Accession Number:

ADA114429

Title:

Measurements of Whitecap Coverage and Surface Winds Over the Gulf of Mexico Loop Current,

Descriptive Note:

Corporate Author:

NAVAL OCEAN RESEARCH AND DEVELOPMENT ACTIVITY NSTL STATION MS

Personal Author(s):

• Smith,Peter M.

Report Date:

1981-10-01

Pagination or Media Count:

28.0

Abstract:

The fraction of the ocean surface covered by whitecaps has long been thought to be some monotonically increasing function of the prevailing wind velocity at least for large fetches. In order to determine the extent to which other factors such as air column stability or water mass type can influence the areal coverage of whitecaps, photographic data was collected over the Loop Current from a NAVOCEANO P-3 aircraft. The variation of whitecap coverage along a line of closely spaced 25 km stations was determined and compared with other aircraft and data buoy information. The data indicates that, on the day of the flight, white-capping within the boundaries of the Loop Current depended little on the local wind, but demonstrated a noticeable dependence on air column stability. The strength and nature of this dependence varied over mesoscale distances. These results indicate that microwave radiometric measurements can be sensitive to variables other than surface wind since microwave brightness is quite sensitive to sea foam. The value of areal whitecap coverage as a measurable geophysical variable is also examined.

Descriptors:

• *Ocean waves
• Mexico Gulf
• Ocean currents
• Loops
• Aerial reconnaissance
• Infrared photography
• Wind
• Stresses
• Sea states

Subject Categories:

• Meteorology
• Physical and Dynamic Oceanography
• Photography

Distribution Statement:

APPROVED FOR PUBLIC RELEASE