Factors Controlling Free Air and Ocean Temperature of the Last 30 Years and Extrapolation to the Past

Abstract

Relationships between global sea surface temperature, tropospheric free air temperature and oceanic surface wind patterns are explored. Data for the past 30 years show that tropical free air temperature changes are jointly related to preceding sea surface temperature changes and to stratospheric aerosol which varies with volcanic activity. Global sea surface temperature patterns show two principal modes: El Nino, which changes from a negative to a positive phase in less than one year; and the cooling trend which began in the middle 1960’s and was associated with drought in the Sahel. High latitude oceanic cooling is related to surface wind pattern changes which alter oceanic currents and to changes in energy absorbed by the Indian Ocean which is normally passed on to the Atlantic. The idea of an optimum oceanic energy flow vector is coined, this being the pattern of the curl of the surface wind stress. This pattern is shown to be different for wet and dry years in the Sahel. The pattern would also have changed during the last Ice Age as large-scale waves forced by the fixed mountain and variable ice topography interfered. These changes in the orientation of the oceanic energy flow vector may have accounted for the abrupt environmental changes observed in northwest Europe.