Atmospheric Centers of Action as Bridges Between Solar Activity Variations and Regional Climate Change

Author: Sultan Hameed
Affiliation: Institute for Terrestrial and Planetary Atmospheres, Stony Brook University, New York

The large scale centers of high and low pressures known as the atmospheric centers of action (such as the Aleutian Low and the Hawaiian High) are robust features of atmospheric circulation. Variations in global heating rates and circulation cause changes in the intensities and the morphologies of the atmospheric centers of action. In turn, these systems influence atmospheric and oceanic circulations over their respective domains. The centers of action therefore may be considered to act as bridges between variations on the global and regional scales, and could provide a viable link between small magnitude solar activity changes and large changes in local climate. It is known that solar activity induces changes in UV radiation and stratospheric ozone. The primary response of the atmosphere to this direct forcing is in the zonal circulation in the stratosphere. This circulation change induces changes in the centers of action as stationary wave nodes. These changes may be small. However, the changes induced by a center of action in regional circulation and clouds feedback to the center of action. As a result, significant changes in regional climate are observed associated with the solar cycle.