scholarly journals 30-year lidar observations of the stratospheric aerosol layer state over Tomsk (Western Siberia, Russia)

2016 ◽  
Author(s):  
Vladimir V. Zuev ◽  
Vladimir D. Burlakov ◽  
Aleksei V. Nevzorov ◽  
Vladimir L. Pravdin ◽  
Ekaterina S. Savelieva ◽  
...  
Keyword(s):  
Forest Fires ◽  
Western Siberia ◽  
Volcanic Eruptions ◽  
Stratospheric Aerosol ◽  
Aerosol Layer ◽  
Smoke Plumes ◽  
Soufriere Hills ◽  
The Usa ◽  
Global Volcanism ◽  
Langley Research Center

Abstract. There are only four lidar stations in the world, which have almost continuously performed observations of the stratospheric aerosol layer (SAL) state for over the last 30 years. The longest time series of the SAL lidar measurements have been accumulated at the Mauna Loa Observatory (Hawaii) since 1973, the NASA Langley Research Center (Hampton, Virginia) since 1974, and Garmisch-Partenkirchen (Germany) since 1976. The fourth lidar station we present started to perform routine observations of the SAL parameters in Tomsk (56.48° N, 85.05° E, Western Siberia, Russia) in 1986. In this paper, we mainly focus on and discuss the stratospheric background period from 2000 to 2005 and the causes of the SAL perturbations over Tomsk in the 2006–2015 period. During the last decade, volcanic aerosol plumes from tropical Mt. Manam, Soufriere Hills, Rabaul, Merapi, Nabro, and Kelut, and extratropical (northern) Mt. Okmok, Kasatochi, Redoubt, Sarychev Peak, Eyjafjallajökull, and Grimsvötn were detected in the stratosphere over Tomsk. When it was possible, we used the NOAA HYSPLIT trajectory model to assign aerosol layers observed over Tomsk to the corresponding volcanic eruptions. The trajectory analysis highlighted some surprising results. For example, in cases of the Okmok, Kasatochi, and Eyjafjallajökull eruptions, the HYSPLIT air-mass backward trajectories, started from altitudes of aerosol layers detected over Tomsk with a lidar, passed over these volcanoes on their eruption days at altitudes higher than the maximum plume altitudes given by the Smithsonian Institution Global Volcanism Program. An explanation of these facts is suggested. The role of both tropical and northern volcanoes eruptions in volcanogenic aerosol loading of the mid-latitude stratosphere is also discussed. In addition to volcanoes, we considered other possible causes of the SAL perturbations over Tomsk, i.e. the polar stratospheric cloud (PSC) events and smoke plumes from strong forest fires. At least two PSC events were detected in 1995 and 2007. We also make an assumption that both the Kelut volcano plume (Indonesia, February 2014) and smoke plumes from massive forest fires occurred in Canada (137 fires in the Northwest Territories, July 2014) and the USA (the Happy Camp Complex fire in California, August–October 2014), with equal probability, could be the cause of the SAL perturbations over Tomsk during the first quarter of 2015.

scholarly journals 30-year lidar observations of the stratospheric aerosol layer state over Tomsk (Western Siberia, Russia)

2017 ◽  
Vol 17 (4) ◽  
pp. 3067-3081 ◽  
Author(s):  
Vladimir V. Zuev ◽  
Vladimir D. Burlakov ◽  
Aleksei V. Nevzorov ◽  
Vladimir L. Pravdin ◽  
Ekaterina S. Savelieva ◽  
...  
Keyword(s):  
Forest Fires ◽  
Western Siberia ◽  
Volcanic Eruptions ◽  
Stratospheric Aerosol ◽  
Aerosol Layer ◽  
Background Period ◽  
Lidar Measurements ◽  
Soufriere Hills ◽  
Global Volcanism ◽  
Langley Research Center

