Digital Commons Network^™

Observational Investigations Of Gravity Wave Momentum Flux With Spectroscopic Imaging, J. Tang, G. R. Swenson, Alan Z. Liu, F. Kamalabadi

Alan Z Liu

We apply a newly developed gravity wave momentum flux estimation method to the mesospheric measurements obtained with colocated airglow imager and meteor radar at Maui, Hawaii (20.7ºN, 156.3ºW), during the Maui Mesosphere and Lower Thermosphere (Maui MALT) campaign. The method identifies individual quasi-monochromatic gravity waves with periods between 6 and ~40 min, estimates the intrinsic wave parameters, and calculates the momentum fluxes carried by vertically propagating waves. Data taken on 28 October 2003 are analyzed in detail to reveal the relationship between momentum flux and wave parameters. The January, April, July, and October 2003 data are divided into summer and …

Seasonal Variations Of The Vertical Fluxes Of Heat And Horizontal Momentum In The Mesopause Region At Starfire Optical Range, New Mexico, Chester S. Gardner, Alan Z. Liu

Alan Z Liu

Lidar observations of wind and temperature profiles between 85 and 100 km, conducted at the Starfire Optical Range (SOR), New Mexico, are used to characterize the seasonal variations of the vertical fluxes of heat and horizontal momentum and their relationships to gravity wave activity in this region. The wind and temperature variances exhibit strong 6-month oscillations with maxima during the summer and winter that are about 3 times larger than the spring and fall minima. The vertical heat flux also exhibits strong 6-month oscillations with maximum downward flux during winter and summer. The downward heat flux peaks near 88 km …

High Frequency Gravity Waves Observed In Oh Airglow At Starfire Optical Range, Nm: Seasonal Variations In Momentum Flux, Jing Tang, Alan Z. Liu, Gary R. Swenson

Alan Z Liu

Airglow imager and Na wind/temperature lidar measurements at Starfire Optical Range, New Mexico (35ºN, 107ºW) are used to estimate the seasonal variation of the vertical fluxes of horizontal momentum carried by high frequency Atmospheric Gravity Waves (AGWs). The cross-correlation coefficients between the vertical and horizontal wind perturbations were calculated from the OH airglow imager data collected during 32 nights in 1998, 1999 and 2000. The RMS wind velocities were deduced from the lidar measurements. The combined information was used to estimate the upper limit of the momentum flux. The meridional component of the vertical flux of horizontal momentum was observed …

Diurnal Variation Of Gravity Wave Momentum Flux And Its Forcing On The Diurnal Tide, Alan Z. Liu, Xian Lu, Steven Franke

Alan Z Liu