Numerical Simulation of Sudden Stratospheric Warmings.
Abstract
A mechanistic, quasigeostrophic model with a self consistent calculation of the mean zonal flow was used to numerically simulate sudden stratospheric warmings generated by a single zonal harmonic (m) planetary wave. The development of a warming depends critically on the two factors which govern the transmission of planetary waves to the upper stratosphere: (1) the strength of the westerly winds in the lower stratosphere and (2) the magnitude of wave damping in the same region. Major warmings can only develop when the prewarming lower stratospheric winds are strong. Damping controls the maximum amplitude that a warming can attain and the time constant for its growth rate. Long term integrations with a steady forced m = 1 wave show that the mean flow evolves to a steady, asymptotic state with net cooling in the polar mesosphere from planetary waves. But steady m = 2 forcing leads to multiple generation of warmings which are similar to stratospheric vacillations.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 26, 1979
- Accession Number
- ADA071249
Entities
People
- Darrell F. Strobel
- Mark R. Schoeberl
Organizations
- United States Naval Research Laboratory