skip to content
 

Dissipation of wind waves by pancake and frazil ice in the autumn Beaufort Sea

Presented by: 
Erick Rogers U.S. Naval Research Laboratory
Date: 
Wednesday 6th September 2017 - 15:00 to 16:30
Venue: 
INI Seminar Room 2
Abstract: 
I will be presenting the following paper:
W.E. Rogers, J. Thomson, H.H. Shen M.J. Doble, P. Wadhams and S. Cheng, 2016:
Dissipation of wind waves by pancake and frazil ice in the autumn Beaufort Sea
Journal of Geophysical Research: Oceans vol 121 7991-8007 doi:10.1002/2016JC012251
The full paper may be found at the link above.
The abstract follows:
A model for wind-generated surface gravity waves, WAVEWATCH III (R), is used to analyze and interpret buoy measurements of wave spectra. The model is applied to a hindcast of a wave event in sea ice in the western Arctic, 11–14 October 2015, for which extensive buoy and ship-borne measurements were made during a research cruise. The model, which uses a viscoelastic parameterization to represent the impact of sea ice on the waves, is found to have good skill—after calibration of the effective viscosity—for prediction of total energy, but over-predicts dissipation of high frequency energy by the sea ice. This shortcoming motivates detailed analysis of the apparent dissipation rate. A new inversion method is applied to yield, for each buoy spectrum, the inferred dissipation rate as a function of wave frequency. For 102 of the measured wave spectra, visual observations of the sea ice were available from buoy-mounted cameras,and ice categories (primarily for varying forms of pancake and frazil ice) are assigned to each based on the photographs. When comparing the inversion-derived dissipation profiles against the independently derived ice categories, there is remarkable correspondence, with clear sorting of dissipation profiles into groups of similar ice type. These profiles are largely monotonic: they do not exhibit the ‘‘roll-over’’ that has been found at high frequencies in some previous observational studies.

The introduction to the seminar will include a general overview of wave forecasting for the Arctic.
Public release statement: The published paper has been approved for public release. The introduction/overview slides are pulled from earlier presentations which were approved for public release.
The video for this talk should appear here if JavaScript is enabled.
If it doesn't, something may have gone wrong with our embedded player.
We'll get it fixed as soon as possible.
University of Cambridge Research Councils UK
    Clay Mathematics Institute London Mathematical Society NM Rothschild and Sons