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

Abstract

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.

Observational evidence of wave ducting and evanescence in the mesosphere

“…The imager was designed to investigate gravity wave structures over the 80-100 km range by sequentially recording wave signatures in four nightglow emissions: the NIR OH and 02 band emissions and the OI (557.7 nm) and Na (589.2 nm) line emissions. A brief description of the system is given by Taylor et al [1995a]. The camera consists of a thermoelectrically cooled, bare (1024 x 1024 pixel), chargecoupled device (CCD) of high quantum efficiency, ---80% at visible and ---50% at NIR wavelengths.…”

Climatology and modeling of quasi‐monochromatic atmospheric gravity waves observed over Urbana Illinois

“…These are smallscale waves seen in the airglow layers between 80 and 105 km and which have observed horizontal phase speeds much less than 100 m/s and periods typically less than a few tens of minutes [e.g., Taylor et al, 1995aTaylor et al, , 1995bWu and Killeen, 1996; periods of typically between 5 and 20 min. When freely propagating and not ducted or trapped, these waves would be expected to travel only a few hundred kilometers from their source in the troposphere to where they are observed near the mesopause in airglow observations.…”

Utilizing riometry to observe gravity waves in the sunlit mesosphere

“…[3] The amplitude and direction of gravity waves in the mesosphere can be quantified from the ground by imaging optical emissions from airglow layers [Taylor et al, 1995]. The airglow acts as a tracer for the rarefaction and compression of the atmosphere generated by the waves.…”