Hurricane Elena
August 28-September 4, 1985
Hurricane Elena's erratic path over the Gulf of Mexico forced
the evacuation of nearly one million people from low-lying coastal
areas from Tampa, Florida to New Orleans, Louisiana. At the time, it was the largest
peacetime evacuation in U.S. history. After hovering off the West
Florida coast for six days, Elena finally made landfall near Biloxi,
Mississippi on September 2 as a category 3 hurricane. Estimates of the
total economic loss from Elena were near $1.3 billion.
Ocean Turbidity
Three days after Elena made landfall a higher turbidity signal
can be seen in the area off Cape St. George, Florida (partially obscured
by clouds) as well as in a band of turbid water in Waccasassa
Bay, Florida. The turbidity in the vicinity of the Mississippi Delta is
not especially high after Elena but no comparison is possible
due to clouds in the before image. Sunglint is apparent
in the left of the after image.
| Before | After | Difference (after minus before) |
Sea Surface Temperature
The after image depicts a dramatic cool "filament"
just off the coast in the center of the image. With its "hammerhead"
or "mushroom" feature it is not unlike the cool filaments
and jets that are commonly observed in coastal upwelling areas
such as off the west coast of North America in the spring and
summer. The implied counter-clockwise circulation is opposite
to the normal clockwise circulation of the Loop Current suggesting
a region of high surface shear. It is an unusual feature to find
in the Gulf of Mexico and was most likely caused by an intense
hurricane wind generated sea surface divergence (i.e., upwelling).
This image is in contrast to other hurricane SST images that depict
regional areas of cooling that are more likely due to upper ocean
heat loss rather than upwelling.
| Before | After | Difference (after minus before) |
For scientists more time series Satellite Images in GEOTIFF Format
are available
