00 PM: validation datasets

  • Spectral shapes : how do we validate them.

The validation dataset: which data for which purpose ?

  • Francesco Fedele: Wave Acquisition Stereo System (WASS) data and frequency-wavenumber spectra of wind waves
  • Jeff Hanson: Duck shelf data and finite depth physics
  • Fabrice Ardhuin: SAR, buoy and seismometer data for the analysis of swell fields

Thursday 22

8:30 PM: Practical calculation of nonlinear interactions

  • Gerbrant van Vledder and Will Perrie and Hendrik Tolman (??): Present status on faster alternatives and trade-offs for better approximations than the DIA. (please guys organize yourselves …)

10:30 PM: Wave model numerics

  • Anybody willing to summarize the numerical schemes, limiters, directional renormalization, diffusion, splitting errors ?

Erick Rogers to begin, others to follow ?

1:00 PM: Practical aspects of joint work

  • Databases
  • Code version management

2. Publications relevant to our discussions

Please include below any useful references, possibly with http adresses for PDF or other materials

Wave breaking

  • Filipot, J.-F., F. Ardhuin, and A. Babanin, “A unified deep-to-shallow-water wave-breaking probability parameterization,” J. Geophys. Res., vol. 115, p. C04022, 2010.
  • Babanin, A.V., 2009: Breaking of ocean surface waves. Acta Physica Slovaca, 59(4), 305-535
  • Galchenko, A., A.V. Babanin, D. Chalikov, I.R. Young, and T.-W. Hsu, 2010: Modulation depth and breaking strength for deep-water wave groups. Journal of Physical Oceanography, in press
  • Babanin, A.V., D. Chalikov, I.R. Young, and I. Savelyev, 2010: Numerical and laboratory investigation of breaking of steep two-dimensional waves in deep water. Journal of Fluid Mechanics, 644, 433-463
  • Toffoli, A., A.V. Babanin, T. Waseda, and M. Onorato, 2010: The maximum steepness of oceanic waves. Geophysical Research Letters, 37, L05603, doi:10.1029/2009GL041771
  • Babanin, A.V., D. Chalikov, I.R. Young, and I. Savelyev, 2007: Predicting the breaking onset of surface water waves. Geophysical Research Letters, 34, L07605, doi:10.1029/2006GL029135

Swell dissipation

  • F. Ardhuin, B. Chapron, and F. Collard, “Observation of swell dissipation across oceans,” Geophys. Res. Lett., vol. 36, p. L06607, 2009.
  • F. Collard, F. Ardhuin, and B. Chapron, “Monitoring and analysis of ocean swell fields using a spaceborne SAR: a new method for routine observations,” J. Geophys. Res., vol. 114, p. C07023, 2009.

Source term balances

  • F. Ardhuin, E. Rogers, A. Babanin, J.-F. Filipot, R. Magne, A. Roland, A. van der Westhuysen, P. Queffeulou, J.-M. Lefevre, L. Aouf, and F. Collard, Semi-empirical dissipation source functions for wind-wave models: part I, definition, calibration and validation , J. Phys. Oceanogr., 40, corrected proofs, 2010.
  • Babanin, A.V., K.N. Tsagareli, I.R Young, and D.J. Walker, 2010 : Numerical investigation of spectral evolution of wind waves. Part 2. Dissipation function and evolution tests. Journal of Physical Oceanography, 40(4), 667-683
  • Tsagareli, K.N., A.V. Babanin, D.J. Walker, and I.R. Young, 2010: Numerical investigation of spectral evolution of wind waves. Part 1. Wind input source function. Journal of Physical Oceanography, 40(4), 656-666


  • Banner, M. L., and R. P. Morison, “Refined source terms in wind wave models with explicit wave breaking prediction. part I: Model frame-

work and validation against field data,” Ocean Modelling, vol. 33, pp. 177–189, 2010.

  • Young, I.R., and A.V. Babanin, 2006: Spectral distribution of energy dissipation of wind-generated waves due to dominant wave breaking. Journal of Physical Oceanography, 36(3), 376–394
  • Manasseh, R., A.V. Babanin, C. Forbes, K. Rickards, I. Bobevski, and A. Ooi, 2006: Passive acoustic determination of wave-breaking events and their severity across the spectrum. Journal of Atmospheric and Oceanic Technology, 23(4), 599–618

Wind Input

  • Donelan, M.A., A.V. Babanin, I.R. Young, and M.L. Banner, 2006: Wave follower measurements of the wind input spectral function. Part 2. Parameterization of the wind input. Journal of Physical Oceanography, 36(8), 1672-1688

Babanin, A.V., M.L. Banner, I.R. Young, and M.A. Donelan, 2007: Wave follower measurements of the wind input spectral function. Part 3. Parameterization of the wind input enhancement due to wave breaking. Journal of Physical Oceanography, 37(11), doi: 10.1175/JPO3147.1, 2764–2775

Spectrum tail

Forcing: winds, sea ice, icebergs, currents, water levels


  • H. L. Tolman, “Limiters in third-generation wind wave models,” Global Atmos. Ocean Syst., vol. 8, pp. 67–83, 2002.
  • A. J. van der Westhuysen, M. Zijlema, and J. A. Battjes, “Improvement of the numerics and deep-water physics in an academic version of SWAN,” in Proceedings of the 29th International Conference on Coastal Engineering, Lisbon, Portugal, ASCE, 2004.
  • A. Roland, Development of WWM II: Spectral wave modelling on unstructured meshes. PhD thesis, Technische Universität Darmstadt, Institute of Hydraulic and Water Resources Engineering, 2008.

Other stuff ...

Stereo-video data and wave statistics