Changes in Tropospheric and Stratospheric Global Temperatures, 1958-1988

Abstract

Based on a network of 63 radiosonde stations distributed fairly evenly around the world, the global tropospheric temperature in 1988 was the maximum observed since the beginning of the record in 1958,0.02°C warmer than 1983, 0.06°C warmer than 1987, and about 0.16°C warmer than 1980 and 1981. The global tropospheric temperature is indicated to have increased by a significant 0.2°C between 1958–72 and 1974–88, but with most of the warming in the Southern Hemisphere and the north temperate zone even cooling slightly. Between these two intervals there was cooling in all climatic zones in the tropopause layer, the cooling of 0.2–O.3°C being significant in both hemispheres. The global low stratosphere cooled by more than 1.5°C following the 0.5°C warming occasioned by the El Chichón volcanic eruption, with most of the cooling in the Southern Hemisphere and, in particular, in the south polar zone (Antarctic “ozone hole” phenomenon). Emphasized is the strong influence of El Niño on global tropospheric temperatures about two seasons later, and because of the El Niño in 1987, the need for caution in relating the record warmth of 1988 to any greenhouse effect. Discussed is the extent to which these tropospheric and stratospheric temperature changes support the presumption that a greenhouse effect is already being observed.