Abstract. There are only four lidar stations in the world which have almost continuously performed observations of the stratospheric aerosol layer (SAL) state over the last 30 years. The longest time series of the SAL lidar measurements have been accumulated at the Mauna Loa Observatory (Hawaii) since 1973, the NASA Langley Research Center (Hampton, Virginia) since 1974, and Garmisch-Partenkirchen (Germany) since 1976. The fourth lidar station we present started to perform routine observations of the SAL parameters in Tomsk (56.48° N, 85.05° E, Western Siberia, Russia) in 1986. In this paper, we mainly focus on and discuss the stratospheric background period from 2000 to 2005 and the causes of the SAL perturbations over Tomsk in the 2006–2015 period. During the last decade, volcanic aerosol plumes from tropical Mt. Manam, Soufrière Hills, Rabaul, Merapi, Nabro, and Kelut and extratropical (northern) Mt. Okmok, Kasatochi, Redoubt, Sarychev Peak, Eyjafjallajökull, and Grímsvötn were detected in the stratosphere over Tomsk. When it was possible, we used the NOAA HYSPLIT trajectory model to assign aerosol layers observed over Tomsk to the corresponding volcanic eruptions. The trajectory analysis highlighted some surprising results. For example, in the cases of the Okmok, Kasatochi, and Eyjafjallajökull eruptions, the HYSPLIT air mass backward trajectories, started from altitudes of aerosol layers detected over Tomsk with a lidar, passed over these volcanoes on their eruption days at altitudes higher than the maximum plume altitudes given by the Smithsonian Institution Global Volcanism Program. An explanation of these facts is suggested. The role of both tropical and northern volcanic eruptions in volcanogenic aerosol loading of the midlatitude stratosphere is also discussed. In addition to volcanoes, we considered other possible causes of the SAL perturbations over Tomsk, i.e., the polar stratospheric cloud (PSC) events and smoke plumes from strong forest fires. At least two PSC events were detected in 1995 and 2007. We also make an assumption that the Kelut volcanic eruption (Indonesia, February 2014) could be the cause of the SAL perturbations over Tomsk during the first quarter of 2015.

scholarly journals Lidar observations of pyrocumulonimbus smoke plumes in the UTLS over Tomsk (Western Siberia, Russia) from 2000 to 2017

2019 ◽  
Vol 19 (5) ◽  
pp. 3341-3356 ◽  
Author(s):  
Vladimir V. Zuev ◽  
Vladislav V. Gerasimov ◽  
Aleksei V. Nevzorov ◽  
Ekaterina S. Savelieva
Keyword(s):  
North America ◽  
Western Siberia ◽  
Far East ◽  
Volcanic Eruptions ◽  
Combustion Products ◽  
Backscatter Coefficient ◽  
Average Value ◽  
Aerosol Loading ◽  
Smoke Plumes ◽  
The Usa

Abstract. Large volcanic eruptions with the volcanic explosivity index (VEI) ≥ 3 are widely known to be the strongest source of long-lived aerosol in the upper troposphere and lower stratosphere (UTLS). However, the latest studies have revealed that massive forest (bush) fires represent another strong source of short-term (but intense) aerosol perturbations in the UTLS if combustion products from the fires reach these altitudes via convective ascent within pyrocumulonimbus clouds (pyroCbs). PyroCbs, generated by boreal wildfires in North America and northeastern Asia and injecting smoke plumes into the UTLS, have been intensively studied using both ground- and space-based instruments since the beginning of the 21st century. In this paper, we focus on aerosol layers observed in the UTLS over Tomsk (56.48∘ N, 85.05∘ E, Western Siberia, Russia) that could be smoke plumes from such pyroCb events occurring in the 2000–2017 period. Using the HYSPLIT trajectory analysis, we have reliably assigned nine aerosol layers to 8 out of more than 100 documented pyroCb events, the aftereffects of which could potentially be detected in the UTLS over Tomsk. All the eight pyroCb events occurred in the USA and Canada: one event per year occurred in 2000, 2002, 2003, 2013, 2015, and 2016, whereas two events occurred in 2017. No plumes from pyroCbs originating in the boreal zone of Siberia and the Far East (to the east of Tomsk) were observed in the UTLS over Tomsk between 2000 and 2017. We conclude that the time durations for pyroCb plumes to be detected in the UTLS using ground-based lidars are less than about a month, i.e., plumes from pyroCbs generated by wildfires to the east of Tomsk can significantly diffuse before reaching the Tomsk lidar station by the westerly zonal transport of air masses. A comparative analysis of the contributions from pyroCb events and volcanic eruptions with VEI ≥ 3 to aerosol loading of the UTLS over Tomsk showed the following. Plumes from two or more pyroCbs that have occurred in North America in a single year are able to markedly increase the aerosol loading compared to the previous year. The annual average value of the integrated aerosol backscatter coefficient Bπ,532a increased by 14.8 % in 2017 compared to that in 2016 due to multiple pyroCbs occurring in British Columbia (Canada) in August 2017. The aftereffects of pyroCb events are comparable to those of volcanic eruptions with VEI ≤ 3, but even multiple pyroCbs can hardly compete with volcanic eruptions with VEI = 4.

