EGUsphere EGUsphere EGUsphere EGUsphere Copernicus Publications Göttingen, Germany 10.5194/egusphere-2026-3280 A new Profiling Optical Particle Counter to study stratospheric aerosols Vernier Jean-Paul 1 2 3 Dumelie Nicolas 3 Pandit Amit Kumar https://orcid.org/0000-0002-1957-5934 1 Berthet Gwenael https://orcid.org/0000-0003-3169-1636 4 Joly Lilian 3 de Souza Giovanni https://orcid.org/0000-0003-3426-5528 5 Landulfo Eduardo https://orcid.org/0000-0002-9691-5306 5 Quintao Demilson 6 Biazon Bruno 6 Kiran Ravi https://orcid.org/0000-0001-8773-7336 7 Ratnam Vankat https://orcid.org/0000-0002-3882-2523 7 Flaten James 8 Das Rubel https://orcid.org/0009-0009-8187-2209 1 Paraiseau David 9 Wienhold Frank 10 Li Yaowei https://orcid.org/0000-0003-0725-6108 11 National Institute of Aerospace, USA NASA Langley Research Center, USA CIEL, Université de Reims Champagne Ardenne, Reims, France Laboratoire de Physique Chimie de l’Environnement et du Climat, Orleans, France Instituto de Pesquisas Energéticas e Nucleares Brazil, Brazil IPMet – Centro de Meteorologia de Bauru – FC/Unesp, Bauru, Brazil National Atmospheric Research Laboratory, India University of Minnesota, Minneapolis, USA Particle Plus, Inc, Stoughton, USA ETH, Zurich, Switzerland Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, USA 23 06 2026 2026 1 38 Copyright: © 2026 Jean-Paul Vernier et al. 2026 This work is licensed under the Creative Commons Attribution 4.0 International License. To view a copy of this licence, visit https://creativecommons.org/licenses/by/4.0/ This article is available from https://egusphere.copernicus.org/preprints/2026/egusphere-2026-3280/ The full text article is available as a PDF file from https://egusphere.copernicus.org/preprints/2026/egusphere-2026-3280/egusphere-2026-3280.pdf

Stratospheric aerosols play key roles in the radiative and chemical balance of the atmosphere, especially after volcanic and wildfire activities. The sources of stratospheric aerosols have become more complex over the last decade through the influence of Asian pollution, rocket and satellite debris, which could be further enhanced with the potential use of stratospheric aerosol injection under solar radiation management. Knowing stratospheric aerosol size distribution is a fundamental step toward calculating and evaluating their radiative, chemical and climate impacts and validating and/or constraining satellite observations.</p> <p>We describe here the adaptation of the new lightweight, medium-cost Profiling Optical Particle Counters (POPC) for weather balloon applications. Over the past 8 years, the POPC design and capabilities evolved from a handheld version with 6 channels (POPC-06) to a compact 500g-version with 30 channels measuring aerosol optical diameters between 0.3 to 10 &micro;m. POPC-30 aerosol concentration for d &gt;0.3 &micro;m.&nbsp; is shown to be within 20% of the Portable Optical Particle Spectrometer (POPS), correlates near 0.97 with the COmpact Backscatter AerosoL Detector (COBALD) and lies within 50% of the extinction coefficients retrieved from highly accurate solar occultation measurements from the Stratospheric Aerosol and Gas Experiment (SAGE III/ISS). With 87 flights since 2018, POPC demonstrated its capabilities to detect volcanic plumes after the 2019 Raikoke, 2019 Ambae, 2021 La Soufriere, 2022 Hunga and 2024 Ruang eruptions and was deployed rapidly to intersect pyroCb smoke plumes in the Northern Hemisphere. The instrument is currently launched by several universities and research institutes in Brazil, India, France and the US as a part of the <strong>Bal</strong>loon <strong>Ne</strong>twork for stratospheric aerosol <strong>O</strong>bservations (BalNeO) complementing other measurement networks. POPC data set is publicly available to the research community for various applications ranging from boundary layer aerosols to free tropospheric and stratospheric aerosol microphysics.

 NASA Headquarters NNH24ZDA001N-UACO