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.
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 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