A preliminary estimate of inertia effects in a bulk model of katabatic wind

• Main Authors: Tokio Kikuchi, Yutaka Ageta
• Format: Report
• Language: English
• Published: Faculty of Sciences, Kochi University 1989
• Subjects: East Antarctica; Mizuho; Mizuho Plateau; Sastrugi; Antarc*; Antarctica; Ice Sheet; Polar meteorology and glaciology; Proceedings of the NIPR Symposium on Polar Meteorology and Glaciology
• Online Access: https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=3565; http://id.nii.ac.jp/1291/00003565/; https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=3565&item_no=1&attribute_id=18&file_no=1

Observed sastrugi orientations showed considerable deviation from a bulk theory of katabatic wind in lee sides of troughs in ice sheet undulations of which the wavelength is about 400km on the Mizuho Plateau, East Antarctica. The effect of the inertia term which may account for the deviations but is often neglected in the equation of motion for katabatic wind is estimated with the perturbation method. A sinusoidally undulating slope with ridges and troughs is assumed for the model calculation instead of an infinite flat slope for the inertiafree model. The calculated results, in a typical inversion, suggest that the inertia term is significant if the wavelength of the undulations is smaller than about 200km while the effect of the undulations can be neglected if the wavelength is smaller than about 50km. Observed variability in the wind direction in the lee of the troughs may be accounted for by the effect of the inversion height which enhances the inertia effect.