ISSN:
1420-9136
Keywords:
Gravity waves
;
turbulence
;
heat transport
;
tracer transport
;
eddy diffusion
;
mesosphere
Source:
Springer Online Journal Archives 1860-2000
Topics:
Geosciences
,
Physics
Notes:
Abstract A review of the important constraints on gravity wave induced diffusion of chemical tracers, heat, and momentum is given. Ground-based microwave spectroscopy measurements of H2O and CO and rocket-based mass spectrometer measurements of Ar constrain the eddy diffusion coefficient for constituent transport (K zz ) to be (1–3)×105 cm2s−1 in the upper mesosphere. Atomic oxygen data also limitsK zz to a comparable value at the mesopause. From the energy balance of the upper mesosphere the eddy diffusion coefficient for heat transport (D H ) is, at most 6×105 cm2s−1 at the mesopause and decreasing substantially with decreasing altitude. The available evidence for mean wind deceleration and the corresponding eddy diffusion coefficient for momentum stresses (D M ) suggests that it is at least 1×106 cm2s−1, in the upper mesosphere. Consequently the eddy Prandtl number for macroscopic scale lengths is 〉3.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00874473
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