NR 150 1st Edition Lecture 10 Outline of Last Lecture I Mass flow of ocean water is driven by wind and gravity II Surface currents flow around the periphery of ocean basins III Seawater flows in six great surface circuits IV Gyres with and without the Coriolis effect V Westward intensification VI The center of the gyres Outline of Current Lecture VII Circulation vs Waves VIII Waves Concept Current Lecture I Circulation vs Waves a Circulation i Transport mass 1 Ekman transport 2 Geostrophic flow ii Affected by Coriolis iii Examples gyres b Waves i Transfer energy ii Not affected by Coriolis iii Example stadium waves II Waves Concept These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute a Waves transmit energy not water mass across the ocean s surface b Because waves have no mass they aren t affected by the Coriolis force c Ocean waves are orbital waves in which water molecules move in closed circles orbits as the wave passes d Anatomy of a Progressive Wave i Frequency number of wave crests highest point of a wave passing point A or Point B each second ii Period time required for a wave crest at Point A to reach Point B iii Trough lowest point of a wave e The behavior of waves is influenced by the depth of the water through which they are moving i Deep water waves depth greater than half of the wavelength L 2 ii Shallow water waves depth is less than L 20 f Wind blowing over the ocean generates waves g Capillary waves ripples i Wind acts as a disturbing force ii Surface tension acts as the restoring force h Combers or whitecaps form i If the wave s steepness 1 7 ratio of height length or 120 degree angle ii Wind energy is dissipated as heat i Wind waves travel in groups called wave trains i Wind waves store more energy than any other wave type j Many factors influence wind wave development i Swell the smooth undulation of ocean water caused by wave dispersion ii Wind strength wind must be moving faster than the wave crest for energy transfer to continue iii Wind duration winds that blow for a short time will not generate large waves iv Fetch uninterrupted distance over which the wind blows without significant change in direction v Fully developed sea the maximum wave size possible for a wind of specific strength duration and fetch k Wave heights are the highest where there is no interference of continents Antarctic l Interference produces irregular wave motions i Waves meeting interfere with one another ii Destructive interference two waves can cancel each other out iii Constructive interference additive interference that results in waves larger than the original waves iv Rogue wave interference results in a wave crest higher than the theoretical maximum m Other waves i Shallow water waves 1 Deep water waves change to shallow water waves as they approach the shore ii Internal waves 1 Can form between layers of differing densities iii Standing waves 1 Seiche rocking back and forth at a specific resonant frequency in a confined area iv Storm surges 1 An abrupt bulge of water driven on shore by a tropical cyclone hurricane or a frontal storm 2 Created by low atmospheric pressure underneath the storm 3 Short lived but can be up to 7 5 meters high 4 Consists of only a crest v Tidal waves 1 Rogue waves are not tidal waves 2 Large sets of windwaves are not tidal waves 3 Tsunamis are not tidal waves 4 Storm surges are not tidal waves n Waves refract when they approach a shore at an angle