Quantifying hurricane wind speed with undersea sound
Wilson, Joshua David
MetadataShow full item record
Hurricanes, powerful storms with wind speeds that can exceed 80 m/s, are one of the most destructive natural disasters known to man. While current satellite technology has made it possible to effectively detect and track hurricanes, expensive 'hurricanehunting' aircraft are required to accurately classify their destructive power. Here we show that passive undersea acoustic techniques may provide a promising tool for accurately quantifying the destructive power of a hurricane and so may provide a safe and inexpensive alternative to aircraft-based techniques. It is well known that the crashing of wind-driven waves generates underwater noise in the 10 Hz to 10 kHz range. Theoretical and empirical evidence are combined to show that underwater acoustic sensing techniques may be valuable for measuring the wind speed and determining the destructive power of a hurricane. This is done by first developing a model for the acoustic intensity and mutual intensity in an ocean waveguide due to a hurricane and then determining the relationship between local wind speed and underwater acoustic intensity. Acoustic measurements of the underwater noise generated by hurricane Gert are correlated with meteorological data from reconnaissance aircraft and satellites to show that underwater noise intensity between 10 and 50 Hz is approximately proportional to the cube of the local wind speed. From this it is shown that it should be feasible to accurately measure the local wind speed and quantify the destructive power of a hurricane if its eye wall passes directly over a single underwater acoustic sensor. The potential advantages and disadvantages of the proposed acoustic method are weighed against those of currently employed techniques. It has also long been known that hurricanes generate microseisms in the 0.1 to 0.6 Hz frequency range through the non-linear interaction of ocean surface waves. Here we model microseisms generated by the spatially inhomogeneous waves of a hurricane with the non-linear wave equation where a second-order acoustic field is created by first-order ocean surface wave motion. We account for the propagation of microseismic noise through range-dependent waveguide environments from the deep ocean to a receiver on land. We compare estimates based on the ocean surface wave field measured in hurricane Bonnie with seismic measurements from Florida.
Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution June 2006
Showing items related by title, author, creator and subject.
Bowers, Colleen Marie (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2006-09)Recent studies have shown that the presence of sand ripples on the seabed improves sonar detection of buried mines at sub-critical angles. Sidescan sonar data of ripples on the west Florida shelf were collected as part ...
Lane, D. Philip (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2011-09)Hurricane activity in the Northeastern Gulf of Mexico and its relationship to regional and large-scale climate variability during the Late Holocene is explored. A 4500-year record of hurricane-induced storm surges is ...
Hurricane impacts on the Caribbean coastal/marine environment : using scientific assessment to plan for the future Aubrey, David G.; Giese, Graham S.; Burdick, D. M.; Agardy, M. T.; Haney, J. Christopher; Gable, F. J. (Woods Hole Oceanographic Institution, 1991-09)The passage of Hurricane Hugo through the eastern Caribbean provided a unique opportunity for multidisciplinary study of (1) the effects of severe storms on tropical coastal and marine ecosystems, and (2) the physical and ...