VHF radar measurements of momentum flux using summer polar mesopause echoes

• Published in: Earth, planets, and space planets, and space, 2018-08, Vol.70 (1), p.1-15, Article 129
• Main Authors: Reid, Iain M., Rüster, Rüdiger, Czechowsky, Peter, Spargo, Andrew J.
• Format: Article
• Language: English
• Subjects: 2. Aeronomy; Density; Doppler radar; Earth and Environmental Science; Earth Sciences; Fluctuations; Flux; Geology; Geophysics/Geodesy; Interferometry; May 2017; Measurement; Mesopause; Meteor radars; Middle atmosphere; Momentum (Mechanics); Momentum flux; Observations; Polar mesosphere summer echoes; Radar; Radar beams; Recent Advances in MST and EISCAT/Ionospheric Studies – Special Issue of the Joint MST15 and EISCAT18 Meetings; Reynolds stress; Summer; Very high frequencies; Very high-frequency radar
• ISSN: 1880-5981; 1343-8832; 1880-5981
• DOI: 10.1186/s40623-018-0902-9

We revisit previously unpublished analysis of observations of the dynamics of the mesopause region over the Norwegian Island of Andøya (69°N, 16°E) made during a 1-week period in summer 1987 during the Middle Atmosphere Cooperation-Summer in Northern Europe (MAC-SINE) campaign using the mobile SOUSY VHF (53.5 MHz) Doppler radar operating in a six-beam mode. We do this in the light of: (1) more recent developments in the measurement of the components of the density-normalized Reynolds stress tensor using meteor radars, and with medium-frequency partial reflection radars using the hybrid Doppler interferometric technique, and (2) satellite measurements of the absolute upward flux of horizontal momentum. We consider of the density-normalized total upward flux of horizontal momentum u ′ w ′ ¯ + v ′ w ′ ¯ for the 83–90 km height interval. Values of the component of the density-normalized flux for the 6 min to 12.8 h period range, after the tidal components have been removed, and the effects of the aspect sensitivity on the radar beam look directions have been accounted for vary between 5 m 2  s −2 below 86 km and 13 m 2  s −2 above 86 km. The major contribution is from the 6 to 12.8 h period range. The results of the analysis have implications for meteor radar estimates of momentum flux and also for Doppler radar measurements of the same term in the presence of aspect-sensitive scattering.