Diurnal Oscillations of the Tropospheric Wind Field above a Low-Level Jet

Abstract

An hypothesis is given for the cause of the observed diurnal oscillations in the mid- and upper-tropospheric wind field that occur in association with oscillations of the boundary layer wind field and low-level, nocturnal jet occurrences. A simple mathematical model of the middle and upper troposphere is solved using perturbation techniques subject to the condition that the three-dimensional velocity is continuous at a plane separating the boundary layer from the atmosphere above, and the vertical motion is zero at the tropopause height. Theoretical results are presented which show good agreement with previously published wind data from the surface to the region of the tropopause.