Comparison of winds measured by MU radar and Fabry–Perot interferometer and effect of OI5577 airglow height variations

• Published in: Journal of atmospheric and solar-terrestrial physics Vol. 66; no. 6; pp. 573 - 583
• Main Authors: Fujii, Junsuke, Nakamura, Takuji, Tsuda, Toshitaka, Shiokawa, Kazuo
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Oxford Elsevier Ltd 01.04.2004; Elsevier
• Subjects: Airglow; Atmospheric gravity waves; Earth, ocean, space; Exact sciences and technology; External geophysics; Fabry–Perot interferometer; Mesopause; Meteor radar; Physics of the high neutral atmosphere; Physics of the ionosphere; Physics of the magnetosphere; Remote sensing; Far East; Japan; Fabry–Perot interferometer; Mesopause; Meteor radar; Atmospheric gravity waves; Remote sensing; Airglow; time variations; Night; Wind velocity; remote sensing; Fabry-Perot interferometer; Asia; meteors; Gravity wave; winds; Fabry Pérot interferometer; Height; Upper atmosphere; Diffusion coefficient; Atmospheric wave
• ISSN: 1364-6826; 1879-1824
• DOI: 10.1016/j.jastp.2004.01.010

We have compared wind velocities around mesopause height measured by the middle and upper atmosphere (MU) radar (meteor mode) and OI (5577) airglow observation by an Fabry–Perot Interferometer (FPI), at Shigaraki (34.8° N, 136.1° E) , Japan, on November 13/14, 1999. When we assume the airglow height is constant throughout the night, it was difficult to find a single height exhibiting small r.m.s. differences between the two methods for both eastward and northward wind velocities. However, in the case we introduce a time variation of the airglow height due to a large-scale gravity wave activity, we have found very small r.m.s. wind difference: The assumptions are of the airglow height variation with an amplitude of 1.5 km , a period of 5.7 h and a linear trend of −0.19 km/h having the average height of 92.8 km . Further analysis of time and height variations of the winds and diffusion coefficients measured by the MU radar indicated that a gravity wave with a very similar structure predicted in the above comparison between the FPI and meteor winds has been detected as a dominant wave component. Thus, we conclude that the existence of a gravity wave which can change the airglow height will lead to differences in wind velocities observed with FPI and radar techniques.