Dissipation of wind waves by pancake and frazil ice in the autumn Beaufort Sea
Duration: 1 hour 25 mins
Share this media item:
Embed this media item:
Embed this media item:
About this item
Description: |
Rogers, E
Wednesday 6th September 2017 - 15:00 to 16:30 |
---|
Created: | 2017-09-08 13:22 |
---|---|
Collection: | Mathematics of sea ice phenomena |
Publisher: | Isaac Newton Institute |
Copyright: | Rogers, E |
Language: | eng (English) |
Distribution: | World (downloadable) |
Explicit content: | No |
Aspect Ratio: | 16:9 |
Screencast: | No |
Bumper: | UCS Default |
Trailer: | UCS Default |
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. |
---|
Available Formats
Format | Quality | Bitrate | Size | |||
---|---|---|---|---|---|---|
MPEG-4 Video | 640x360 | 1.9 Mbits/sec | 1.19 GB | View | Download | |
WebM | 640x360 | 1.08 Mbits/sec | 689.06 MB | View | Download | |
iPod Video | 480x270 | 490.45 kbits/sec | 305.34 MB | View | Download | |
MP3 | 44100 Hz | 250.35 kbits/sec | 155.86 MB | Listen | Download | |
Auto * | (Allows browser to choose a format it supports) |