Abstract

We present direct observations of the semidiurnal lunar tide zonal winds at 260 km and 350 km during low solar activity in 2007-2008, and 2010-2011. The migrating semidiurnal lunar tide, or M₂, is a global feature with amplitudes of about 10 m s⁻¹ at equatorial latitudes, and 20 m s⁻¹ at high lat... Show moreWe present direct observations of the semidiurnal lunar tide zonal winds at 260 km and 350 km during low solar activity in 2007-2008, and 2010-2011. The migrating semidiurnal lunar tide, or M₂, is a global feature with amplitudes of about 10 m s⁻¹ at equatorial latitudes, and 20 m s⁻¹ at high latitudes. Amplitude maxima appear twice yearly, between February and April and between August and November. M₂ amplitudes during 2007-2008 are about 20% stronger than those during 2010-2011. These magnitudes are consistent with numerical predictions in WACCM-X. However, only one annual global-scale maximum is simulated during January-March. Show less