Difference between revisions of "Radiation stress"

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Definition|title=Radiation stress
 
Definition|title=Radiation stress
|definition= Radiation stress is the flux of momentum, which is carried by the ocean waves. When these waves break, that momentum is transferred to the water column, forcing nearshore currents. Forcing due to these radiation stress gradients is commonly several orders of magnitude greater than forcing due to wind of other wave nonlinearities.<ref>CoPraNet glossary [http://www.coastalpractice.net/glossary/index.htm]</ref> <ref>wikipedia [http://en.wikipedia.org/wiki/Radiation_stress_tensor]</ref>.  
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|definition= Radiation stress is the flux of momentum carried by ocean waves.  
 
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==Notes==
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The fact that waves can exert a net force on the water body directed along the wave propagation direction was first recognised by Longuet-Higgins and Stewart (1962<ref>Longuet-Higgins, M.S. and Stewart, R.W. 1962. Radiation stress and mass transport in gravity waves, with application to 'surf beats'. Journal of Fluid Mechanics 13: 481–504</ref>, 1964<ref>Longuet-Higgins, M.S. and Stewart, R.W. 1964. Radiation stresses in water waves; a physical discussion, with applications. Deep Sea Research 11: 529–562</ref>). The radiation stress is the momentum transferred through the water body per unit time (the flux of momentum) by wave orbital motion. It is called a stress because for obliquely incident waves, cross-shore momentum can be transferred by both cross-shore wave orbital motion and longshore wave orbital motion and longshore momentum can be transferred by both longshore wave orbital motion and cross-shore wave orbital motion. For obliquely incident waves, a cross-shore gradient in the wave orbital motion, for example due to wave breaking, will exert a stress on the water mass in cross-shore direction as well as in longshore direction. The stress in longshore direction generates a [[longshore current]]. The stress in cross-shore direction generates a [[Wave set-up|water level set-up]] at the coast.
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Forcing by radiation stress gradients related to wave breaking is commonly an order of magnitude greater than forcing due to wind stress or other wave nonlinearities.
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For a more detailed explanation, see [[Shallow-water wave theory#Radiation Stress (Momentum Flux)]] and [[Shallow-water wave theory#Radiation Stress Components for Oblique Waves]].
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==References==
 
==References==
 
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Revision as of 09:55, 3 July 2022

Definition of Radiation stress:
Radiation stress is the flux of momentum carried by ocean waves.
This is the common definition for Radiation stress, other definitions can be discussed in the article


Notes

The fact that waves can exert a net force on the water body directed along the wave propagation direction was first recognised by Longuet-Higgins and Stewart (1962[1], 1964[2]). The radiation stress is the momentum transferred through the water body per unit time (the flux of momentum) by wave orbital motion. It is called a stress because for obliquely incident waves, cross-shore momentum can be transferred by both cross-shore wave orbital motion and longshore wave orbital motion and longshore momentum can be transferred by both longshore wave orbital motion and cross-shore wave orbital motion. For obliquely incident waves, a cross-shore gradient in the wave orbital motion, for example due to wave breaking, will exert a stress on the water mass in cross-shore direction as well as in longshore direction. The stress in longshore direction generates a longshore current. The stress in cross-shore direction generates a water level set-up at the coast. Forcing by radiation stress gradients related to wave breaking is commonly an order of magnitude greater than forcing due to wind stress or other wave nonlinearities.

For a more detailed explanation, see Shallow-water wave theory#Radiation Stress (Momentum Flux) and Shallow-water wave theory#Radiation Stress Components for Oblique Waves.


References

  1. Longuet-Higgins, M.S. and Stewart, R.W. 1962. Radiation stress and mass transport in gravity waves, with application to 'surf beats'. Journal of Fluid Mechanics 13: 481–504
  2. Longuet-Higgins, M.S. and Stewart, R.W. 1964. Radiation stresses in water waves; a physical discussion, with applications. Deep Sea Research 11: 529–562