Morphology of turbulence in the polar summer mesopause region during the MIDAS/SOLSTICE campaign 2001

Abstract

Two rocket borne in situ measurements of neutral air turbulence profiles in the polar summer mesosphere were performed during the MIDAS/SOLSTICE campaign in June 2001 from the Andøya Rocket Range (69°N). Both profiles reveal typical energy dissipation rates for summer conditions with maximum values of ∼1000mW/kg near the mesopause corresponding to heating rates of ∼100 K/d. The morphology of the turbulent layers in both flights is very different. In the first flight almost the complete altitude range from 81 to 90 km is filled with turbulence. With the help of accompanying high resolution wind measurements with foil clouds we identify dynamical instabilities as sources for these turbulent events. The second flight shows only two single turbulent layers of 1 km thickness. A dynamical instability near the upper turbulent layer also suggests that an unstable flow created this turbulent event.