Concluding Analysis of IR Measurements of Microbreaking and Whitecaps
Abstract
Analysis of existing field and laboratory measurements using infrared techniques to study wave breaking was concluded by accomplishing two tasks. The field data were from the Fluxes, Air-sea Interaction, and Remote Sensing (FAIRS) experiment that took place off Monterey, California, in the fall of 2000. The laboratory data were obtained at the NASA Goddard Wallops Flight Facility in 1998 and 2004. The first task was the use of infrared (IR) imagery to determine the extent to which microbreaking waves are modulated by swell waves. In 1998 and 2004, The authors conducted laboratory measurements using an IR imager of wind-generated waves superimposed on paddle-generated waves. The laboratory results suggested that modulation of the skin temperature observed in the field was due to modulation of microbreaking by swell waves. The second task involved the correlation of microbreaking with radar backscatter. Gravity-capillary waves bound to the forward face of swell waves have been postulated to be the cause of large Doppler shifts in radar backscatter at high incidence angles. To investigate the relationship between these bound scatterers and microbreakers, the authors made simultaneous, collocated IR, video, and radar measurements during FAIRS. Microbreakers were identified as waves that produced a warm wake in the IR imagery, but no visible signature in the video. The large Doppler shift in the radar data associated with these waves supports the idea that microbreaking waves are a source of bound scatterers in radar return from the ocean.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 30, 2004
- Accession Number
- ADA457990
Entities
People
- Andrew T. Jessup
- Ruth Branch
Organizations
- University of Washington