Response of stratospheric water vapor and ozone to the unusual timing of El Niño and the QBO disruption in 2015–2016

• Published in: Atmospheric chemistry and physics Vol. 18; no. 17; pp. 13055 - 13073
• Main Authors: Diallo, Mohamadou, Riese, Martin, Birner, Thomas, Konopka, Paul, Müller, Rolf, Hegglin, Michaela I., Santee, Michelle L., Baldwin, Mark, Legras, Bernard, Ploeger, Felix
• Format: Journal Article
• Language: English
• Published: Katlenburg-Lindau Copernicus GmbH 11-09-2018; European Geosciences Union; Copernicus Publications
• Subjects: Alignment; Climate; Climate change; Disruption; El Nino; El Nino phenomena; El Nino-Southern Oscillation event; Future climates; Gases; Lower stratosphere; Ocean, Atmosphere; Ozone; Perturbation; Quasi-biennial oscillation; Satellite observation; Satellites; Sciences of the Universe; Southern Oscillation; Stratosphere; Stratospheric circulation; Trace gases; Tropical climate; Water vapor; Water vapour; Pacific Ocean
• ISSN: 1680-7324; 1680-7316; 1680-7324
• DOI: 10.5194/acp-18-13055-2018

The stratospheric circulation determines the transport and lifetime of key
trace gases in a changing climate, including water vapor and ozone, which
radiatively impact surface climate.
The unusually warm El Niño–Southern Oscillation (ENSO) event aligned with a
disrupted Quasi-Biennial Oscillation (QBO) caused an unprecedented perturbation
to this circulation in 2015–2016.
Here, we quantify the impact of the alignment of these two phenomena in 2015–2016
on lower stratospheric water vapor and ozone from satellite observations. We show
that the warm ENSO event substantially increased water vapor and decreased ozone
in the tropical lower stratosphere.
The QBO disruption significantly decreased global lower stratospheric water vapor
and tropical ozone from early spring to late autumn.
Thus, this QBO disruption reversed the lower stratosphere moistening triggered
by the alignment of the warm ENSO event with westerly QBO in early boreal winter.
Our results suggest that the interplay of ENSO events and QBO phases will be
crucial for the distributions of radiatively active trace gases
in a changing future climate, when increasing El Niño-like conditions and
a decreasing lower stratospheric QBO amplitude are expected.