Horizontal Correlation Functions of Wind Fluctuations in the Mesosphere and Lower Thermosphere
Permanent link
https://hdl.handle.net/10037/30639Date
2023-03-01Type
Journal articleTidsskriftartikkel
Peer reviewed
Author
Poblet, Facundo L.; Vierinen, Juha; Avsarkisov, Victor; Conte, J. Federico; Charuvil Asokan, Harikrishnan; Jacobi, Christoph; Chau, Jorge L.Abstract
Measurements of kinetic energy in vortical and divergent fluctuations in the mesosphere and
lower thermosphere can be used to study stratified turbulence (ST) and gravity waves. This can be done using
horizontal correlation functions of the fluctuating component of velocity. This study introduces a novel method
for estimating these correlation functions using radars that observe Doppler shifts of ionized specular meteor
trails. The technique solves the correlation functions directly on a longitudinal-transverse-up coordinate system,
assuming axial symmetry. This procedure is more efficient and leads to smaller uncertainties than a previous
approach. The new technique is applied to a year-long data set from a multistatic specular meteor radar network
in Germany, to study the annual variability of kinetic energy within turbulent fluctuations at 87–93 km of
altitude. In monthly averages, the kinetic energy is found to be nearly equipartitioned between vortical and
divergent modes. Turbulent fluctuations maximize during the winter months with approximately 25% more
energy in these months than at other times. The horizontal correlation functions are in agreement with the
inertial subrange of ST, exhibiting a 2/3 power law in the horizontal lag direction, with an outermost scale of
ST to be about 380 km. This suggests that horizontal correlation functions could be used to estimate turbulent
energy transfer rates.
Publisher
WileyCitation
Poblet, Vierinen, Avsarkisov, Conte, Charuvil Asokan, Jacobi, Chau. Horizontal Correlation Functions of Wind Fluctuations in the Mesosphere and Lower Thermosphere. Journal of Geophysical Research (JGR): Atmospheres. 2023;128(6)Metadata
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