Combined wind measurements by two different lidar instruments in the Arctic middle atmosphere

[摘要] During a joint campaign in January 2009, the Rayleigh/Mie/Raman (RMR) lidarand the sodium lidar at the ALOMAR Observatory (69° N, 16° E)in Northern Norway were operated simultaneously for more than 40 h,collecting data for wind measurements in the middle atmosphere from 30 up to110 km altitude. As both lidars share the same receiving telescopes, theupper altitude range of the RMR lidar and the lower altitude range of thesodium lidar overlap in the altitude region of ≈80–85 km. Forthis overlap region we are thus able to present the first simultaneous windmeasurements derived from two different lidar instruments. The comparison ofwinds derived by RMR and sodium lidar is excellent for long integration timesof 10 h as well as shorter ones of 1 h. Combination of data from bothlidars allows identifying wavy structures between 30 and 110 kmaltitude, whose amplitudes increase with height. We have also performedvertical wind measurements and measurements of the same horizontal windcomponent using two independent lasers and telescopes of the RMR lidar andshow how to use this data to calibrate and validate the wind retrieval. Forthe latter configuration we found a good agreement of the results but alsoidentified inhomogeneities in the horizontal wind at about 55 km altitude ofup to 20 ms⁻¹ for an integration time of nearly 4 h. Such small-scaleinhomogeneities in the horizontal wind field are an essential challenge whencomparing data from different instruments.

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