An Investigation of Intrinsic Gravity Wave Signatures Using Coordinated Lidar and Nightglow Image Measurements

Simultaneous observations of gravity waves using an Na wind/temperature lidar and a multi-wavelength all-sky nightglow imager were obtained, for the first time, during the ALOHA-93 campaign. A novel investigation of intrinsic wave parameters has been made by combining measurements of the horizontal wave components imaged in four nightglow emissions (height range ~80-100 kin) with Na lidar soundings of the horizontal wind field and temperature profiles over the same height interval. On October 19 both instruments registered marked monochromatic wave motions. The intrinsic periods of several of these waves have been determined and were found to vary considerably with altitude, often resulting in a significant increase over their observed wave periods. It is shown that these two instrumental techniques generally sampled different regions of the gravity wave spectrum: the lidar exhibiting most sensitivity to short vertical wavelength waves (less than about 10 kin) while th6 imager was most responsive to larger vertical wavelength waves. This study illustrates the significant advantages of combining wind/temperature lidar and multi-wavelength image observations for intrinsic gravity wave measurements.