The wind sea period identifies
the period (the time between waves) of the locally generated waves (in cases
with strong local winds). Note that the peak period field shows discontinuities.
These discontinuities can loosely be interpreted as swell fronts, although
in reality many swell systems overlap at most locations and times.
Note on the viewer:
versions 6-8. Alternative browsers in which the viewer does perform
correctly include Firefox, Opera, Safari, Chrome, Konqueror, Omniweb,
Seamonkey, Camino, others. If you encounter difficulties with the viewer in
Internet Explorer, we suggest trying one of the other browsers.