|Spirals on the sea|
Munk, W. (2001). Spirals on the sea, in: Gili, J.-M. et al. (Ed.) A Marine Science Odyssey into the 21st Century. Scientia Marina (Barcelona), 65(Suppl. 2): pp. 193-198
In: Gili, J.-M.; Pretus, J.L.; Packard, T.T. (Ed.) (2001). A Marine Science Odyssey into the 21st Century. Scientia Marina (Barcelona), 65(Suppl. 2). Institut de Ciències del Mar: Barcelona. 326 pp., more
In: Scientia Marina (Barcelona). Consejo Superior de Investigaciones Científicas. Institut de Ciènces del Mar: Barcelona. ISSN 0214-8358, more
|Also published as |
- Munk, W. (2001). Spirals on the sea. Sci. Mar. (Barc.) 65(Suppl. 2): 193-198, more
Spiral eddies were first seen in the sun glitter on the Apollo Mission 30 years ago; they have since been recorded on SAR missions and in the infrared. The spirals are globally distributed, 10-25 km in size and overwhelmingly cyclonic. They have not been explained. Under light winds favorable to visualization, linear surface features with high surfactant density and low surface roughness are of common occurrence. We have proposed that frontal formations concentrate the ambient shear and prevailing surfactants. Horizontal shear instabilities ensue when the shear becomes comparable to the coriolis frequency. The resulting vortices wind the liner features into spirals. The hypothesis needs to be tested by prolonged measurements and surface truth. Spiral eddies are a manifestation of a sub-mesoscale oceanography associated with upper ocean stirring; dimensional considerations suggest a horizontal diffusivity of order 103 m2 s-1.