Abstract
The polar summer mesosphere is the Earthâ\euro™s coldest region,
allowing the formation of mesospheric ice clouds. These ice clouds
produce strong polar mesospheric summer echoes (PMSE) that are used as
tracers of mesospheric dynamics. Here we report the first observations
of extreme vertical drafts ($\pm$50 ms$^{-1}$)
in the mesosphere obtained from PMSE, characterized by velocities more
than five standard deviations larger than the observed vertical wind
variability. Using aperture synthesis radar imaging, the observed PMSE
morphology resembles a solitary wave in a varicose mode, narrow along
propagation (3–4 km) and elongated ($>10$ km) transverse
to propagation direction, with a relatively large vertical extent
($\sim$13 km). These spatial features are similar to
previously observed mesospheric bores, but we observe only one crest
with much larger vertical extent and higher vertical velocities.