Probability Distribution of Surface Wave Slope Derived Using Sun Glitter Images from Geostationary Meteorological Satellite and Surface Vector Winds from Scatterometers |
| |
| Authors: | Naoto Ebuchi Shoichi Kizu |
| |
| Institution: | (1) Center for Atmospheric and Oceanic Studies, Graduate School of Science, Tohoku University, Aoba, Sendai 980-8578, Japan;(2) Department of Geophysics, Graduate School of Science, Tohoku University, Aoba, Sendai 980-8578, Japan |
| |
| Abstract: | The probability distribution of the sea surface slope has been estimated using sun glitter images derived from the visible
wavelength radiometer on the Geostationary Meteorological Satellite (GMS) and surface vector winds observed by spaceborne
scatterometers. The brightness of the visible images is converted to the probability of wave surfaces which reflect the sunlight
toward GMS in grids of 0.25° × 0.25° (latitude × longitude). The slope and azimuth angle required for the reflection of the
sun's rays toward GMS are calculated for each grid from the geometry of GMS observation and location of the sun. The GMS images
are then collocated with surface wind data observed by three scatterometers. Using the collocated data set of about 30 million
points obtained in a period of 4 years from 1995 to 1999, the probability distribution function of the surface slope is estimated
as a function of wind speed and azimuth angle relative to the wind direction. The results are compared with those of Cox and
Munk (1954a). The surface slope estimated by the present method shows a narrower distribution and much less directivity relative
to the wind direction than that reported by Cox and Munk. It is expected that their data were obtained under conditions of
growing wind waves. In general, wind waves are not always developing, and the slope distribution might differ from the results
of Cox and Munk. Most of our data are obtained in the subtropical seas under clear-sky conditions. This difference in the
conditions may be the reason for the difference of slope distribution.
This revised version was published online in July 2006 with corrections to the Cover Date. |
| |
| Keywords: | Wind waves surface slope sun glitter scatterometer Geostationary Meteorological Satellite visible radiometer |
| 本文献已被 SpringerLink 等数据库收录！ |
|
