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An unusual mesospheric bore event observed at high latitudes over Antarctica
Author(s) -
Nielsen K.,
Taylor M. J.,
Stockwell R. G.,
Jarvis M. J.
Publication year - 2006
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2005gl025649
Subject(s) - airglow , geology , latitude , wavelength , atmospheric sciences , gravity wave , low latitude , front (military) , high latitude , climatology , geophysics , geodesy , wave propagation , physics , optics , oceanography
All‐sky CCD observations of short‐period mesospheric gravity waves have been made from Halley Station, Antarctica (76°S, 27°W). On 27 May, 2001, an unusual wave event exhibiting several features characteristic of a “bore” was observed in the OH, Na, and O 2 nightglow emissions. Mesospheric bores are rare wave events that have previously been observed at mid‐ and low‐latitudes. This event was particular interesting as: (1) it initially appeared as a single, high contrast, linear front, accompanied by a sharp enhancement in intensity in all three emissions, (2) a number of trailing wave crests were observed to form with a measured growth rate of 6.6 waves/hr, and (3) the wave pattern exhibited unusual dynamics with significant variability in the observed phase speed and a reduction in the horizontal wavelength by ∼50% over a 1‐hr period. The location of Halley and the observed propagation suggests a ducted wave consistent with current bore models.