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Large amplitude perturbations in mesospheric OH Meinel and 87‐Km Na lidar temperatures around the autumnal equinox
Author(s) -
Taylor M. J.,
Pendleton W. R.,
Liu H.L.,
She C. Y.,
Gardner L. C.,
Roble R. G.,
Vasoli V.
Publication year - 2001
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 - 10.1029/2000gl012682
Subject(s) - equinox , mesosphere , atmospheric sciences , lidar , environmental science , troposphere , seasonality , atmospheric tide , latitude , gravity wave , atmospheric wave , stratopause , perturbation (astronomy) , thermosphere , ionosphere , climatology , geology , stratosphere , physics , geodesy , remote sensing , geophysics , wave propagation , statistics , mathematics , quantum mechanics
Two high‐precision CEDAR instruments, an OH Mesospheric Temperature Mapper (MTM) and a Na Temperature Lidar, have been used to investigate seasonal variability in the mid‐latitude temperature at ∼87 km altitude over the western USA. Here we report the observation of a large perturbation in mesospheric temperature that occurs shortly after the autumnal equinox in close association with the penetration of planetary‐wave energy from the troposphere into the mesosphere. This perturbation has been observed on three occasions and exhibits a departure of up to ∼25–30 K from the nominal seasonal trend during a disturbed period of ∼2 weeks. Such behavior represents a dramatic transient departure from the seasonal trend expected on the basis of current empirical models. These novel results coupled with a recent TIME‐GCM modeling study [Liu et al., 2000] provide important insight into the role of planetary waves in mesospheric variability during the equinox periods.