Available online
Description
This programme deals with the question of storm wave attenuation and where it occurs in the ocean. Dr. Walter Munk describes with the aid of film an experiment that he and several colleagues carrie...d out in 1963 to track wave energy around the Pacific Ocean. By way of an introduction to Dr. Munk, John Wright reviews some basic concepts of wave motion. These include a description of basic parameters such as wave height and period, orbital motion, relationship between wave height and energy, speed and frequency, dispersion, and group and phase velocities. John Wright returns to clarify the experimental techniques of the experiment and to present some of its results using two models of energy density/frequency/time to do this. Dr. Munk interprets the results showing that most of the attenuation occurs in the vicinity of the storm itself and very little away from it.
This programme deals with the question of storm wave attenuation and where it occurs in the ocean. Dr. Walter Munk describes with the aid of film an experiment that he and several colleagues carrie...d out in 1963 to track wave energy around the Pacific Ocean. By way of an introduction to Dr. Munk, John Wright reviews some basic concepts of wave motion. These include a description of basic parameters such as wave height and period, orbital motion, relationship between wave height and energy, speed and frequency, dispersion, and group and phase velocities. John Wright returns to clarify the experimental techniques of the experiment and to present some of its results using two models of energy density/frequency/time to do this. Dr. Munk interprets the results showing that most of the attenuation occurs in the vicinity of the storm itself and very little away from it.
| Module code and title: | S334, Oceanography |
|---|---|
| Item code: | S334; 05 |
| First transmission date: | 20-04-1978 |
| Published: | 1978 |
| Rights Statement: | |
| Restrictions on use: | |
| Duration: | 00:24:00 |
| + Show more... | |
| Producer: | Jean Nunn |
| Contributors: | Walter Munk; John Wright |
| Publisher: | BBC Open University |
| Keyword(s): | Attenuation; Dispersion; Energy density; FLIP; Group velocity; Interaction; Orbital motion; Spectrum |
| Footage description: | Film of waves breaking on rocks. John Wright (voice over) introduces the programme. Wright goes on to review some basic characteristics of waves. Shots of waves in a wave tank with animations superimposed. Wright goes on to explain how wave groups are formed in water and the relationship between wave speed and group speed. Shots of a ripple tank, animated wave forms and diagrams help to illustrate his points. Walter Munk, Scripps Institution of Oceanography, begins a discussion of an experiment conducted by him and his colleagues to discover where and how storm generated waves become attenuated. The experiment involved using the entire Pacific Ocean as a wave tank. Munk points out the data collecting stations on a map. Over film shots of Flip, a specialised research, vessel, animated diagrams and film of the various recording stations, Munk explains how the recording stations were set up and the method by which they collected their data. Over film of an Antarctic storm, film of the various recording stations and their equipment and film of the research vessel Flip going on stations, Munk looks at some of the data that was collected. Using a 3-D model of the energy/density spectrum obtained from the Honolulu recording station, John Wright interprets the findings of the above experiment. He adds traces from the other stations to the model and builds up a more complete picture of wave dispersion. Walter Munk, with the aid of a graph, sums up the experiment's results. He points out, particularly, where and when most of the attenuation took place. John Wright sums up the programme. |
| Master spool number: | 6HT/72669 |
| Production number: | FOU1590H |
| Videofinder number: | 876 |
| Available to public: | no |
