Stratospheric Temperature Change as a Function of Height and Sunspot Number during 1972–89 Based on Rocketsonde and Radiosonde Data

Abstract

Based on linear regression analysis applied to temperatures at 6 rocketsonde and 12 radiosonde stations mostly in the western half of the Northern Hemisphere, between 1972 and 1989 the temperature changed by nearly −0.5°C/decade in the low stratosphere, close to −1.6°C/decade in the high stratosphere, and by approximately −2.0°C/decade in the stratosphere layer. In the middle stratosphere the temperature is indicated to have changed by −0.3°C/decade according to the radiosonde data but by about -0.9°C/decade according to the rocketsonde data. The reason for this discrepancy is still uncertain. The cooling has been greatest in winter, except in the middle stratosphere where it has been similar in winter and autumn. The correlation between annual values or sunspot number and temperature has been best in the middle stratosphere (0.83), but even this correlation is not significant at the 5% level due to the short record and the considerable serial correlation in the date. In the middle and high stratosphere and stratopause layer there has been an increase in temperature of about 0.8°C for an increase in sunspot number of 100, and in the low stratosphere an increase in temperature about half as great.