Fig. 10From: Relationship between topography, tropospheric wind, and frequency of mountain waves in the upper mesosphere over the Kanto area of JapanHorizontal wind speed component, U [m/s], projected in the wind direction at an altitude of 1,000 m from the ground. The red line shows the mean horizontal wind data from 21:00 to 27:00 JST on 6 January 2019. Black lines show the nightly mean (18:00–27:00 JST) wind profiles projected in the wind direction at an altitude of 1000 m from the ground on 22 clear nights in January 2019Back to article page