scholarly journals Lower-stratospheric aerosol measurements in eastward shedding vortices over Japan from the Asian summer monsoon anticyclone during the summer of 2018

2020 ◽  
Author(s):  
Masatomo Fujiwara ◽  
Tetsu Sakai ◽  
Koichi Shiraishi ◽  
Yoichi Inai ◽  
Sergey Khaykin ◽  
...  
Keyword(s):  
Summer Monsoon ◽  
Forest Fires ◽  
Lower Stratosphere ◽  
Asian Summer Monsoon ◽  
Volcanic Eruptions ◽  
Stratospheric Aerosol ◽  
Aerosol Layer ◽  
Upper Troposphere ◽  
Asian Summer ◽  
The Japanese Archipelago

Abstract. Eastward airmass transport from the Asian summer monsoon (ASM) anticyclone in the upper troposphere and lower stratosphere (UTLS) often involves eastward shedding vortices, which can cover most of the Japanese archipelago. We investigated the aerosol characteristics of these vortices by analysing data from two lidar systems in Japan, at Tsukuba (36.1° N, 140.1° E) and Fukuoka (33.55° N, 130.36° E), during the summer of 2018. We observed several events with enhanced particle signals at Tsukuba at 15.5–18 km altitude (at or above the local tropopause) during August–September 2018, with a backscattering ratio of ~1.10 and particle depolarization of ~5 % (i.e., not spherical, but more spherical than ice crystals). These particle characteristics may be consistent with those of solid aerosol particles, such as ammonium nitrate. Each event had a timescale of a few days. During the same study period, we also observed similar enhanced particle signals in the lower stratosphere at Fukuoka. The upper troposphere is often covered by cirrus clouds at both lidar sites. Backward trajectory calculations for these sites for days with enhanced particle signals in the lower stratosphere and days without indicate that the former airmasses originated within the ASM anticyclone, and the latter more from edge regions. Reanalysis carbon-monoxide and satellite water-vapour data indicate that eastward shedding vortices were involved in the observed aerosol enhancements. Satellite aerosol data confirm that the period and latitudinal region were free from the direct influence of documented volcanic eruptions and high latitude forest fires. Our results indicate that the Asian Tropopause Aerosol Layer (ATAL) over the ASM region extends east towards Japan in association with the eastward shedding vortices, and that lidar systems in Japan can detect at least the lower stratospheric portion of the ATAL during periods when the lower stratosphere is undisturbed by volcanic eruptions and forest fires. The upper tropospheric portion of the ATAL is either depleted by tropospheric processes (convection and wet scavenging) during eastward transport or is obscured by much stronger cirrus cloud signals.

scholarly journals Lower-stratospheric aerosol measurements in eastward-shedding vortices over Japan from the Asian summer monsoon anticyclone during the summer of 2018

2021 ◽  
Vol 21 (4) ◽  
pp. 3073-3090
Author(s):  
Masatomo Fujiwara ◽  
Tetsu Sakai ◽  
Tomohiro Nagai ◽  
Koichi Shiraishi ◽  
Yoichi Inai ◽  
...  
Keyword(s):  
Summer Monsoon ◽  
Forest Fires ◽  
Lower Stratosphere ◽  
Asian Summer Monsoon ◽  
Volcanic Eruptions ◽  
Stratospheric Aerosol ◽  
Aerosol Layer ◽  
Upper Troposphere ◽  
Asian Summer ◽  
The Japanese Archipelago

