Record growth of stratospheric aerosols after the 2019 Raikoke eruption
The exact nature of the particles injected into the stratosphere after a volcanic eruption is of primary importance for understanding their impact on climate. Volcanic emissions are rich in sulfur dioxide (SO2), a gas which converts into sulfuric acid droplets in the stratosphere. Climate modellers generally consider only the role of sulfuric aerosols, or sulfates, for their capacity to modify the Earth’s radiative balance: by reflecting sunlight, these sulfates tend to cool the Earth’s surface. In the case of explosive eruptions, the influence of ash particles is commonly neglected, as they are considered to be deposited rapidly, within a few hours or days.
In June 2019, the major eruption of the Raikoke volcano (Kuril Islands) injected between 1.5 and 2.1 Tg of SO2 into the stratosphere, between 10 and 15 km of altitude, and perturbed the stratospheric aerosol layer for more than six months. While most of the volcanic plume dispersed into the Northern Hemisphere, a subset turned into a vortex and developed independently over two to three months. The observation of a vorticized plume is new for a volcanic eruption, although already documented for megafire plumes, and it raises the question of the nature of the particles it contains.
Characterising the size and composition of stratospheric particles at this level of detail cannot be achieved with a single observing system. It requires the synergistic exploitation of heterogeneous, distributed datasets: SO2 columns from satellite sounders, aerosol optical and microphysical properties from the global AERONET ground-based photometric network, and depolarization measurements from spaceborne lidar. The scientific challenge is therefore as much a data challenge — finding, co-locating and jointly analysing observations from different communities, instruments and archives, over several months and at hemispheric scale — as an atmospheric physics one.
Researchers from the Laboratoire d’Optique Atmosphérique (LOA, Université de Lille / CNRS) and the Institut de Physique du Globe de Paris (IPGP), working with engineers of the AERIS/ICARE national data and service centre for the atmosphere (Data Terra research infrastructure), addressed this challenge using the VOLCPLUME web platform of the Volcano Space Observatory (VSO). The platform enables a combined analysis of satellite observations and ground-based photometric measurements, to which a methodology developed for the exceptional Hunga eruption (Boichu et al., 2023) was applied.
Use-case contact
Paul Ruyneau de Saint-George — Université de Lille, Laboratoire d’Optique Atmosphérique (LOA)
Marie Boichu — CNRS, Université de Lille, Laboratoire d’Optique Atmosphérique (LOA)
Related project
FAIR-EASE
Partnership
- Laboratoire d’Optique Atmosphérique (LOA), Université de Lille / CNRS
- Institut de Physique du Globe de Paris (IPGP)
- AERIS/ICARE, national data and service centre for the atmosphere — Data Terra research infrastructure
- Global AERONET network (NASA / PHOTONS-AERIS) and Copernicus Sentinel-5P mission, as data providers
Thematic pillars
Contributions to EOSC Federation
This use case illustrates the added value of a federated, service-oriented environment for multi-source, cross-domain Earth science
A federating service
VOLCPLUME (VSO — Volcano Space Observatory), operated by AERIS/ICARE within the Data Terra infrastructure, brings together in a single interface satellite and ground-based observations of volcanic plumes that are otherwise distributed across different archives, communities and data formats. Users can visualise, co-locate and extract multi-parameter time series on the fly, without downloading and reprocessing large volumes of data locally.
Synergy between distributed datasets
The study combines SO2 columns from S5P/TROPOMI, aerosol optical depth and microphysical properties from the AERONET network, and lidar depolarization profiles from CALIPSO/CALIOP. The federation makes this synergy operational — identifying the AERONET stations overpassed by a given plume, and following it for six months at hemispheric scale.
Long-term value of archived missions
Part of the results rely on CALIPSO/CALIOP, a mission now decommissioned: curated, documented and interoperable archives maintained by the node are a prerequisite for this type of a posteriori analysis, and for revisiting past eruptions.
Cross-node, cross-discipline collaboration
The use case connects the atmosphere and solid Earth communities (LOA, IPGP, AERIS/ICARE), demonstrating the capacity of the federation to support research questions that fall between thematic domains, from volcanology to aerosol physics and climate modelling.
Reproducibility and reuse.
The methodology developed for the Hunga eruption (Boichu et al., 2023) was directly transferred to a new event through the same platform, illustrating how services — and not only datasets — can be reused across studies and by the wider community.