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Mesospheric anomalous diffusion during noctilucent cloud scenarios

Abstract. The Andenes specular meteor radar shows meteor trail diffusion rates increasing on average by
about 10 % at times and locations where a lidar observes noctilucent
clouds (NLCs). This high-latitude effect has been attributed to the presence
of charged NLC after exploring possible contributions from thermal tides. To
make this claim, the current study evaluates data from three stations at
high, middle, and low latitudes for the years 2012 to 2016 to show that NLC
influence on the meteor trail diffusion is independent of thermal tides. The
observations also show that the meteor trail diffusion enhancement during NLC
cover exists only at high latitudes and near the peaks of NLC layers. This
paper discusses a number of possible explanations for changes in the regions
with NLCs and leans towards the hypothesis that the relative abundance of
background electron density plays the leading role. A more accurate model of
the meteor trail diffusion around NLC particles would help researchers
determine mesospheric temperature and neutral density profiles from meteor
radars at high latitudes.
