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Vertical distribution of gravity wave potential energy from long‐term Rayleigh lidar data at a northern middle‐latitude site
Author(s) -
Mzé N.,
Hauchecorne A.,
Keckhut P.,
Thétis M.
Publication year - 2014
Publication title -
journal of geophysical research: atmospheres
Language(s) - English
Resource type - Journals
eISSN - 2169-8996
pISSN - 2169-897X
DOI - 10.1002/2014jd022035
Subject(s) - mesosphere , lidar , gravity wave , stratosphere , altitude (triangle) , atmospheric sciences , latitude , mesopause , climatology , middle latitudes , environmental science , rayleigh distribution , geology , gravitational wave , geodesy , rayleigh scattering , physics , remote sensing , geometry , mathematics , astrophysics , optics
In this paper, we use the Rayleigh lidar in order to give an overview of the gravity wave activity at a northern middle‐latitude station at Haute‐Provence Observatory (43.93°N, 5.71°E). In order to have access to perturbations with short time and vertical scales, at least in a statistical sense, we analyze raw lidar signals with a variance method. Sixteen years of lidar data sets are analyzed in this study. The results of the variability, climatology, and seasonal changes are reported. We observe night‐to‐night variability in gravity wave potential energy, which follows a lognormal distribution with a standard deviation ranging between 0.50 and 0.58 (base 10 logarithm). A monthly distribution of gravity waves is also obtained in the upper stratosphere and mesosphere. In the 30–50 km altitude range (the upper stratosphere), an annual cycle is clearly found with a maximum in winter and a minimum in summer. An annual cycle in the lower mesosphere is also observed with maximum in winter. In the upper mesosphere, a semiannual cycle is found at ~75 km. At this altitude, the maximum gravity wave activity occurs in winter and in summer. A more pronounced summer maximum is observed (+25%). The summer maximum at Haute‐Provence Observatory in the upper mesosphere is probably due to oblique propagation. Looking at the seasonally averaged profiles, it is possible to observe the preferential altitudes of energy dissipation. Gravity waves are dissipating above ~70 km during all seasons, but there is relatively little dissipation at lower altitudes.