Observation of Gravity Waves during the Genesis of Atlantic Lows Experiment.
Abstract
The principle objective of GALE (Genesis of Atlantic Lows Experiment) was to study various mesoscale processes and their role in cyclogenesis along the East Coast of the United States. A supporting objective was to study the role of gravity waves in the organization of precipitation bands. Several mesoscale disturbances resembling gravity waves passed through the data network during the three day test period. A high-pass spectral filter was applied to the pressure, temperature, and wind fields to isolate the higher frequencies with periods of 8 hours or less. The filtered data were plotted using an objective analysis scheme which interpolated the data to an evenly spaced grid. A spatial filter was also applied to remove wavelengths less than twice the original station spacing. The horizontal divergence was calculated using the filtered wind field. Four gravity wave cases were identified from the surface pressure and divergence fields. Phase speeds ranged from 20-40 m/s with wavelengths from 200-400 km, and amplitudes of 0.25-2.0 mb. Further analysis was performed on case using sounding data. A comparison with linear gravity wave theory suggests that the gravity waves were freely propagating rather than a surface response to upper level forcing. While the waves were not directly associated with a frontal system, the Appalachian Mountains may have played a role in their information.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 04, 1987
- Accession Number
- ADA186819
Entities
People
- Donna M. Wojtak
Organizations
- Air Force Institute of Technology