Efficient Radiative Transfer Computations in the Atmosphere.
Abstract
An efficient longwave radiation transfer band model was developed and applied to the MIT Stratospheric General Circulation Model (GCM). The band model is a revised version of models by Ramanathan (1976) and by Alimandi and Viscounti (1979). It is validated by comparison with work by Dopplick (1971), Slade (1969) and by Park and London (1974). The band model produced pole-to-pole heating gradients up to 9 deg K/day compared with Newtonian heating gradients of 1-2 deg K/day used previously in the GCM. In 5 day-model integrations, the band model sharpened erroneous temperature gradients in the GCM when compared with the Newtonian heating scheme. Poleward eddy heat fluxes appear to be too weak in the low-resolution, 6 wave spectral GCM to balance the heating gradients of the band model. An 18-wave spectral GCM is planned by the MIT stratospheric working group. With the band model, global heating rates up to 3 deg K/day are noted. Such global heating rates cannot be sustained in the atmosphere. Methods to achieve global heating balance are explored. The most straight forward method is to set the Horizontal-averaged temperatures of the GCM equal to the radiative equilibrium temperatures of the band model. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1981
- Accession Number
- ADA107289
Entities
People
- Charles Robert Posey Ii
Organizations
- Air Force Institute of Technology