Climatic Changes and Variations: A Geophysical Problem

Abstract

The morphology of, and the physical factors that control, the seasonal changes in global free air temperature and sea surface temperature are discussed. Non-seasonal tropical free air temperature changes are related to preceeding changes in tropical sea surface temperature and to volcanic aerosol while the tropical sea surface temperature itself is related to changes in surface pressure which characterize the Southern Oscillation. Zonal wind variations at low latitudes accompany the latter variations. The main variability in tropospheric temperature at high latitudes is characterized by the “Greenland seesaw”. The injection of volcanic aerosol by the eruption of Mt. Agung in March 1963 into the stratosphere gives rise to temperature increases of up to 5°C in the stratosphere and cooling of 1°C in the troposphere. The third major climatic signal in the recent record—the so called “Biennial oscillation”is also briefly reviewed.