Recent progress in mesospheric gravity wave studies using nigthglow imaging system

Michael J. Taylor, Utah State University
William R. Pendleton Jr., Utah State University
Pierre-Dominique Pautet, Utah State University
Yucheng Zhao, Utah State University
Chris Olsen, Utah State University
Hema Karnam Surendra Babu, Utah State University
Amauri F. Medeiros, Universidade Federal de Campina Grande
Hisao Takahashi, INPE

Abstract

A variety of optical remote sensing techniques have now revealed a rich spectrum of wave activity in the upper atmosphere. Many of these perturbations, with periodicities ranging from ~ 5 min to many hours and horizontal scales of a few tens of km to several thousands km, are due to freely propagating atmospheric gravity waves and forced tidal oscillations. Passive optical observations of the spatial and temporal characteristics of these waves in the mesosphere and lower thermosphere (MLT) region ( ~ 80-100 km) are facilitated by several naturally occurring, vertically distinct nightglow layers. This paper describes the use of state-of-the-art ground-based CCD imaging techniques to detect these waves in intensity and temperature. All-sky (180º) image measurements are used to illustrate the characteristics of small-scale, short period ( < 1 hour) waves and to investigate their seasonal propagation and momentum impact on the MLT region. These results are then contrasted with measurements of mesospheric temperature made using a new temperature mapping imaging system capable of determining induced temperature amplitudes of a large range of wave motions and investigating night-to-night and seasonal variability in mesospheric temperature.