Abstract. Eastward air-mass transport from the Asian summer monsoon (ASM) anticyclone in the upper troposphere and lower stratosphere (UTLS) often involves eastward-shedding vortices, which can cover most of the Japanese archipelago. We investigated the aerosol characteristics of these vortices by analysing data from two lidar systems in Japan, at Tsukuba (36.1∘ N, 140.1∘ E) and Fukuoka (33.55∘ N, 130.36∘ E), during the summer of 2018. We observed several events with enhanced particle signals at Tsukuba at 15.5–18 km of altitude (at or above the local tropopause) during August–September 2018, with a backscattering ratio of ∼ 1.10 and particle depolarization of ∼ 5 % (i.e. not spherical, but more spherical than ice crystals). These particle characteristics may be consistent with those of solid aerosol particles, such as ammonium nitrate. Each event had a timescale of a few days. During the same study period, we also observed similar enhanced particle signals in the lower stratosphere at Fukuoka. The upper troposphere is often covered by cirrus clouds at both lidar sites. Backward trajectory calculations for these sites for days with enhanced particle signals in the lower stratosphere and days without indicate that the former air masses originated within the ASM anticyclone and the latter more from edge regions. Reanalysis carbon monoxide and satellite water vapour data indicate that eastward-shedding vortices were involved in the observed aerosol enhancements. Satellite aerosol data confirm that the period and latitudinal region were free from the direct influence of documented volcanic eruptions and high-latitude forest fires. Our results indicate that the Asian tropopause aerosol layer (ATAL) over the ASM region extends east towards Japan in association with the eastward-shedding vortices and that lidar systems in Japan can detect at least the lower-stratospheric portion of the ATAL during periods when the lower stratosphere is undisturbed by volcanic eruptions and forest fires. The upper-tropospheric portion of the ATAL is either depleted by tropospheric processes (convection and wet scavenging) during eastward transport or is obscured by much stronger cirrus cloud signals.

scholarly journals Lidar observations of pyrocumulonimbus smoke plumes in the UTLS over Tomsk (Western Siberia, Russia) from 2000 to 2017

2018 ◽  
Author(s):  
Vladimir V. Zuev ◽  
Vladislav V. Gerasimov ◽  
Aleksei V. Nevzorov ◽  
Ekaterina S. Savelieva
Keyword(s):  
Western Siberia ◽  
Far East ◽  
Volcanic Eruptions ◽  
Combustion Products ◽  
Air Masses ◽  
North East ◽  
Smoke Plumes ◽  
Strong Source ◽  
The Usa ◽  
Aerosol Plume

Abstract. Large volcanic eruptions with the volcanic explosivity index (VEI) ≥ 3 are widely known to be the strongest source of long-lived aerosol in the upper troposphere and lower stratosphere (UTLS). However, the latest studies have revealed that massive forest (bush) fires represent another strong source of short-term (but intense) aerosol perturbations in the UTLS if combustion products from the fires reach these altitudes via convective ascent within pyrocumulonimbus clouds (pyroCbs). PyroCbs, generated by boreal wildfires in North America and North-East Asia and injecting smoke plumes into the UTLS, have been intensively studied using both ground- and space-based instruments since the beginning of the 21 century. In this paper, we focus on aerosol layers observed in the UTLS over Tomsk (56.48° N, 85.05° E, Western Siberia, Russia) that could be smoke plumes from such pyroCb events occurred in the 2000–2017 period. Using the HYSPLIT trajectory analysis, we have reliably assigned ten aerosol layers to nine out of more than 100 documented pyroCb events, the aftereffects of which could potentially be detected in the UTLS over Tomsk. All of the nine pyroCb events occurred in the USA and Canada: one event per year was in 2000, 2002, 2003, 2015, and 2016, whereas two events per year were in 2013 and 2017. No plumes from pyroCbs originating in the boreal zone of Siberia and the Far East (to the east of Tomsk) were observed in the UTLS over Tomsk between 2000 and 2017. We conclude that the lifetimes of pyroCb plumes to be detected in the UTLS using ground-based lidars are less than about a month, i.e. plumes from pyroCbs generated by wildfires to the east of Tomsk can significantly diffuse before reaching the Tomsk lidar station by the westerly zonal transport of air masses. A comparative analysis of the contributions from pyroCb events and volcanic eruptions with VEI ≥ 3 to aerosol loading of the UTLS over Tomsk has also been made. Finally, an aerosol plume from the Aleutian volcano Bogoslof erupted with VEI = 3 on 28 May 2017 was detected at altitudes between 10.8 and 13.5 km over Tomsk on 16 June 2017.

scholarly journals Evaluation of OMPS/LP Stratospheric Aerosol Extinction Product Using SAGE III/ISS Observations

2019 ◽  
Author(s):  
Zhong Chen ◽  
Pawan K. Bhartia ◽  
Omar Torres ◽  
Glen Jaross ◽  
Robert Loughman ◽  
...  
Keyword(s):  
Size Distribution ◽  
Forest Fires ◽  
Correlation Coefficients ◽  
Volcanic Eruptions ◽  
Stratospheric Aerosol ◽  
Aerosol Size Distribution ◽  
Retrieval Algorithm ◽  
Aerosol Layer ◽  
Aerosol Extinction ◽  
Extinction Time

