Response of Trace Gases to the Disrupted 2015–2016 Quasi-Biennial Oscillation

During the late-2015 through 2016 period, the wind pattern in the tropical stratosphere, known as the quasi-biennial oscillation (QBO), experienced a major disruption that was unprecedented in 1953-present observational record. In this study we examine the response of trace gases to this QBO disruption using ozone (O₃), hydrochloric acid (HCl), water (H₂O) and temperature from the Aura Microwave Limb Sounder (MLS) and total ozone measurements from the Solar Backscatter Ultraviolet (SBUV) Merged Ozone Data Set (MOD). We show there were positive anomalies in stratospheric equatorial O₃ and HCl over ∼ 50-30 hPa in May-September of 2016 and a substantial decrease in O₃ in the subtropics of both hemispheres. As a consequence of the disruption, extratropical total O₃ values during the spring-summer 2016 were at or near record lows over the more than 40 years of the total ozone data, resulting in an increase of surface UV index during northern summer. Furthermore, cold temperature anomalies near the tropical tropopause result in a global decrease in stratospheric water vapor during the fall 2016. As impact of the QBO-induced circulation on stratospheric trace gases can persist for a long period, we continue to monitor and show the evolution and behavior of the trace gases during the winter and spring 2017.