High-time resolution analysis of meridional tides in the upper mesosphere and lower thermosphere at mid-latitudes measured by the Falkland Islands SuperDARN radar

Abstract. Solar tides play a major role in the dynamics of the upper mesosphere and lower thermosphere (MLT). Hence, a comprehensive understanding of these tides is important for successful modelling of the MLT region. Most ground-based observations of tidal variations in the MLT have been from meteor radar measurements with a temporal resolution of 1 hr. Here, we take a different perspective on these tidal variations using high-resolution 1-min neutral wind measurements from the Falkland Islands SuperDARN radar. This analysis shows that these higher-resolution data can be used to identify higher frequency tidal components than are typically observed by meteor radars (up to a heptadiurnal component). It also shows evidence of significant power in these higher frequency components, particularly in the quaddiurnal component, which may be particularly suitable for a global analysis using high-resolution SuperDARN neutral wind measurements. The high-resolution analysis also shows evidence of fluctuations with a frequency of 1.5 cycles/day, as well as higher frequency fluctuations, accompanying a quasi-two-day wave. We discuss the limitations of this high-resolution analysis method, and the new opportunities that it may provide. We conclude that higher-resolution SuperDARN neutral wind measurements need to be better exploited in the future, as they provide a complementary way of studying tides and waves in the MLT.