Presentation given at COSPAR 2008. Looking at using meteor radar to study atmospheric gravity waves. Covers introduction to the method and then Arctic / Antarctic comparisons and seasonal behaviour
Seasonal variability of gravity waves and tidal/gravity-wave interactions in the Arctic and Antarctic MLT
1. Seasonal variability of gravity waves and tidal/gravity-wave interactions in the Arctic and Antarctic MLT Charlie Beldon & Nick Mitchell Centre for Space, Atmospheric and Oceanic Science Department of Electronic and Electrical Engineering University of Bath [email_address] COSPAR 2008
51. i.e., more gravity-wave activity in spring over Rothera than Esrange less gravity-wave activity in summer over Rothera at greater heights Inter-hemispheric Comparisons
55. Gravity wave scales sizes Meteor radars cannot easily resolve individual waves of short horizontal wavelength (< ~ 1,000 km) or high frequency (periods < ~ 2 hours)
56. Equinoctial minima – filtering of low phase-speed waves Seasonal Cycle - Filtering
57. NB, six routine height gates of 5, 3, 3, 3, 3, 5 km Meteor radar winds January 6, 2007 over Rothera (68 ˚S) Can not easily resolve individual waves of short horizontal wavelength (< ~ 1,000 km) or high frequency (periods < ~ 2 hours)
58. January 6, 2007 over Rothera (68 ˚S) Meteor radar winds NB, six routine height gates of 5, 3, 3, 3, 3, 5 km
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62. Seasonal cycle and short-term variability Rothera (68˚S) Variance (m 2 s -2 ) Variance (m 2 s -2 )