High-Resolution Image
HurricanesÕ eyes are often round, but they occasionally have polygonal shapes--from triangles to hexagons. These polygonal shapes are often incomplete, but segments of the shapes are distinct. This picture shows hurricane Ivan as it was approaching Florida on September 14, 2004. IvanÕs eye had a square shape and one corner of it was not well-formed. Research (e.g. Schubert, et al.,
J. Atmos. Sci., 1999, 1197-1223) has shown that polygonal eye-walls are a result of instability of the wind structure near the radius of maximum winds. HurricanesÕ eyes do not always have clear sky and calm winds. On occasions they can have small vortices associated with tall clouds and high winds (Kossin and Schubert,
Bull. Am. Meteor. Soc., 2004, 151-153.
Also see:
http://earthobservatory.nasa.gov/Newsroom/NewImages/images.php3?img_id=698
http://earthobservatory.nasa.gov/Newsroom/NewImages/images.php3?img_id=10309
http://earthobservatory.nasa.gov/Newsroom/NewImages/images.php3?img_id=16659, and
http://earthobservatory.nasa.gov/Newsroom/NewImages/images.php3?img_id=4494
(Contributed by Winston Chao)