Sodium lidar-observed strong inertia-gravity wave activities in the mesopause region over Fort Collins, Colorado (41°N, 105°W)

This data set reveals the significant inertia-gravity wave activities with a period of ~18 hours, which are strong in both wind components since UT day 338 (second day of the campaign), and weak in temperature and sodium density.

The considerable variability of wave activities was observed with both wind amplitudes growing up to ~40 m/s at 95-100 km in day 339 and then decreasing dramatically in day 340. We also found that the sodium density wave perturbation is correlated in phase with temperature perturbation below 90 km, and ~180° out of phase above. Applying the linear wave theory, we estimated the wave horizontal propagation direction, horizontal wavelength, and apparent horizontal phase speed to be ~25° south of west, ~1800 ± 150 km, and ~28 ± 2 m/s, respectively.