Abstract. The Ozone Mapping and Profiler Suite Limb Profiler (OMPS/LP) has been flying on the Suomi NPP satellite since October 2011. It is designed to produce ozone and aerosol vertical profiles at 1.6 km vertical resolution over the entire sunlit globe. The Version 1.5 (V1.5) aerosol extinction retrieval algorithm provides aerosol extinction profiles using observed radiances at 675 nm. The algorithm assumes Mie theory and a gamma function aerosol size distribution for the stratospheric aerosol that is derived from Community Aerosol and Radiation Model for Atmospheres (CARMA) calculated results and observations in April 2012. In this paper, we compare V1.5 LP aerosol profiles with SAGE III/ISS solar occultation observations for the period June 2017 – May 2019, when both measurements were available. Overall, LP extinction profiles agree with SAGE data to within ±25 % for the main aerosol layer between 19 and 27 km, even during periods perturbed by volcanic eruptions or intense forest fires. The slope parameter of linear fitting of LP extinctions with respect to SAGE measurements are close to 1.0, with Pearson's correlation coefficients of r ≥ 0.95, indicating that the LP aerosol data are reliable in that altitude range. Comparisons of extinction time series show a high degree of correlation between LP and SAGE, indicating that the LP retrieved extinction variability in time is robust. On the other hand, we find that LP retrieved extinction is systematically higher than SAGE observations at altitudes above 28 km and systematically lower below 19 km in the tropics. This is likely due in part to the fact that the actual aerosol size distribution is altitude dependent, while the assumed size distribution in the V1.5 retrieval is assumed to be altitude independent and so it may be less accurate for altitudes above 28 km and below 19 km where the size distribution is more variable. There are other reasons related to cloud contamination, wavelength limitations and the accuracy of both instruments at low aerosol loading.

Monitoring the Variability of the Stratospheric Aerosol Layer over Tomsk in 2016–2018 Based on Lidar Data

2021 ◽  
pp. 61-72
Author(s):  
V. N. Marichev ◽  
◽  
D. A. Bochkovskiia ◽  
Keyword(s):  
Volcanic Eruptions ◽  
Temperature Inversion ◽  
Cold Season ◽  
Stratospheric Aerosol ◽  
Single Frequency ◽  
Winter Period ◽  
Lidar Data ◽  
Aerosol Layer ◽  
Time Data ◽  
Academy Of Sciences

The results of observations of the features of intraannual variability for the vertical structure of background aerosol in the stratosphere over Western Siberia in 2016–2018 are presented and analyzed. Experimental data were obtained at the lidar complex of Zuev Institute of Atmospheric Optics (Siberian Branch, Russian Academy of Sciences) with a receiving mirror diameter of 1 m. The objective of the study is to investigate the dynamics of background stratospheric aerosol, since during this period there were no volcanic eruptions leading to the transport of eruptive aerosol into the stratosphere. The results of the study confirm a stable intraannual cycle of maximum aerosol filling of the stratosphere in winter, a decrease in spring to the minimum, practical absence in summer, and an increase in autumn. At the same time, the variability of stratification and aerosol filling is observed for different years. It was found that aerosol is concentrated in the layer up to 30 km all year round, except for the winter period. It is shown that the vertical aerosol stratification is largely determined by the thermal regime of the tropo- sphere–stratosphere boundary layer. The absence of a pronounced temperature inversion at the tropopause contributes to an increase in the stratosphere–troposphere exchange and, as a result, to the aerosol transport to the stratosphere. This situation is typical of the cold season. For the first time, data on the quantitative content of stratospheric aerosol (its mass concentration) were obtained from single- frequency lidar data.

scholarly journals The Model Intercomparison Project on the climatic response to Volcanic forcing (VolMIP): Experimental design and forcing input data

2016 ◽  
Author(s):  
Davide Zanchettin ◽  
Myriam Khodri ◽  
Claudia Timmreck ◽  
Matthew Toohey ◽  
Anja Schmidt ◽  
...  
Keyword(s):  
Climate Models ◽  
Climate Model ◽  
Initial Conditions ◽  
Volcanic Eruptions ◽  
Stratospheric Aerosol ◽  
Aerosol Layer ◽  
Model Intercomparison ◽  
Climatic Response ◽  
Volcanic Forcing ◽  
Intercomparison Project

