Intercomparison of middle-atmospheric wind in observations and models
Abstract. Wind profile information throughout the entire upper stratosphere and lower
mesosphere (USLM) is important for the understanding of atmospheric dynamics
but became available only recently, thanks to developments in remote sensing
techniques and modelling approaches. However, as wind measurements from these
altitudes are rare, such products have generally not yet been validated with
(other) observations. This paper presents the first long-term intercomparison
of wind observations in the USLM by co-located microwave radiometer and lidar
instruments at Andenes, Norway (69.3 ∘  N, 16.0 ∘  E). Good
correspondence has been found at all altitudes for both horizontal wind
components for nighttime as well as daylight conditions. Biases are mostly
within the random errors and do not exceed 5–10 m s −1 , which is less than 10 %
of the typically encountered wind speeds. Moreover, comparisons of the
observations with the major reanalyses and models covering this altitude
range are shown, in particular with the recently released ERA5, ECMWF's
first reanalysis to cover the whole USLM region. The agreement between
models and observations is very good in general, but temporally limited
occurrences of pronounced discrepancies (up to 40 m s −1 ) exist. In the
article's Appendix the possibility of obtaining nighttime wind information
about the mesopause region by means of microwave radiometry is investigated.