Hurricane Isabel blasted through the Caribbean and southeastern United States, leaving behind a trail of destruction, but also a trail of information. More than 20 buoys deployed in the Caribbean by an Office of Naval Research project were left drifting in the storm's wake, awaiting retrieval and the chance to reveal Isabel's deepest secrets. How much rain did she drop? How did the water temperature vary? How quickly did the water move, how fiercely did the wind blow?
Acoustic sensors, vertical profilers, and drifting buoys were dropped into the path of Isabel (and her recent predecessor, Fabian) to find answers to these questions as part of an ONR-funded project called CBLAST, for Coupled Boundary Layers/Air-Sea Transfer.
Under this project, researchers from several universities and government research agencies develop new data-collection instruments and computer models to understand and predict the energy transfer between the atmosphere and sea. They flew several of their new instruments into the storms to measure the characteristics of waves, spray, rain, and wind in Category 3 to 5 hurricanes.
"We have a good hurricane track warning system, but we want certainty on intensity: how much rainfall, how big a storm surge, and how strong a wind it will bring," explains Carl Friehe, marine meteorologist and CBLAST program manager at the Office of Naval Research.
"Knowing these particulars could save many lives and a great deal of money for citizens and the Navy alike," according to Theresa Paluszkiewicz, ONR program manager for ocean modeling and prediction. For Navy ships in port, for example, a hurricane's storm surge is its greatest threat. But sending the fleet to sea is an expensive undertaking and the Navy would benefit from greater accuracy in predicting a storm's landfall and surge.
The data collected during Hurricanes Isabel and Fabian will provide the necessary physics to build better predictive models, and also test our interpretation of data from other sources, including satellites. The buoy drops and airplane flights were carried out for ONR by the 53rd Weather Reconnaissance Squadron of the Air Force Reserves, who made sure the buoys were dropped at the right time and place, and that the flights were safe and successful. The research is being overseen by the Hurricane Research Division at the National Oceanographic and Atmospheric Administration's Atlantic Oceanographic and Meteorological Laboratory, led by NOAA scientist Peter Black.