Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
8948925 | Advances in Space Research | 2018 | 13 Pages |
Abstract
The observational data on OI 630â¯nm thermospheric nightglow from the Indian dip equatorial station, Tirunelveli (8.7°N, 77.8°E geographic, 1.6°N dip latitude) obtained between January 2013 and January 2015 using an All-Sky Airglow Imager (ASAI) are utilized in this work to examine the presence of gravity waves in the thermosphere. Two types of wave signatures were observed: (1) quasi-periodic waves consisting of alternating crests and troughs and (2) single bands of enhanced intensity (SBEI). The phase speed, wavelength and time period of the quasi-periodic waves were in the range of 70-160â¯m/s, 130-575â¯km and 25-75â¯min, respectively, while the phase speed and scale size of the SBEI features were found to be in the range of 150-250â¯m/s and 230-470â¯km, respectively. During equinoxes, quasi-periodic waves propagated towards north-northwest direction, while during winter they were observed to propagate towards northwest, south-southwest and southeast directions.
Keywords
Related Topics
Physical Sciences and Engineering
Earth and Planetary Sciences
Space and Planetary Science
Authors
Sukanta Sau, V. Lakshmi Narayanan, S. Gurubaran, K. Emperumal,