Simulations of linear and nonlinear disturbances in the stratosphere
Abstract
The dynamics of linear and nonlinear, large-scale disturbances generated in the stratosphere by a localized perturbation in the troposphere are studied and compared. The perturbation is applied at the lower boundary of a primitive equation model of the stratosphere and mesosphere. The simulations are contrasted with an idealized theoretical model of a nonlinear critical layer. It is suggested that regarding the troposphere as a wavemaker forcing changes in the stratosphere according to the tenets of wave, mean-flow theory is an oversimplification. It is found that, preceding a major warming, the flow is asymmetric about any axis and strong warmings develop through the nonlinear interaction of large, deep vortices associated with a tropospheric asymmetry. Associated changes in zonal mean winds give the appearance of distinct minor and major warmings, though a synoptic view allows systematic changes to be seen which caution against dividing the evolution into separate events.
- Publication:
-
Quarterly Journal of the Royal Meteorological Society
- Pub Date:
- July 1988
- DOI:
- 10.1002/qj.49711448210
- Bibcode:
- 1988QJRMS.114.1063O
- Keywords:
-
- Atmospheric Boundary Layer;
- Atmospheric Models;
- Computerized Simulation;
- Perturbation Theory;
- Stratosphere;
- Meridional Flow;
- Mesosphere;
- Numerical Flow Visualization;
- Planetary Waves;
- Troposphere;
- Zonal Flow (Meteorology)