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Abstract Meteoroids of sub‐milligram sizes burn up high in the Earth's atmosphere and cause streaks of plasma trails detectable by meteor radars. The altitude at which these trails, or meteors, form depends on a number of factors including atmospheric density and the astronomical source populations from which these meteoroids originate. A previous study has shown that the altitude of these meteors is affected by long‐term linear trends and the 11‐year solar cycle related to changes in our atmosphere. In this work, we examine how shorter diurnal and seasonal variations in the altitude distribution of meteors are dependent on the geographical location at which the measurements are performed. We use meteoroid altitude data from 18 independent meteor radar stations at a broad range of latitudes and investigate whether there are local time (LT) and seasonal variations in the altitude of the peak meteor height, defined as the majority detection altitude of all meteors within a certain period, which differ from those expected purely from the variation in the visibility of their astronomical source. We find a consistent LT and seasonal response for the Northern Hemisphere locations regardless of latitude. However, the Southern Hemisphere locations exhibit much greater LT and seasonal variation. In particular, we find a complex response in the four stations located within the Southern Andes region, which indicates that the strong dynamical atmospheric activity, such as the gravity waves prevalent here, disrupts, and masks the seasonality and dependence on the astronomical sources. 

Abstract A new 36.17 MHz all‐sky meteor radar was installed at McMurdo Station Antarctica (77.8°S, 166.7°E) in February 2018 to provide wind measurements in the mesosphere and lower thermosphere (MLT) region (70–120 km). This instrument is the highest latitude meteor radar currently in operation in the southern hemisphere; it joins two other meteor radars within the Antarctic Circle. The radar will provide long‐term continuous wind measurements of the polar region, and contribute to a greater understanding of MLT dynamics. This work describes the radar hardware and its context with other instruments in the region. The paper provides an overview of the spatial and temporal variation in meteor echoes over the observation period of March 2018 through October 2021. It also provides an analysis of the mean winds and solar tides over the first three years of operation; including a description of an observed 12 hr summertime wind oscillation consistent with previously documented observations of a westward propagating 12 hr non‐migrating tide of zonal wavenumber 1.