Simulation of atmospheric circulation disturbances under anomalies in sea surface temperature and incident solar radiation

Numerical experiments with a global spectral model T21L15 are described. The model is truncated to 21 spherical harmonics, has 15 sigma levels in the vertical, and includes parametrization schemes for the basic physical processes in the atmosphere. In all experiments, the model was integrated for 10 years. A control experiment is compared with two anomalous experiments. The incident solar radiation corresponding to April 1 of the model calendar was held fixed in one of the anomalous experiments. In the other anomalous experiment, the sea surface temperature corresponding to April 1 was held fixed. The numerical results for July and August are analyzed. Atmospheric disturbances in the sea level pressure, stationary pressure waves, wind speed at 200 hpa, near-surface temperature, and precipitation amounts produced in the anomalous experiments are examined.