Middle atmospheric traveling waves forced by latent and convective heating

Journal Article · Thu Jul 15 04:00:00 EDT 1993 · Journal of the Atmospheric Sciences; (United States)

DOI:https://doi.org/10.1175/1520-0469(1993)050<2180:MATWFB>2.0.CO;2· OSTI ID:6069535

Manzini, E; Hamilton, K ^[1]

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1. Princeton Univ., NJ (United States)

The excitation and propagation of equatorial planetary waves and inertia-gravity waves are studied by comparing simulations from the comprehensive GFDL troposphere-stratosphere-mesosphere SKYHI general circulation model (GCM) and from a linear primitive equation model with the same domain and numerical resolution. The basic state of the linear model is time dependent and is derived from the mean zonal wind and temperature obtained from a simulation with the full SKYHI model. The latent and convective heating fields of this integration are used as the forcing for the linear model in a parallel simulation. The wavelength and frequency characteristics of the prominent vertically propagating equatorial Kelvin and Rossby-gravity waves are similar in the linear model and in SKYHI. Amplitudes are similar in the lower stratosphere, indicating that the latent and convective heating is the dominant mechanism producing equatorial wave activity in the GCM. The amplitude of these waves in the upper stratosphere and mesosphere is larger in the linear model than in SKYHI. Given that the linear and SKYHI models have comparable radiative damping and horizontal subgrid scale diffusion, it appears that the wave amplitudes in SKYHI are limited by nonlinear saturation, possibly involving the subgrid-scale vertical mixing. At low latitudes the linear model reproduces the flux of upward-propagating inertia-gravity waves seen in the full model. The results show a significant fraction of the inertia-gravity wave activity found in the midlatitude mesosphere of the SKYHI model can be accounted for by tropical convective heating. The global-scale Rossby normal modes seen in observations were identified in the analyses of westward-propagating planetary waves in both models. They are of realistic amplitude in the SKYHI simulation but are weaker in the linear model. The latent and convective heating is not the main source of excitation for the Rossby normal modes. 48 refs., 21 figs., 1 tab.

• OSTI ID: 6069535
• Journal Information: Journal of the Atmospheric Sciences; (United States), Journal Name: Journal of the Atmospheric Sciences; (United States) Vol. 50:14; ISSN 0022-4928; ISSN JAHSAK
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
540110*
COMPUTERIZED SIMULATION
CONVECTION
EARTH ATMOSPHERE
ENERGY TRANSFER
GENERAL CIRCULATION MODELS
GRAVITY WAVES
HEAT TRANSFER
HEATING
LEVELS
MASS TRANSFER
MATHEMATICAL MODELS
METEOROLOGY
SIMULATION