Effects of topography on the atmospheric energetic in a low-resolution general circulation model

Journal Article · Tue Jul 15 04:00:00 EDT 1986 · J. Atmos. Sci.; (United States)

DOI:https://doi.org/10.1175/1520-0469(1986)043<1535:TEOTOT>2.0.CO;2· OSTI ID:6834445

Ni, Y Q; Otto-Bliesner, B L; Houghton, D D

An analysis is made of the effect of orography on the atmospheric energetics in a low-resolution general circulation model to determine the temporal and scale dependency of these effects. The numerical model is a global, spectral, primitive equation model of the atmosphere with five equally spaced sigma levels in the vertical and triangular truncation at wavenumber 10 in the horizontal. A one-year seasonal simulation of the general circulation without mountains is compared to the results from a five-year seasonal simulation of the general circulation with mountains. The statistical significance of the topographic effects is evaluated by comparing them to magnitudes of model interannual variability determined from the five-year control simulation. A small, but important, portion of the changes due to topography are significant. At northern extratropical latitudes, the increases of eddy activities and baroclinic instability in summer resulting from incorporation of the effect of the mountains give rise to significantly increased eddy components of atmospheric energetics and the conversion from eddy available potential energy to eddy kinetic energy. These increases are generally present and significant at each wavenumber and for the overall stationary component. In winter, topography significantly increases the zonal kinetic energy and dissipation. Examination of the individual zonal spectral components for winter reveals that topography increases long-wave energies and their transfer, but with proportional decreases at medium waves, resulting in little change in the total eddy components. A similar compensation occurs between the stationary and transient components of the heat transport. Less pronounced topographic features at tropical and southern extratropical latitudes result in few significant changes due to topography.

• Research Organization: Univ. of Wisconsin, Madison
• OSTI ID: 6834445
• Journal Information: J. Atmos. Sci.; (United States), Journal Name: J. Atmos. Sci.; (United States) Journal Issue: 14 Vol. 43:14; ISSN JAHSA
• Country of Publication: United States
• Language: English

Related Subjects

500100* -- Environment
Atmospheric-- Basic Studies-- (-1989)
54 ENVIRONMENTAL SCIENCES
ATMOSPHERIC CIRCULATION
ENERGY BALANCE
ENVIRONMENTAL EFFECTS
GENERAL CIRCULATION MODELS
GEOGRAPHICAL VARIATIONS
GLOBAL ASPECTS
LATITUDE EFFECT
MATHEMATICAL MODELS
MOUNTAINS
SEASONAL VARIATIONS
SENSITIVITY ANALYSIS
TOPOGRAPHY
VARIATIONS