The impact of volcanic eruptions, pyrocumulonimbus plumes, and the Arctic polar vortex intrusions on aerosol loading over Tomsk (Western Siberia, Russia) as observed by lidar from 2018 to 2022

ABSTRACT

Long-term ground-based lidar observations are important in estimating the contribution of different sources (mostly volcanic eruptions and wildfires) to aerosol loading of the atmosphere and in developing and improving various climate models. In this paper, we carefully analyse aerosol scattering ratio profiles and aerosol layers, observed with 532-nm lidar measurements at the Siberian Lidar Station in Tomsk (56.48°N, 85.05°E) over the period 2018–2022, and identify the layers’ potential sources. To compare aerosol loading over Tomsk for the last five years (2018–2022) with that for previous years, we also present and discuss time series of integrated aerosol backscatter coefficient (IABC) for three altitude ranges. The first range (15–30 km) reveals the pure stratospheric aerosol loading provided by volcanic eruptions, the second range (11–15 km) is responsible mainly for aftereffects of wildfire smoke plumes, and the third one (11–30 km) demonstrates aerosol contribution from both sources. In particular, we found for the period 2001–2022 that the annual average IABC reached its maximal values of 2.91 × 10⁻⁴ sr⁻¹ (15–30 km) and 8.21 × 10⁻⁴ sr⁻¹ (11–30 km) in 2022 due to the Hunga Tonga-Hunga Ha’apai volcanic eruption. The period 2020–2022 exhibited a significant increase in the relative aerosol content at altitudes of 11–15 km in the total aerosol loading at 11–30 km over Tomsk from 54.4% in 2020 to 64.8% in 2022, which indicates a shift of the main part of aerosol loading to altitudes of 11–15 km due to the increased wildfire activity in North America and north-eastern Asia. The Arctic polar vortex is also revealed to distort the real aerosol vertical distribution over Tomsk by replacing it with the aerosol distribution inside the vortex on measurement days when the vortex is over the lidar site.

KEYWORDS:

• Volcanic aerosol
• wildfire
• pyrocumulonimbus
• Arctic polar vortex
• lidar
• aerosol backscatter coefficient
• aerosol scattering ratio
• ERA5 reanalysis
• HYSPLIT model
• CALIPSO

Acknowledgements

We thank all scientists (especially Michael Fromm) who are actively involved in the search and identification of pyroCb events as well as in posting materials in blogs of the Cooperative Institute for Meteorological Satellite Studies and Worldwide PyroCb Information Exchange group, without which our analysis was not possible. We thank Colin Seftor for creating Figure 16 and kind permission to use it in our study. Vladislav Gerasimov also thanks Hande Erchel for her support during the writing of this paper.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

All the databases and models used along with figures based on them that support the findings of this study are openly available from the repositories described in Section 2.4. The time series of the IABC values (IABC 1986–2022.opj) obtained at the SLS as well as the information on volcanic eruptions (Table S1) and pyroCb events (Table S2) for the period 2018–2022 discussed in this study are presented in Supplemental material. Additional Figures S1–S10 showing the CALIPSO data are also given in Supplemental material. To open ‘IABC 1986–2022.opj’, the scientific graphing and data analysis software ‘Origin’ is required, the trial version or which can be downloaded at https://www.originlab.com/try.

Supplemental data

Supplemental data for this article can be accessed online at https://doi.org/10.1080/01431161.2024.2377833

Additional information

Funding

This work was supported by the Ministry of Science and Higher Education of the Russian Federation (V.E. Zuev Institute of Atmospheric Optics, Siberian Branch, Russian Academy of Sciences, and Institute of Monitoring of Climatic and Ecological Systems, Siberian Branch, Russian Academy of Sciences [project # 121031300156-5]); and the Russian Science Foundation [project # 23-17-00273]. The analysis of the impact of the Arctic polar vortex intrusions on aerosol loading over Tomsk was carried out within the framework of the project [# 23-17-00273, https://rscf.ru/en/project/23-17-00273/].