Estimating the impact of the 1991 Pinatubo eruption on mesospheric temperature by analyzing HALOE (UARS) temperature data

Abstract

Abstract. The Mt. Pinatubo eruption in 1991 had a severe impact on the Earth system, with a well-documented warming of the tropical lower stratosphere and a general cooling of the surface. This study focuses on the impact of this event on the mesosphere by analyzing solar occultation temperature data from the Halogen Occultation Experiment (HALOE) instrument on the Upper Atmosphere Research Satellite (UARS). Previous analyses of lidar temperature data found positive temperature anomalies of up to 12.9 K in the upper mesosphere that peaked in 1993 and were attributed to the Pinatubo eruption. Fitting the HALOE data according to a previously published method indicates a maximum warming of the mesosphere region of 4.1 ± 1.4 K and does not confirm significantly higher values reported for that lidar time series. An alternative fit is proposed that assumes a more rapid response of the mesosphere to the volcanic event and approximates the signature of the Pinatubo with an exponential decay function having an e-folding time of 6 months. It suggests a maximum warming of 5.4 ± 3.0 K, if the mesospheric perturbation is assumed to reach its peak 4 months after the eruption. We conclude that the HALOE time series probably captures the decay of a Pinatubo-induced mesospheric warming at the beginning of its measurement period.

Impact of a strong volcanic eruption on the summer middle atmosphere in UA-ICON simulations

“…These observations can only be qualitatively compared to our model results (in the following we will only discuss Ref1 and Vol1), because the experiments assume twice as much SO 2 emission as was released during the Pinatubo eruption. An almost instant response with maximum temperature anomalies measured in 1991 was reported for OH* rotational temperatures over Wuppertal at 51.3 • N (Kalicinsky et al, 2016;Offermann et al, 2010) and for satellite-based HALOE temperature measurements (Wallis et al, 2022). UA-ICON does not simulate a warming of the upper mesopause at 50°N, as was observed in OH* temperature measurements.…”