11 Aug 2022
 | 11 Aug 2022
Status: a revised version of this preprint is currently under review for the journal AMT.

SAGE III/ISS aerosol/cloud categorization and its impact on GloSSAC

Mahesh Kovilakam, Larry Thomason, and Travis Knepp

Abstract. The Stratospheric Aerosol and Gas Experiment on the International Space Station (SAGE III/ISS) began its mission in June 2017. SAGE III/ISS is an updated version of the SAGE III on Meteor (SAGE III/M3M) instrument that makes observations of stratospheric aerosol extinction coefficient at wavelengths that range from 385 to 1550 nm with a near global coverage between 60° S and 60° N. While SAGE III/ISS makes reliable and robust solar occultation measurements in stratosphere, similar to its predecessors, interpreting aerosol extinction measurements in the vicinity of tropopause and in the troposphere have been a challenge for all SAGE instruments. Herein, we discuss some of the challenges associated with discriminating between aerosols and clouds within the extinction measurements and describe the methods implemented to categorize clouds and aerosols using available SAGE III/ISS aerosol measurements. This cloud/aerosol categorization method is based on the results of Thomason and Vernier (2013) with some modifications that now incorporate the influence of recent volcanic/PyroCb events and a new method of locating aerosol centroid based on k-medoid clustering. We use version 5.2 of SAGE III/ISS extinction coefficients for the analysis. The current algorithm now classifies standard (background) and non-standard (enhanced) aerosols in the stratosphere and identify enhanced aerosols and aerosol/cloud mixture in the tropopause region. SAGE data is an important dataset in the GloSSAC data base and therefore, the impact of cloud-filtered aerosol extinction coefficient measurements on the latest version of GloSSAC (version 2.2) is also discussed.

Mahesh Kovilakam et al.

Status: final response (author comments only)

Comment types: AC – author | RC – referee | CC – community | EC – editor | CEC – chief editor | : Report abuse
  • RC1: 'Comment on amt-2022-222', Anonymous Referee #1, 25 Oct 2022
  • RC2: 'Comment on amt-2022-222', Anonymous Referee #2, 11 Nov 2022
  • EC1: 'Comment on amt-2022-222', Omar Torres, 24 Mar 2023

Mahesh Kovilakam et al.

Mahesh Kovilakam et al.


Total article views: 489 (including HTML, PDF, and XML)
HTML PDF XML Total BibTeX EndNote
366 107 16 489 11 7
  • HTML: 366
  • PDF: 107
  • XML: 16
  • Total: 489
  • BibTeX: 11
  • EndNote: 7
Views and downloads (calculated since 11 Aug 2022)
Cumulative views and downloads (calculated since 11 Aug 2022)

Viewed (geographical distribution)

Total article views: 495 (including HTML, PDF, and XML) Thereof 495 with geography defined and 0 with unknown origin.
Country # Views %
  • 1
Latest update: 24 Mar 2023
Short summary
The manuscript describes SAGE III/ISS aerosol/cloud categorization and its implications on Global Space-based Stratospheric Aerosol Climatology (GloSSAC). The presence of data from SAGE type of multi-wavelength measurements is important in GloSSAC. The new aerosol/cloud categorization method described in this manuscript will help retain more measurements, particularly in the lower stratosphere during and following volcanic event and other processes.