Atmospheric superrotation?

Beginning in 1958 analysis of the atmospheric drag on artificial earth satellites has provided many measurements of the rotation of the earthʹs thermosphere.11Atmospheric rotation is represented by the ratio: Λ=(mean inertial rotation of the atmosphere)/(mean earth rotation). Superrotation occurs when Λ>1.0. s reported that there was a net west-to-east wind ranging from 50 m s−1 to more than 200 m s−1: the so-called superrotation. Although a number of analysts have contributed to these measurements, they have not been confirmed by theoretical models or other types of measurements, which have found (a) more complex wind structures and (b) much smaller speed. aper discusses the satellite drag measurements and methodology, pointing out possible sources of systematic error, including discussion of a simulation. Finally, yet another set of data is presented, benefitting from the insights gained during the last 40 years. The main result of this analysis suggests a mean superrotation of 2% (Λ=1.026±0.01). The larger published values of Λ are assumed to result from subtle unmodelled systematic errors in the earlier data analysis, or indicate that superrotation was larger in the 1960s and 1970s than it was in the 1980s. Progress on this question should include reanalysis of some of the earlier data.