Preprints
https://doi.org/10.5194/acp-2020-982
https://doi.org/10.5194/acp-2020-982

  12 Oct 2020

12 Oct 2020

Review status: a revised version of this preprint was accepted for the journal ACP and is expected to appear here in due course.

Measurement Report: Lidar measurements of stratospheric aerosol following the Raikoke and Ulawun volcanic eruptions

Geraint Vaughan1, David Wareing2, and Hugo Ricketts1 Geraint Vaughan et al.
  • 1National Centre for Atmospheric Science, University of Manchester, UK
  • 2Aberystwyth University, UK

Abstract. On 22 June 2019 the Raikoke volcano in the Kuril islands erupted, sending a plume of ash and sulphur dioxide into the stratosphere. A Raman lidar system at Capel Dewi Atmospheric Observatory, UK (52.4° N, 4.1° W) has been used to measure the extent and optical depth of the stratospheric aerosol layer following the eruption. The elastic channel allowed measurements up to 25 km, but the Raman channel was only sensitive to the troposphere. Therefore, backscatter ratio profiles were derived by comparison with aerosol-free profiles derived from nearby radiosondes, corrected for aerosol extinction with a lidar ratio of 40–50 sr. Small amounts of aerosol were measured prior to the arrival of the volcanic cloud, probably from pyroconvection over Canada. Volcanic ash may have first arrived as a thin layer at 14 km late on 3 July, and was certainly detected from 13 July onwards, eventually extending up to 20.5 km. Aerosol optical depths reached around 0.05 by early August, decaying thereafter to around 0.01 by the end of 2019 and remaining around that level until May 2020. The location of peak backscatter varied considerably but was generally around 15 km. However, on one notable occasion on 25 August, a layer around 300 m thick with peak lidar backscatter ratio around 1.5 was observed as high as 21 km.

Geraint Vaughan et al.

 
Status: closed
Status: closed
AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment
Printer-friendly Version - Printer-friendly version Supplement - Supplement
 
Status: closed
Status: closed
AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment
Printer-friendly Version - Printer-friendly version Supplement - Supplement

Geraint Vaughan et al.

Geraint Vaughan et al.

Viewed

Total article views: 342 (including HTML, PDF, and XML)
HTML PDF XML Total BibTeX EndNote
256 82 4 342 2 3
  • HTML: 256
  • PDF: 82
  • XML: 4
  • Total: 342
  • BibTeX: 2
  • EndNote: 3
Views and downloads (calculated since 12 Oct 2020)
Cumulative views and downloads (calculated since 12 Oct 2020)

Viewed (geographical distribution)

Total article views: 422 (including HTML, PDF, and XML) Thereof 421 with geography defined and 1 with unknown origin.
Country # Views %
  • 1
1
 
 
 
 
Latest update: 08 Apr 2021
Download
Short summary
This paper documents the evolution of the cloud of volcanic aerosol introduced into the stratosphere by the eruption of Raikoke in June 2019. The measurements were made by a UV lidar (laser radar) operated at Capel Dewi, Wales, between June 2019 and May 2020. They show how the cloud of volcanic aerosol arrived at the site and how its optical depth decreased by a factor of five over the 11 months of measurements.
Altmetrics