HR: 0800h
AN: A21E-0797    [Abstracts]
TI: Observation of Large Amplitude Inertial Gravity Waves and Their Link to the Upper Tropospheric Jet
AU: * Wang, L
EM: lwang@cora.nwra.com
AF: NorthWest Research Associates Inc., Colorado Research Associates Div., 3380 Mitchell Lane, Boulder, CO 80301, United States
AU: Fritts, D C
EM: dave@cora.nwra.com
AF: NorthWest Research Associates Inc., Colorado Research Associates Div., 3380 Mitchell Lane, Boulder, CO 80301, United States
AU: Schmidlin, F J
EM: Francis.J.Schmidlin@hasa.gov
AF: NASA/GSFC/Wallops Flight Facility, Code 972 NASA/GSFC/Wallops Flight Facility, Wallops Island, 23337, United States
AB: We examined large amplitude lower stratospheric gravity wave events from radiosonde measurements conducted over a US mid-latitude site in winter. Using the combined hodograph and wavelet analysis, we derived the complete set of wave parameters and found that the waves had intrinsic frequency of 1.3-1.5 f (where f is the Coriolis parameter), vertical wavelength of 2.1-2.7 km, horizontal wavelengths of 400-500 km, and total energy density of up to 50 J/kg. Also, the intrinsic propagation directions were estimated to be toward the Northwest. The derived wave parameters allow us to trace the possible sources of the events using the ray-tracing technique. We concluded that the waves were very likely originated from the upper tropospheric jet exit region via the spontaneous imbalance mechanism. We also compared various diagnostic tools to quantify unbalanced flow, and compared our observations with existing model studies on inertial gravity waves generated from jet streaks.
DE: 3280 Wavelet transform (3255, 4455)
DE: 3285 Wave propagation (0689, 2487, 4275, 4455, 6934)
DE: 3334 Middle atmosphere dynamics (0341, 0342)
DE: 3362 Stratosphere/troposphere interactions
SC: Atmospheric Sciences [A]
MN: 2007 Fall Meeting