Horizontal Movement of Polar Mesospheric Clouds Observed From the Himawari‐8 Geostationary Meteorological Satellite

Abstract

AbstractThe horizontal movement of polar mesospheric clouds (PMCs) is examined with data from Geostationary‐Earth‐Orbit (GEO) meteorological satellite Himawari‐8 using a cloud tracking technique. While previous PMC observations from the ground and Low‐Earth‐Orbit satellites have a limitation on local time coverage or field of view, observations from the GEO satellite provide a great opportunity to study the PMC variability with entire local time coverage and a wide field of view. A pattern matching technique is applied to PMC data from the Advanced Himawari Imagers (AHIs) onboard Himawari‐8, and the horizontal movement of PMC along the transverse direction to the line of sight is derived. At the center of field of view of AHI, the tracking velocity represents the zonal movement of PMCs around the latitude of 81.3°N and the longitude of 140.7°E. The horizontal movement shows large oscillations with amplitudes of 10–30 m/s and spectral peaks at periods of 12, 14.8, and 24 h. The mean zonal velocity for the northern summer season of 2018 is about 8 m/s in the westward direction. The characteristics of the tracking winds resemble those of horizontal wind reported by previous studies. This indicates that the horizontal movements of PMC observed by Himawari‐8 are mainly subjected to wind advection.