Abstract. The enhancement of the stratospheric aerosol layer by volcanic eruptions induces a complex set of responses causing global and regional climate effects on a broad range of timescales. Uncertainties exist regarding the climatic response to strong volcanic forcing identified in coupled climate simulations that contributed to the fifth phase of the Climate Model Intercomparison Project (CMIP5). In order to better understand the sources of these model diversities, the model intercomparison project on the climate response to volcanic forcing (VolMIP) has defined a coordinated set of idealized volcanic perturbation experiments to be carried out in alignment with the CMIP6 protocol. VolMIP provides a common stratospheric aerosol dataset for each experiment to eliminate differences in the applied volcanic forcing, and defines a set of initial conditions to determine how internal climate variability contributes to determining the response. VolMIP will assess to what extent volcanically-forced responses of the coupled ocean-atmosphere system are robustly simulated by state-of-the-art coupled climate models and identify the causes that limit robust simulated behavior, especially differences in the treatment of physical processes. This paper illustrates the design of the idealized volcanic perturbation experiments in the VolMIP protocol and describes the common aerosol forcing input datasets to be used.

scholarly journals Evidence for the predictability of changes in the stratospheric aerosol size following volcanic eruptions of diverse magnitudes using space-based instruments

2020 ◽  
Author(s):  
Larry W. Thomason ◽  
Mahesh Kovilakam ◽  
Anja Schmidt ◽  
Christian von Savigny ◽  
Travis Knepp ◽  
...  
Keyword(s):  
Size Distribution ◽  
Extinction Coefficient ◽  
Volcanic Eruptions ◽  
Stratospheric Aerosol ◽  
Global Climate Models ◽  
Aerosol Size Distribution ◽  
Aerosol Layer ◽  
Aerosol Extinction ◽  
Volcanic Event ◽  
Aerosol Extinction Coefficient

Abstract. An analysis of multiwavelength stratospheric aerosol extinction coefficient data from the Stratospheric Aerosol and Gas Experiment II and III/ISS instruments is used to demonstrate a coherent relationship between the perturbation in extinction coefficient in an eruption's main aerosol layer and an apparent change in aerosol size distribution that spans multiple orders of magnitude in the stratospheric impact of a volcanic event. The relationship is measurement-based and does not rely on assumptions about the aerosol size distribution. We note limitations on this analysis including that the presence of significant amounts of ash in the main aerosol layer may significantly modulate these results. Despite this limitation, these findings represent a unique opportunity to verify the performance of interactive aerosol models used in Global Climate Models and Earth System Model and may suggest an avenue for improving aerosol extinction coefficient measurements from single channel observations such the Optical Spectrograph and Infrared Imager System as they rely on a priori assumptions about particle size.

scholarly journals Evidence for the predictability of changes in the stratospheric aerosol size following volcanic eruptions of diverse magnitudes using space-based instruments

2021 ◽  
Vol 21 (2) ◽  
pp. 1143-1158 ◽  
Author(s):  
Larry W. Thomason ◽  
Mahesh Kovilakam ◽  
Anja Schmidt ◽  
Christian von Savigny ◽  
Travis Knepp ◽  
...  
Keyword(s):  
Extinction Coefficient ◽  
Climate Models ◽  
Single Channel ◽  
Volcanic Eruptions ◽  
Stratospheric Aerosol ◽  
Global Climate Models ◽  
Aerosol Size Distribution ◽  
Aerosol Layer ◽  
Aerosol Extinction ◽  
Aerosol Extinction Coefficient

Abstract. An analysis of multiwavelength stratospheric aerosol extinction coefficient data from the Stratospheric Aerosol and Gas Experiment II and III/ISS instruments is used to demonstrate a coherent relationship between the perturbation in extinction coefficient in an eruption's main aerosol layer and the wavelength dependence of that perturbation. This relationship spans multiple orders of magnitude in the aerosol extinction coefficient of stratospheric impact of volcanic events. The relationship is measurement-based and does not rely on assumptions about the aerosol size distribution. We note limitations on this analysis including that the presence of significant amounts of ash in the main sulfuric acid aerosol layer and other factors may significantly modulate these results. Despite these limitations, the findings suggest an avenue for improving aerosol extinction coefficient measurements from single-channel observations such as the Optical Spectrograph and Infrared Imager System as they rely on a prior assumptions about particle size. They may also represent a distinct avenue for the comparison of observations with interactive aerosol models used in global climate models and Earth system models.

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