Preprints
https://doi.org/10.5194/acp-2021-479
https://doi.org/10.5194/acp-2021-479

  22 Jun 2021

22 Jun 2021

Review status: this preprint is currently under review for the journal ACP.

The Effects of the COVID-19 Lockdowns on the Composition of the Troposphere as Seen by IAGOS

Hannah Clark1, Yasmine Bennouna2,4, Maria Tsivlidou2, Pawel Wolff2, Bastien Sauvage2, Brice Barret2, Eric Le Flochmoën2, Romain Blot2, Damien Boulanger5, Jean-Marc Cousin2, Philippe Nédélec2, Andreas Petzold3, and Valérie Thouret2 Hannah Clark et al.
  • 1IAGOS-AISBL, 98 Rue du Trône, Brussels, Belgium
  • 2Laboratoire d’Aérologie (LAERO), CNRS and Université de Toulouse III, Paul Sabatier, Toulouse, France
  • 3Forschungszentrum Julich, Institute of Energy and Climate Research 8: Troposphere, Jülich, Germany
  • 4Royal Netherlands Meteorological Institute (KNMI), De Bilt, the Netherlands
  • 5Observatoire Midi-Pyrénées (OMP-SEDOO), CNRS and Université de Toulouse III, Paul Sabatier, Toulouse, France

Abstract. The European Research Infrastructure IAGOS (In-service Aircraft for a Global Observing System) equips commercial aircraft with a system for measuring atmospheric composition. A range of essential climate variables and air quality parameters are measured throughout the flight, from take-off to landing, giving high resolution information in the vertical in the vicinity of international airports, and in the upper-troposphere/lower-stratosphere during the cruise phase of the flight. Six airlines are currently involved in the programme, achieving a quasi-global coverage under normal circumstances. During the COVID-19 crisis, many airlines were forced to ground their fleets due to a fall in passenger numbers and imposed travel restrictions. Deutsche Lufthansa, a partner in IAGOS since 1994 was able to operate a IAGOS-equipped aircraft during the COVID-19 lockdown, providing regular measurements of ozone and carbon monoxide at Frankfurt airport. The data form a snapshot of an unprecedented time in the 27 year time-series. In May 2020, we see a 39 % increase in ozone near the surface with respect to the 26 year climatology, a magnitude similar to that of the 2003 heatwave. The anomaly in May is driven by an increase in ozone at nighttime which might be linked to the reduction of NO during the COVID-19 lockdowns. The anomaly diminishes with altitude becoming a slightly negative anomaly in the free troposphere. The ozone precursor carbon monoxide shows an 11 % reduction in MAM near the surface. There is only a small reduction of CO in the free troposphere due to the impact of long-range transport on the CO from emissions in regions outside Europe. This is confirmed by IASI-SOFRID CO retrievals which display a clear drop of CO at 800 hPa over Europe in March but otherwise show little change to the abundance of CO in the free troposphere.

Hannah Clark et al.

Status: open (until 03 Aug 2021)

Comment types: AC – author | RC – referee | CC – community | EC – editor | CEC – chief editor | : Report abuse
  • RC1: 'Reviewer Comments on acp-2021-479', Anonymous Referee #1, 18 Jul 2021 reply
  • RC2: 'Comment on acp-2021-479', Anonymous Referee #2, 21 Jul 2021 reply

Hannah Clark et al.

Hannah Clark et al.

Viewed

Total article views: 335 (including HTML, PDF, and XML)
HTML PDF XML Total BibTeX EndNote
244 86 5 335 4 3
  • HTML: 244
  • PDF: 86
  • XML: 5
  • Total: 335
  • BibTeX: 4
  • EndNote: 3
Views and downloads (calculated since 22 Jun 2021)
Cumulative views and downloads (calculated since 22 Jun 2021)

Viewed (geographical distribution)

Total article views: 336 (including HTML, PDF, and XML) Thereof 336 with geography defined and 0 with unknown origin.
Country # Views %
  • 1
1
 
 
 
 
Latest update: 28 Jul 2021
Download
Short summary
We examined 27 years of IAGOS (In-service Aircraft for a Global Observing System) measurements at Frankfurt to see if there were unusual or extreme features during the spring of 2020 when there were lockdowns across Europe and when pollution was reported to have fallen. Ozone increased at the surface which might be linked to the reduction of pollution from lockdown. The amount of CO decreased but the impact of the lockdowns in Europe was off-set by pollution from elsewhere.
Altmetrics