Tides in the mesopause region over Fort Collins, Colorado (41°N, 105°W) based on lidar temperature observations covering full diurnal cycles

Abstract

Eighteen sets of 24-hour continuous lidar temperature observation, well distributed throughout the year, have been analyzed to reveal the mean amplitude and phase of oscillations with 24-, 12-, 8-, and 6-hour periods for four seasons. The amplitude and phase of both 24- and 12-hour components are compared to the prediction of the most recent global-scale wave model (GSWM-00). The variability of diurnal and semidiurnal oscillations is examined by comparing the amplitude and phases of each observed day in autumn, winter, and spring. Even with the limited data sets reported here, surprisingly good general agreement between the observed and model tidal phases can be established, implicating the prevalence of migrating diurnal and semidiurnal tides. Compared to the diurnal and semidiurnal phases, which typically show clear downward phase progression, the 8- and 6-hour components exhibit small amplitude and show unorganized phase propagation as a function of altitude. The advantage of having coverage over complete diurnal cycle and entire mesopause altitudes as demonstrated here would hopefully stimulate future tidal studies with lidar temperature, and zonal and meridional wind observations Copyright 2002 by the American Geophysical Union.