Correcting the record of volcanic stratospheric aerosol impact: Nabro and Sarychev Peak

Abstract. Volcanic eruptions impact climate through the injection of sulfur dioxide (SO2), which is oxidized to form sulfuric acid aerosol particles that can enhance the stratospheric aerosol optical depth (SAOD). Besides large-magnitude eruptions, moderate-magnitude eruptions such as Kasatochi in 2008 and Sarychev Peak in 2009 can have a significant impact on stratospheric aerosol and hence climate. However, uncertainties remain in quantifying the atmospheric and climatic impacts of the 2009 Sarychev Peak eruption due to limitations in previous model representations of volcanic aerosol microphysics and particle size, whilst biases have been identified in satellite estimates of post-eruption SAOD. In addition, the 2009 Sarychev Peak eruption co-injected hydrogen chloride (HCl) alongside SO2, whose potential stratospheric chemistry impacts have not been investigated to date. We present a study of the stratospheric SO2-particle-HCl processing and impacts following Sarychev Peak eruption, using the CESM1(WACCM)-CARMA sectional aerosol microphysics model (with no a priori assumption on particle size). The Sarychev Peak 2009 eruption injected 0.9 Tg of SO2 into the upper troposphere and lower stratosphere (UTLS), enhancing the aerosol load in the Northern hemisphere. The post-eruption evolution of the volcanic SO2 in space and time are well reproduced by the model when compared to IASI (Infrared Atmospheric Sounding Interferometer) satellite data. Co-injection of 27 Gg HCl causes a lengthening of the SO2 lifetime and a slight delay in the formation of aerosols, and acts to enhance the destruction of stratospheric ozone and mono-nitrogen oxides (NOx) compared to the simulation with volcanic SO2 only. We therefore highlight the need to account for volcanic halogen chemistry when simulating the impact of eruptions such as Sarychev on stratospheric chemistry. The model-simulated evolution of effective radius (reff), reflects new particle formation followed by particle growth that enhances reff to reach up to 0.2 µm on zonal average. Comparisons of the model-simulated particle number and size-distributions to balloon-borne in-situ stratospheric observations over Kiruna, Sweden, in August and September 2009, and over Laramie, U.S.A., in June and November 2009 show good agreement and quantitatively confirms the post-eruption particle enhancement. We show that the model-simulated SAOD is consistent with that derived from OSIRIS (Optical Spectrograph and InfraRed Imager System) when both the saturation bias of OSIRIS and the fact that extinction profiles may terminate well above the tropopause are taken into account. Previous modelling studies (involving assumptions on particle size) that reported agreement to (biased) post-eruption estimates of SAOD derived from OSIRIS likely underestimated the climate impact of the 2009 Sarychev Peak eruption.

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Lidar ratios of stratospheric volcanic ash and sulfate aerosols retrieved from CALIOP measurements

10.5194/acp-2016-1173 ◽

2017 ◽

Author(s):

Andrew T. Prata ◽

Stuart A. Young ◽

Steven T. Siems ◽

Michael J. Manton

Keyword(s):

