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We present the derivation of turbulent energy dissipation rate εfrom a total of 522 days of observations with the Middle Atmosphere Alomar Radar SYstem (MAARSY) mesosphere–stratosphere–troposphere (MST) radar runningtropospheric experiments during the period of 2010–2013 as well as withballoon-borne radiosondes based on a campaign in the summer 2013.Spectral widths are converted to ε after the removal of thebroadening effects due to the finite beam width of the radar. With thesimultaneous in situ measurements of ε with balloon-borneradiosondes at the MAARSY radar site, we compare the εvalues derived from both techniques and reach an encouraging agreement between them. Usingall the radar data available, we present a preliminary climatology ofatmospheric turbulence in the UTLS (upper troposphere and lowerstratosphere) region above the MAARSY site showing a variability of more than 5 orders ofmagnitude inherent in turbulent energy dissipation rates. Thederived ε values reveal a log-normal distribution with a negativeskewness, and the ε profiles show an increase with height which isalso the case for each individual month. Atmospheric turbulence based on ourradar measurements reveals a seasonal variation but no clear diurnal variationin the UTLS region. Comparison of ε with the gradient Richardsonnumber Ri shows that only 1.7 % of all the data withturbulence occur under the condition of Ri < 1 and that the valuesof ε under the condition of Ri < 1 are significantlylarger than those under Ri > 1. Further, there is a roughly negativecorrelation between ε and Ri that is independent of the scaledependence of Ri. Turbulence under active dynamical conditions(velocity of horizontal wind U > 10 m s−1) is significantly stronger than under quiet conditions(U < 10 m s−1). Last but not least, the derived ε valuesare compared with the corresponding vertical shears of background windvelocity showing a linear relation with a corresponding correlationcoefficient r = 58 % well above the 99.9 % significance level. Thisimplies that wind shears play an important role in the turbulence generationin the troposphere and lower stratosphere (through the Kelvin–Helmholtzinstability)

Derivation of turbulent energy dissipation rate with the Middle Atmosphere Alomar Radar System (MAARSY) and radiosondes at Andøya, Norway