Repository logo

Effects of air-sea interaction parameters on ocean surface microwave emission at 10 and 37 GHz

dc.contributor.authorHorgan, Kevin A., author
dc.contributor.authorGaiser, Peter W., author
dc.contributor.authorRose, Louis Allen, 1938-, author
dc.contributor.authorAhser, William E., author
dc.contributor.authorReising, Steven C., author
dc.contributor.authorAziz, Mohammed A., author
dc.contributor.authorIEEE, publisher
dc.description.abstractWindSat, the first polarimetric radiometer on orbit, launched in January 2003, provides the promise of passive ocean wind vector retrievals on a continuous basis, simultaneous with the retrieval of many other geophysical variables such as sea surface temperature, atmospheric water vapor, cloud liquid water, and sea ice extent and concentration. WindSat also serves as risk reduction for the upcoming National Polar-orbiting Operational environmental Satellite System (NPOESS) Conical Scanning Microwave Imager/Sounder (CMIS). Since the dependence of microwave brightness temperatures on wind direction is small relative to that of other parameters such as wind speed, wind direction retrieval relies on increasingly accurate knowledge of the ocean surface microwave emission, which depends upon surface properties such as roughness and foam due to wave breaking. Coordinated near-surface measurements of ocean surface microwave emission and air-sea interaction parameters are needed to quantify the effects of the processes mentioned above in surface emission models to improve the accuracy of wind vector retrievals. Such coordinated observations were performed during the Fluxes, Air-Sea Interaction, and Remote Sensing (FAIRS) experiment conducted on the R/P Floating Instrument Platform (FLIP) in the northeastern Pacific Ocean during the Fall of 2000. X- and Ka-band partially polarimetric radiometers were mounted at the end of the port boom of R/P FLIP to measure ocean surface emission at incidence angles of 45°, 53°, and 65°. A bore-sighted video camera recorded the fractional area of foam in the field of view of the radiometers. Air-sea interaction parameters that were measured concurrently include wind speed, friction velocity, heat fluxes, and significant wave height. The measured dependence of ocean surface emissivity on wind speed and friction velocity is in good agreement with, and extends, earlier observations and empirical models based on satellite data. Concurrent radiometric measurements and fractional area foam coverage data strengthen the possibility of retrieval of sea surface foam coverage using airborne or spaceborne radiometry. The dependence of emissivity on atmospheric stability is shown to be much smaller than the dependence of emissivity on wind speed. Analysis of emissivity dependence on atmospheric stability alone was inconclusive, due to the variation in atmospheric stability with wind speed. The effect of long-wave incidence angle modulation on sea surface emissivity for near-surface measurements was found to be negligible when emissivity measurements were averaged over tens to hundreds of long waves.
dc.description.sponsorshipThis was supported in part by the Department of the Navy, Office of Naval Research under Awards N0014-00-1-0280 and N00014-03-1-0044 to the University of Massachusetts, Award N0014-00-1-0152 to the University of Washington, and Award N0014-00-WX2-1032 to the Naval Research Laboratory, and in part by the National Polar-orbiting Operational environmental Satellite System (NPOESS) Integrated Program Office under Award NA02AANEG0338 to the Naval Research Laboratory. The FAIRS Experiment was sponsored by the Office of Naval Research through the Space and Remote Sensing, Marine Meteorology and Physical Oceanography Programs.
dc.format.mediumborn digital
dc.identifier.bibliographicCitationAziz, Mohammed A., et al., Effects of Air-Sea Interaction Parameters on Ocean Surface Microwave Emission at 10 and 37 GHz, IEEE Transactions on Geoscience and Remote Sensing 43, no. 8 (August 2005): 1763-1774.
dc.publisherColorado State University. Libraries
dc.relation.ispartofFaculty Publications
dc.rights©2005 IEEE.
dc.rightsCopyright and other restrictions may apply. User is responsible for compliance with all applicable laws. For information about copyright law, please see
dc.subjectair-sea interactions
dc.subjectfractional area foam coverage
dc.subjectfriction velocity
dc.subjectheat flux
dc.subjectmicrowave emissivity
dc.subjectmicrowave radiometry
dc.subjectmomentum flux
dc.subjectocean surface
dc.subjectocean surface emissivity
dc.subjectsignificant wave height
dc.subjectwind speed
dc.titleEffects of air-sea interaction parameters on ocean surface microwave emission at 10 and 37 GHz


Original bundle
Now showing 1 - 1 of 1
Thumbnail Image
817.83 KB
Adobe Portable Document Format