NASA's Tropical Rainfall Measuring Mission (TRMM), QuikSCAT, and Aqua satellites each look at different factors of tropical cyclones to help generate better forecasts. TRMM focuses on the intensity of tropical rainfall, which is indicative of whether a cyclone is weakening or strengthening. QuikSCAT collects wind data, and Aqua records ocean and air temperatures and humidity. These factors are primary in the strengthening of a hurricane, and NASA researchers, working with hurricane forecasters from the National Hurricane Center (NHC) hope that the data generated from these satellites will improve hurricane predictions. Hopefully, these efforts will help lessen damages when another hurricane like Andrew strikes our coasts.
"Andrew's wind data was recently re-analyzed and found to have reached maximum sustained wind speeds of 165 mph at landfall in South Florida, making the hurricane a Category 5 on the Saffir-Simpson Hurricane Scale," said Max Mayfield, Director of the National Hurricane Center. Category 5 storms have winds over 155 mph and storm surges generally over 18 feet above normal sea level. This makes Andrew one of only three Category 5 hurricanes known to have struck the U.S.
On August 24th Andrew cut its destructive swath through south Florida and entered the Gulf of Mexico. During the morning of the 26th, Andrew made landfall 100 miles southwest of New Orleans, Louisiana and was downgraded to a tropical depression the next day, northeast of Jackson, Mississippi.
South Florida was ruled a federal disaster area, as entire neighborhoods were destroyed. Andrew caused more than $25 billion in damages (1992 dollars). The enormity of the damage created a new awareness of hurricanes and further prompted scientists to gain a better understanding of these deadly storms in an effort to predict and mitigate future similar catastrophic events.
Towards this goal, the NHC, part of the National Oceanic and Atmospheric Administration (NOAA), NASA and other federal agencies work together to provide the public with the best information possible. The NHC uses several computer models to help forecast and track the intensity of tropical cyclones. Each computer model includes air temperature and pressure, sea surface temperature, wind speed and humidity as recorded from hurricane hunter aircraft that fly above tropical cyclones and drop sensors into them to get this data. The NHC also verifies storm locations with NOAA's Geostationary Operational Environmental Satellite (GOES).
NASA's contributions include 3 Earth-watching satellites. "NASA's TRMM satellite has been very valuable in determining hurricane or tropical cyclone intensity and in improving hurricane track forecasting through the use of rainfall data into hurricane forecast computer models," said Bob Adler, TRMM Project Scientist at NASA's Goddard Space Flight Center, Greenbelt, Md. TRMM data have been combined with data from other satellites to detect heavy rain events and the associated flood potential due to tropical cyclones in areas where there is limited ground based information.
The SeaWinds instrument on NASA's Quick Scatterometer spacecraft, also known as Quikscat, is a specialized microwave radar that measures both the speed and direction of winds near the ocean surface. It is being used by many marine weather prediction centers to improve monitoring and forecasting tropical cyclones. In January 2002, the United States and Europe incorporated wind speed and direction data from Quikscat into their operational global weather analysis and forecast systems. Significant improvement has been demonstrated. NASA's Jet Propulsion Laboratory (JPL), a division of the California Institute of Technology, Pasadena, Calif., manages the Quikscat satellite for NASA's Office of Earth Science, Washington.
Another NASA satellite that will prove helpful with hurricane forecasts is the Aqua satellite launched by NASA in May of this year. The AIRS (Atmospheric Infrared Sounder) instrument, developed by NASA's JPL is the central part of the AIRS/AMSU (Advanced Microwave Sounding Unit)/HSB (Humidity Sounder for Brazil) instrument group that will obtain global temperatures and humidity records throughout the atmosphere. NASA hopes these data will lead to improved weather forecasts and improved determination of cyclone intensity, location and tracks and the severe weather associated with storms. "The improved data from Aqua will not make weather forecasting perfect, but should make it better," said Claire Parkinson, Aqua Project Scientist at NASA Goddard.
"People should be watchful and remember that it only took one hurricane named Andrew during 1992 to change the lives of hundreds of thousands in south Florida," said Scott Curtis researcher at NASA Goddard and University of Maryland Baltimore County, Baltimore, Md.
For more information and images:
The National Hurricane Center web site: http://www.
For images and animations of Hurricane Andrew and it's track:
For animations on Hurricanes as Heat Engines:
For the Aqua homepage: http://aqua.
For the Quikscat homepage: http://winds.
For the TRMM homepage: http://trmm.