Volcanic Ash ◽

Stratospheric Aerosol ◽

Orthogonal Polarization ◽

Volcanic Aerosol ◽

Time Period ◽

Lidar Ratio ◽

The Mean ◽

Lidar Observations ◽

532 Nm ◽

Sarychev Peak

Abstract. We apply a two-way transmittance constraint to nighttime CALIOP (Cloud-Aerosol Lidar with Orthogonal Polarization) observations of volcanic aerosol layers to retrieve estimates of the particulate lidar ratio (Sp) at 532 nm. This technique is applied to three volcanic eruption case studies that were found to have injected aerosols directly into the stratosphere. Numerous lidar observations permitted characterisation of the optical and geometric properties of the volcanic aerosol layers over a time period of 1–2 weeks. For the volcanic ash layers produced by the Puyehue-Cordón Caulle eruption (June 2011) we obtain mean and median particulate lidar ratios of 72 ± 14 sr and 70 sr, respectively. For the sulfates produced by Kasatochi (August 2008) and Sarychev Peak (June 2009), the mean of the retrieved lidar ratios were 68 ± 21 sr (median 62 sr) and 66 ± 15 sr (median 61 sr), respectively. The layer-integrated volume depolarisation ratios (∂v) observed for the Puyehue ash layers (∂v = 0.28 ± 0.03) were much larger than those found for the sulfate layers produced by the Kasatochi (∂v = 0.08 ± 0.03) and Sarychev (∂v = 0.05 ± 0.04) eruptions. However, for the Sarychev layers we observe an exponential decay (e-folding time of 1 week) in ∂v with time from 0.25 to 0.05. The layer-integrated attenuated colour ratios for the Puyehue ash layers (χ' = 0.54 ± 0.07) were also larger than what was observed for the Kasatochi (χ' = 0.35 ± 0.07) and Sarychev (χ' = 0.32 ± 0.07) sulfate layers, indicating that the Puyehue ash layers were generally composed of larger particles. These observations are particularly relevant to the new stratospheric aerosol subtyping classification scheme, which has been incorporated into version 4 of the level 2 CALIPSO data products.

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Lidar Observations of Aerosol Disturbances of the Stratosphere over Tomsk (56.5∘N;85.0∘E) in Volcanic Activity Period 2006–2011

International Journal of Optics ◽

10.1155/2012/786295 ◽

2012 ◽

Vol 2012 ◽

pp. 1-10 ◽

Cited By ~ 7

Author(s):

Oleg E. Bazhenov ◽

Vladimir D. Burlakov ◽

Sergey I. Dolgii ◽

Aleksey V. Nevzorov

Keyword(s):

Volcanic Activity ◽

Volcanic Eruptions ◽

Stratospheric Aerosol ◽

Optical Characteristics ◽

Activity Period ◽

Aerosol Layer ◽

Lidar Measurements ◽

The Vertical Distribution ◽

Sarychev Peak

The lidar measurements (Tomsk:56.5∘N;85.0∘E) of the optical characteristics of the stratospheric aerosol layer (SAL) in the volcanic activity period 2006–2011 are summarized and analyzed. The background SAL state with minimum aerosol content, observed since 1997 under the conditions of long-term volcanically quiet period, was interrupted in October 2006 by series of explosive eruptions of volcanoes of Pacific Ring of Fire: Rabaul (October 2006, New Guinea); Okmok and Kasatochi (July-August 2008, Aleutian Islands); Redoubt (March-April 2009, Alaska); Sarychev Peak (June 2009, Kuril Islands); Grimsvötn (May 2011, Iceland). A short-term and minor disturbance of the lower stratosphere was also observed in April 2010 after eruption of the Icelandic volcano Eyjafjallajokull. The developed regional empirical model of the vertical distribution of background SAL optical characteristics was used to identify the periods of elevated stratospheric aerosol content after each of the volcanic eruptions. Trends of variations in the total ozone content are also considered.

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Lidar ratios of stratospheric volcanic ash and sulfate aerosols retrieved from CALIOP measurements

Atmospheric Chemistry and Physics ◽

10.5194/acp-17-8599-2017 ◽

2017 ◽

Vol 17 (13) ◽

pp. 8599-8618 ◽

Cited By ~ 18

Author(s):

Andrew T. Prata ◽

Stuart A. Young ◽

Steven T. Siems ◽

Michael J. Manton

Keyword(s):

