OZONE AND TEMPERATURE-CHANGES IN THE STRATOSPHERE FOLLOWING THE ERUPTION OF MOUNT-PINATUBO

Global variations in stratospheric ozone and lower stratospheric temperature are documented for the period 1991-1994, following the eruption of Mount Pinatubo in June 1991. Column ozone measurements are from the total ozone mapping spectrometer instruments on the Nimbus 7 and Meteor 3 satellites, together with solar backscattered ultraviolet data from NOAA 11; these satellite ozone data are validated by comparisons with ground-based Dobson spectrophotometer measurements. Ozone profile data from the halogen occultation experiment and microwave limb sounder instruments on the upper atmosphere research satellite are also analyzed. Satellite temperature data are from the microwave sounding unit channel 4, representing a mean of the 150- to 50-mbar layer. The ozone observations show substantial decreases in column ozone (of order 5-10%) over large regions of the globe; largest losses are observed in northern hemisphere middle-high latitudes during winter-spring of each year (largest in 1992-1993), over southern hemisphere high latitudes in spring 1993, and episodically over the tropics during 1991-1993. Temperatures are anomalously warm (by order 1 K) over 30 degrees N-S for 1 to 2 years following the eruption. Significant cold anomalies are also observed over the northern hemisphere polar cap during summer 1993, a result probably related to the decreased ozone levels throughout 1993.