Original scientific paper
The ABL due to a Mountain Pass and Coriolis Effect
B. Grisogono
orcid.org/0000-0002-3732-9710
; Dept. of Geophysics, Fac. of Sci. & Math., Horvatovac bb, Univ. of Zagreb, 10000 Zagreb, Croatia
L. Enger
; Dept. of Earth Sci., Villav. 16, Univ. of Uppsala, S-75646 Uppsala, Sweden
D. Belušić
; Dept. of Geophysics, Fac. of Sci. & Math., Horvatovac bb, Univ. of Zagreb, 10000 Zagreb, Croatia
Abstract
Idealized airflow over a mountain with a pass is studied using a numerical mesoscale model with a trustful higher-order turbulence parameterization scheme. A uniformly stratified inflow of 8 m/s over mountain, 100km x 20km x 1km, yields Froude number 0.6, while Rossby number along the flow ranges from 7.6 to infinity. A pass drops the mountain top to ~ 400m locally increasing Froude number and modifying the overall wave breaking and the ABL. In the presence of the Earth rotation, f ≠ 0, which already breaks the lee-side flow symmetry, the pass induces additional variations in the ABL extending far from the mountain. Both, the rotation and the pass, alter the low-level jet structure and the specific humidity field. This mesoscale process may stretch to synoptic scale within a reasonable time, say 15-25h, only when the rotation is included. Otherwise, a somewhat similar process with f=0 might take unreasonably long time.
Keywords
Wave-breaking; Coriolis; Low-level jet; Turbulence; Mountain waves; Numerical model
Hrčak ID:
64589
URI
Publication date:
15.12.2005.
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