Volcanic Ash ◽

Satellite Observation ◽

Stratospheric Aerosol ◽

Orthogonal Polarization ◽

Observation Data ◽

Volcanic Aerosol ◽

Time Period ◽

Lidar Ratio ◽

Sarychev Peak

Abstract. We apply a two-way transmittance constraint to nighttime CALIOP (Cloud-Aerosol Lidar with Orthogonal Polarization) observations of volcanic aerosol layers to retrieve estimates of the particulate lidar ratio (Sp) at 532 nm. This technique is applied to three volcanic eruption case studies that were found to have injected aerosols directly into the stratosphere. Numerous lidar observations permitted characterization of the optical and geometric properties of the volcanic aerosol layers over a time period of 1–2 weeks. For the volcanic ash-rich layers produced by the Puyehue-Cordón Caulle eruption (June 2011), we obtain mean and median particulate lidar ratios of 69 ± 13 sr and 67 sr, respectively. For the sulfate-rich aerosol layers produced by Kasatochi (August 2008) and Sarychev Peak (June 2009), the means of the retrieved lidar ratios were 66 ± 19 sr (median 60 sr) and 63 ± 14 sr (median 59 sr), respectively. The 532 nm layer-integrated particulate depolarization ratios (δp) observed for the Puyehue layers (δp = 0.33 ± 0.03) were much larger than those found for the volcanic aerosol layers produced by the Kasatochi (δp = 0.09 ± 0.03) and Sarychev (δp = 0.05 ± 0.04) eruptions. However, for the Sarychev layers we observe an exponential decay (e-folding time of 3.6 days) in δp with time from 0.27 to 0.03. Similar decreases in the layer-integrated attenuated colour ratios with time were observed for the Sarychev case. In general, the Puyehue layers exhibited larger colour ratios (χ′ = 0.53 ± 0.07) than what was observed for the Kasatochi (χ′ = 0.35 ± 0.07) and Sarychev (χ′ = 0.32 ± 0.07) layers, indicating that the Puyehue layers were generally composed of larger particles. These observations are particularly relevant to the new stratospheric aerosol subtyping classification scheme, which has been incorporated into version 4 of the level 2 CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation) data products.

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Model simulations of the chemical and aerosol microphysical evolution of the Sarychev Peak 2009 eruption cloud compared to in situ and satellite observations

Atmospheric Chemistry and Physics ◽

10.5194/acp-18-3223-2018 ◽

2018 ◽

Vol 18 (5) ◽

pp. 3223-3247 ◽

Cited By ~ 4

Author(s):

Thibaut Lurton ◽

Fabrice Jégou ◽

Gwenaël Berthet ◽

Jean-Baptiste Renard ◽

Lieven Clarisse ◽

...

Keyword(s):

Particle Size ◽

Climate Model ◽

Stratospheric Ozone ◽

Volcanic Eruptions ◽

Climate Impact ◽

Stratospheric Aerosol ◽

Stratospheric Chemistry ◽

The Impact ◽

Sarychev Peak

Abstract. Volcanic eruptions impact climate through the injection of sulfur dioxide (SO2), which is oxidized to form sulfuric acid aerosol particles that can enhance the stratospheric aerosol optical depth (SAOD). Besides large-magnitude eruptions, moderate-magnitude eruptions such as Kasatochi in 2008 and Sarychev Peak in 2009 can have a significant impact on stratospheric aerosol and hence climate. However, uncertainties remain in quantifying the atmospheric and climatic impacts of the 2009 Sarychev Peak eruption due to limitations in previous model representations of volcanic aerosol microphysics and particle size, whilst biases have been identified in satellite estimates of post-eruption SAOD. In addition, the 2009 Sarychev Peak eruption co-injected hydrogen chloride (HCl) alongside SO2, whose potential stratospheric chemistry impacts have not been investigated to date. We present a study of the stratospheric SO2–particle–HCl processing and impacts following Sarychev Peak eruption, using the Community Earth System Model version 1.0 (CESM1) Whole Atmosphere Community Climate Model (WACCM) – Community Aerosol and Radiation Model for Atmospheres (CARMA) sectional aerosol microphysics model (with no a priori assumption on particle size). The Sarychev Peak 2009 eruption injected 0.9 Tg of SO2 into the upper troposphere and lower stratosphere (UTLS), enhancing the aerosol load in the Northern Hemisphere. The post-eruption evolution of the volcanic SO2 in space and time are well reproduced by the model when compared to Infrared Atmospheric Sounding Interferometer (IASI) satellite data. Co-injection of 27 Gg HCl causes a lengthening of the SO2 lifetime and a slight delay in the formation of aerosols, and acts to enhance the destruction of stratospheric ozone and mono-nitrogen oxides (NOx) compared to the simulation with volcanic SO2 only. We therefore highlight the need to account for volcanic halogen chemistry when simulating the impact of eruptions such as Sarychev on stratospheric chemistry. The model-simulated evolution of effective radius (reff) reflects new particle formation followed by particle growth that enhances reff to reach up to 0.2 µm on zonal average. Comparisons of the model-simulated particle number and size distributions to balloon-borne in situ stratospheric observations over Kiruna, Sweden, in August and September 2009, and over Laramie, USA, in June and November 2009 show good agreement and quantitatively confirm the post-eruption particle enhancement. We show that the model-simulated SAOD is consistent with that derived from the Optical Spectrograph and InfraRed Imager System (OSIRIS) when both the saturation bias of OSIRIS and the fact that extinction profiles may terminate well above the tropopause are taken into account. Previous modelling studies (involving assumptions on particle size) that reported agreement with (biased) post-eruption estimates of SAOD derived from OSIRIS likely underestimated the climate impact of the 2009 Sarychev Peak eruption.

