Wind shear rotary spectra in the atmosphere

Abstract

In this paper we present the first rotary spectra of the horizontal wind shear measured in the stratosphere with a resolution of 25m. A low frequency gravity wave propagating upward with a vertical wavelength of ≈ 1000 m is clearly identified. This result is quite consistent with many previous observations and may explain why the horizontal velocity spectra may be biased and indicates a power variation law versus vertical wave number steeper than those of both temperature and vertical velocity. Nevertheless, around the small vertical wavelengths (100 m), the asymptotic slope of temperature and horizontal velocity spectra are both close to ‐3 and so in better agreement with the saturated model predictions.