Accession Number:

ADP013583

Title:

Spirals on the Sea: A Manifestation of Upper-Ocean Stirring

Descriptive Note:

Conference paper

Corporate Author:

SCRIPPS INSTITUTION OF OCEANOGRAPHY LA JOLLA CA

Personal Author(s):

Report Date:

2001-01-19

Pagination or Media Count:

6.0

Abstract:

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 linear features into spirals. The hypothesis needs to be tested by prolonged measurements and surface truth. Spiral eddies are a manifestation of a submesoscale oceanography associated with upper ocean stirring dimensional considerations suggest a horizontal diffusivity of order 10exp 3 sq ms.

Subject Categories:

  • Physical and Dynamic Oceanography

Distribution Statement:

APPROVED FOR PUBLIC RELEASE