This sea surface height map of the Gulf of Mexico and the northwestern
Caribbean Sea, with the Florida peninsula on the upper right, is based on
altimeter data from three satellites including NASA's Jason-1. Red
indicates a strong circulation of much warmer waters, which can feed
energy to a hurricane. This area stands 35 to 45 centimeters (about 13 to
17 inches) higher than the surrounding waters of the Gulf. The actual
track of a hurricane is primarily dependent upon steering winds, which
are forecasted through the use of atmospheric models. However, the
interaction of the hurricane with the upper ocean is the primary source
of energy for the storm. Hurricane intensity is therefore greatly affected
by the upper ocean temperature structure and can exhibit explosive growth
over warm ocean currents and eddies. According to the forecasted track
through the Yucatan Channel, Hurricane Wilma will cross the Yucatan
Peninsula and then turn sharply to the northeast, passing over the warm
waters of the Gulf of Mexico circulation feature called the Loop Current
on its way towards southeast Florida. The storm may intensify as it passes
over the warm water of the Loop Current.
The Jason-1 satellite carries a dual-frequency radar altimeter. This
instrument beams microwave pulses-at 13.6 and 5.3 Gigahertz,
respectively-downward toward the Earth. To determine the ocean's height,
the instrument precisely measures the time it takes for the microwave
pulses to bounce off the surface and return to the spacecraft. This
measure, multiplied by the speed of light, gives the range from the
satellite to the ocean surface.
The joint U.S.-French Jason-1 mission is managed by the JPL for NASA's
Earth Science Enterprise, NASA Headquarters, Washington, D.C. JPL is a
division of the California Institute of Technology in Pasadena. Research
on Earth's oceans using Jason-1 and other space-based capabilities is
conducted by NASA's Earth Science Enterprise to better understand and
protect our home planet. For more information on Jason-1, see
http://sealevel.jpl.nasa.gov.)