OBSERVATIONS OF TURBULENCE IN CIRRUS CLOUDS

Three daytime flights of the UK Meteorological Office's C-130 aircraft through thick frontal cirrus have been analysed with the aim of deter mining the length scales at which energy is produced, and which mechan isms are responsible. The data was obtained as part of the EUCREX camp aign. It will be shown that the occurrence of turbulence is patchy, we ak and rather 2-dimensional with most turbulent kinetic energy being c ontained in the horizontal wind components. Evidence for the productio n of turbulence by the breaking of Kelvin-Helmholtz waves is found for all of the flights analysed. In one case there also seems to be turbu lence production at a scale of 2 km by convection set up by radiative cloud top cooling.