All-sky measurements of short period waves imaged in the OI (557.7 nm), Na(589.2 nm) and near infrared OH and O2(0,1) nightglow emissions during the ALOHA-93 campaign, Geophys. Res. Lett., 22, 2833Lett., 22, , 1995 Abstract. As part of the ALOHA-93 campaign a high performance all-sky CCD imaging system was operated at Haleakala Crater, Maui, to obtain novel information on the properties and sources of short period gravity waves over an extended height range -80-100 kin. Sequential observations of the near infrared OH and O2(0,1) bands and the visible wavelength OI(557.7 nm) and Na(589.2 nm) line emissions have enabled a unique comparison of the morphology and dynamics of the wave motions and their occurrence frequency at each emission altitude to be made. Two major findings are: (a) the detection of significanfly higher amounts of wave structure at OI altitudes (-96 lena) compared with that in the OH emission (-87 kin) and (b) the discovery of an unusual morphology, small-scale wave pattern that was most conspicuous in the OI emission and essentially absent at OH heights. These data provide strong evidence for the presence of ducted wave motions in the lower thermosphere.

An investigation of intrinsic gravity wave signatures using coordinated lidar and nightglow image measurements, Geophys. Res. Lett., 22, 2853Lett., 22, , 1995 Abstract. 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.

No abstract