Optical measurements of winds and kinetic temperatures in the upper atmosphere

Abstract

was used to determine the thermospheric neutral motions in the auroral zone. These measurements were compared with simultaneously measured ion drifts, obtained with the Chatanika incoherent backscatter radar [73], see Figure 3. This comparison showed that the neutral wind in the evening sector flowed in a generally sunward direction, in correspondence with the direction of ion convection, but opposite to that which would be expected from a consideration of solar heating alone. Further analysis of the 1972-73 data set [74] was presented, together with a modelling study of the auroral momentum equation, to suggest that ion drag was playing an important role in establishing the sunward neutral wind. This work was in accord with independent experimental results using rocket chemical release vapour trail analysis [75-77]. A more recent paper [78] has compared the optical meridional wind measurements made in Alaska during 1972 with determinations of the same parameter made using the Chatanika incoherent scatter radar. Reasonable agreement was found between the two (optical and radar) techniques, both for averaged wind patterns and for simultaneously observed winds from individual nights; this is illustrated in Figure 4. The experimental results from this study were also compared with the predictions of the NCAR-TGCM; the comparison indicated reasonable agreement and was suggestive of a possible heat source poleward of Chatanika.

Dynamics of the Earth's Thermosphere: A Review

“…In this section we review the experimental measurements of neutral winds, temperatures and composition published during the last four years. Recent reviews have been presented on the in‐situ mass spectrometer measurement of composition, temperature and winds [ Spencer and Carignan , 1988], incoherent scatter radar measurement of winds [ Wickwar , 1989; Wickwar et al , 1990], temperatures and atomic oxygen [ Oliver et al , 1988c] and optical measurement of winds and kinetic temperatures [ Hernandez and Killeen , 1988].…”

Review of mesospheric temperature trends

“…Instruments that have been used for the measurement of the hydroxyl rotational temperature include grating spectrographs [e.g., Meinel , 1950; Krassovsky et al ., 1962] and spectrometers [e.g., Myrabo and Harang , 1988], Fabry‐Perot spectrometers [e.g., Hernandez and Killeen , 1988; Greet et al ., 1994], tilting‐filter photometers [e.g., Meriwether , 1975; Scheer , 1987; Takahashi et al ., 1998], and near‐infrared Fourier transform spectrometers [e.g., Turnbull and Lowe , 1983; Mulligan et al ., 1995]. In recent years the Fourier transform spectrometer operating in the region 1200–1650 nm has established itself as the instrument of choice for many groups for a variety of reasons.…”

Morphology of evening sector aurorae in λ557.7‐nm Doppler temperatures

“…More recently, interferometric techniques have been used with an emphasis on determining neutral winds from observed Doppler shifts [ Hernandez and Killeen , 1988]. Investigations of thermospheric dynamics have been made using these techniques ranging from small‐scale studies of specific phenomena [ Rees et al , 1984b] to global‐scale observations [ Killeen et al , 1988].…”