Breakthrough in hurricane study

Researchers believe they have found a new way to monitor the intensity and location of hurricanes from hundreds of miles away by detecting atmospheric waves that radiate from a storm’s centre. Scientists from the University of Miami (UM) Rosenstiel School of Marine and Atmospheric Science in Florida, and the Hurricane Research Division of the National Oceanic and Atmospheric Administration (NOAA), presented direct observations of the waves, obtained by NOAA aircraft flying in hurricanes and by a research buoy located in the Pacific Ocean. The waves, known as atmospheric gravity waves, are produced by strong thunderstorms near the eye and radiate outwards in expanding spirals. “These very subtle waves can sometimes be seen in satellite images,” said David Nolan, professor in the Department of Atmospheric Sciences at the Rosenstiel School and lead author of the study. “We were able to measure them in aircraft data and surface instruments.” Nolan said that computer simulations performed at the UM Center for Computational Science can reproduce the waves, showing that the wave strengths can be related to the maximum wind speed in the core of the storm. These findings suggest that hurricanes, cyclones and typhoons could be monitored from hundreds of miles away with relatively inexpensive instruments, such as barometers and anemometers, much like earthquakes from around the world are monitored by seismometers. The researchers analysed data obtained from 25 different penetrations by NOAA P3 aircraft into five hurricanes in 2003 and 2004, as well as data from the Extreme Air-Sea Interaction (EASI) buoy deployed in the Pacific Ocean by UM Rosenstiel School scientists in 2010. The study, Spiral Gravity Waves Radiating from Tropical Cyclones, was published in the journal Geophysical Research Letters.