Abstract
Whitecap coverage, which influences microwave and short wave radiation from the sea sur
face, is not only a non-linear function of the surface wind speed, but also is influenced by other
physical parameters. Dependence of whitecapping on the wind speed, sea surface temperature
(SST), surface air temperature (SAT), fetch and duration are discussed with data obtained by insitu
observation from a view point of atmospheric correction for ocean color sensors. The whitecap
coverage was estimated by photographs taken from high altitude platforms. Wind speed,
water and air temperature were measured synchronously with the photography, and their relation
ships with the coverage were analyzed, by principal component and multiple regression analyses.
The results show that the whitecap coverage depends on the wind speed as pointed out by previ
ous investigations but also varies with changes in SST, SAT, atmospheric stability and fetch. And
it is found that the factors of whitecapping can be expressed with following three components;
thermal stability of the sea surface, dynamic disturbance by the sea surface wind, development of
wind waves. Finally, an effective empirical model which can estimate whitecap coverage with
other ”surface parameters” , is proposed.
