Source of microbaroms from tropical cyclone waves
Article first published online: 4 MAR 2011
Copyright 2011 by the American Geophysical Union.
Geophysical Research Letters
Volume 38, Issue 5, 16 March 2011
How to Cite
2011), Source of microbaroms from tropical cyclone waves, Geophys. Res. Lett., 38, L05602, doi:10.1029/2010GL046390., , , and (
- Issue published online: 4 MAR 2011
- Article first published online: 4 MAR 2011
- Manuscript Accepted: 18 JAN 2011
- Manuscript Revised: 11 JAN 2011
- Manuscript Received: 3 DEC 2010
- tropical cyclones;
- numerical wave modeling
 Microbaroms are continuous infrasonic signals with a dominant frequency around 0.2 Hz produced by ocean surface waves. Monitoring stations around the globe routinely detect strong microbaroms in the lee of tropical cyclones. We utilize a parametric wind model and a spectral wave model to construct the tropical cyclone wave field and a theoretical acoustic source model to describe the intensity, spatial distribution, and dynamics of microbarom sources. This approach excludes ambient wave conditions and facilitates a parametric analysis to elucidate the source mechanism within the storm. A stationary tropical cyclone produces the strongest microbarom signals at the center, where the waves generated by the cyclonic winds converge. As the tropical cyclone moves forward, the converging wave field becomes less coherent and lags and expands behind the storm center. The models predict a direct relation between the storm forward speed and the location of maximum microbarom source intensity consistent with the infrasonic observations from Hurricane Felicia 2009 in the North Central Pacific.