Simulation of the Quasi-Biennial Oscillation in a general circulation model
Abstract
Simulation of the equatorial stratospheric quasi-biennial oscillation (QBO) is accomplished, using a T42-horizontal resolution, 60-layer general circulation model (GCM), with a scheme of moist convective adjustment. In a previous paper, we succeeded in simulating a QBO in a T21 GCM using a damping time of 20 days for the maximum wavenumber in the fourth-order horizontal diffusion. It was noted that the damping time is a factor of 10 larger than that employed in standard GCMs. In this paper, we explore whether it is possible to use a smaller damping term by going to a finer horizontal resolution. We successfully simulated a QBO using a damping time of 4 days. The period of the simulated QBO is 800 days, being almost the same as that observed. The amplitude of the zonal-wind oscillation is 20 ms-1. However, this is achieved at the expense of much noiser precipitation and the damping time is still a factor of 7 larger than the standard values.
- Publication:
-
Geophysical Research Letters
- Pub Date:
- May 1999
- DOI:
- 10.1029/1999GL900188
- Bibcode:
- 1999GeoRL..26.1307T
- Keywords:
-
- Meteorology and Atmospheric Dynamics: Middle atmosphere dynamics (0341;
- 0342);
- Meteorology and Atmospheric Dynamics: General circulation;
- Meteorology and Atmospheric Dynamics: Numerical modeling and data assimilation;
- Atmospheric Composition and Structure: Middle atmosphere-energy deposition