Aircraft observations since the 1990s reveal increases of tropospheric ozone at multiple locations across the Northern Hemisphere.
Audrey Gaudel, Owen R Cooper, Kai-Lan Chang, Ilann Bourgeois, Jerry R Ziemke, Sarah A Strode, Luke D Oman, Pasquale Sellitto, Philippe Nédélec, Romain Blot, Valérie Thouret, Claire Granier
Author Information
Audrey Gaudel: CIRES, University of Colorado/NOAA Chemical Sciences Laboratory, Boulder, CO, USA. audrey.gaudel@noaa.gov. ORCID
Owen R Cooper: CIRES, University of Colorado/NOAA Chemical Sciences Laboratory, Boulder, CO, USA. ORCID
Kai-Lan Chang: CIRES, University of Colorado/NOAA Chemical Sciences Laboratory, Boulder, CO, USA. ORCID
Ilann Bourgeois: CIRES, University of Colorado/NOAA Chemical Sciences Laboratory, Boulder, CO, USA. ORCID
Jerry R Ziemke: NASA Goddard Space Flight Center, Greenbelt, MD, USA.
Sarah A Strode: NASA Goddard Space Flight Center, Greenbelt, MD, USA. ORCID
Luke D Oman: NASA Goddard Space Flight Center, Greenbelt, MD, USA. ORCID
Pasquale Sellitto: Laboratoire Interuniversitaire des Systèmes Atmosphériques, UMR CNRS 7583, Université Paris-Est Créteil, Université de Paris, Institut Pierre Simon Laplace, Créteil, France. ORCID
Philippe Nédélec: Laboratoire d'Aérologie, Université de Toulouse, CNRS, UPS, France. ORCID
Romain Blot: Laboratoire d'Aérologie, Université de Toulouse, CNRS, UPS, France. ORCID
Valérie Thouret: Laboratoire d'Aérologie, Université de Toulouse, CNRS, UPS, France. ORCID
Claire Granier: CIRES, University of Colorado/NOAA Chemical Sciences Laboratory, Boulder, CO, USA. ORCID
Tropospheric ozone is an important greenhouse gas, is detrimental to human health and crop and ecosystem productivity, and controls the oxidizing capacity of the troposphere. Because of its high spatial and temporal variability and limited observations, quantifying net tropospheric ozone changes across the Northern Hemisphere on time scales of two decades had not been possible. Here, we show, using newly available observations from an extensive commercial aircraft monitoring network, that tropospheric ozone has increased above 11 regions of the Northern Hemisphere since the mid-1990s, consistent with the OMI/MLS satellite product. The net result of shifting anthropogenic ozone precursor emissions has led to an increase of ozone and its radiative forcing above all 11 study regions of the Northern Hemisphere, despite NO emission reductions at midlatitudes.
