Abstract

Rocketsonde temperatures for the 26–35 km layer have been compared with nearby radiosonde temperatures at 10 mb (30 km), confirming that during the early 1970s the rocketsonde temperatures cooled appreciably relative to radiosonde temperature apparently due mostly to changes in rocketsonde type. Accordingly, rocketsonde-derived temperature variations cannot be considered representative until at least 1973. Temperature variations during 1973–85 have been determined from mainly western hemisphere rocketsonde data for 26–35, 36–45 and 46–55 km layers of north polar, north temperate, north subtropical and equatorial zone as well as the 26–55 km layer as a whole and the western hemisphere as a whole. Based on linear regression, during this interval western hemisphere temperatures decreased by about 0.5°, 1.5° and 2.5°C/10 yr in the 26–35, 36–45 and 46–55 km layer respectively, the latter two decreases significant at the 5% level. However, radiosonde temperatures in the low stratosphere suggest that this rocketsonde-derived cooling is not representative of the entire Northern Hemisphere, and radiosonde temperatures at 30 km indicate an uncertainty with regard to temperature changes at this height even in the western hemisphere. Rocketsonde-derived changes in seasonal temperature have been similar, though in the 26–35 and 36–45 km layers the cooling has been somewhat greater in autumn. The temperature in the 46–55 km layer has tended to vary in phase with sunspot number, but the short record makes the relation an uncertain one.

This content is only available as a PDF.