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Isotopic studies of the sulfur component of the stratospheric aerosol layer

Tellus ◽

10.3402/tellusa.v26i1-2.9781 ◽

1974 ◽

Vol 26 (1-2) ◽

pp. 222-234 ◽

Cited By ~ 50

Author(s):

A. W. Castleman Jr. ◽

H. R. Munkelwitz ◽

B. Manowitz

Keyword(s):

Stratospheric Aerosol ◽

Aerosol Layer ◽

Isotopic Studies

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Investigation of Ionospheric Response to June 2009 Sarychev Peak Volcano Eruption

Remote Sensing ◽

10.3390/rs13040638 ◽

2021 ◽

Vol 13 (4) ◽

pp. 638

Author(s):

Nikolay Shestakov ◽

Alexander Orlyakovskiy ◽

Natalia Perevalova ◽

Nikolay Titkov ◽

Danila Chebrov ◽

...

Keyword(s):

Acoustic Mode ◽

Global Navigation Satellite Systems ◽

Electron Content ◽

Field Zone ◽

Ionospheric Response ◽

Satellite Systems ◽

Volcano Eruption ◽

Close Proximity ◽

Global Navigation Satellite ◽

Sarychev Peak

Global Navigation Satellite Systems have been extensively used to investigate the ionosphere response to various natural and man-made phenomena for the last three decades. However, ionospheric reaction to volcano eruptions is still insufficiently studied and understood. In this work we analyzed the ionospheric response to the 11–16 June 2009 VEI class 4 Sarychev Peak volcano eruption by using surrounding Russian and Japanese GPS networks. Prominent covolcanictotal electron content (TEC)ionospheric disturbances (CVIDs) with amplitudes and periods ranged between 0.03–0.15 TECU and 2.5–4.5 min were discovered for the three eruptive events occurred at 18:51 UT, 14 June; at 01:15 and 09:18 UT, 15 June 2009. The estimates of apparent CVIDs velocities vary within 700–1000 m/s in the far-field zone (300–900 km to the southwest from the volcano) and 1300–1800 m/s in close proximity toSarychev Peak. The characteristics of the observed TEC variations allow us to attribute them to acoustic mode. The south-southwestward direction is preferred for CVIDs propagation. We concluded that the ionospheric response to a volcano eruption is mainly determined by a ratio between explosion strength and background ionization level. Some evidence of secondary (F2-layer) CVIDs’ source eccentric location were obtained.

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Updated and outdated reservations about research into stratospheric aerosol injection

Climatic Change ◽

10.1007/s10584-021-03017-z ◽

2021 ◽

Vol 164 (3-4) ◽

Author(s):

Wake Smith ◽

Claire Henly

Keyword(s):

Recent Literature ◽

Early Stage ◽

Stratospheric Aerosol ◽

Research Community ◽

Slippery Slope ◽

Lock In ◽

Stratospheric Aerosol Injection

AbstractIn this paper, we seek to ground discussions of the governance of stratospheric aerosol injection research in recent literature about the field including an updated understanding of the technology’s deployment logistics and scale, pattern of effects, and research pathways. Relying upon this literature, we evaluate several common reservations regarding the governance of pre-deployment research and testing including covert deployment, technological lock-in, weaponization, slippery slope, and the blurry line between research and deployment. We conclude that these reservations are no longer supported by literature. However, we do not argue that there is no reason for concern. Instead, we enumerate alternative bases for caution about research into stratospheric aerosol injection which are supported by an up-to-date understanding of the literature. We conclude that in order to establish the correct degree and type of governance for stratospheric aerosol injection research, the research community must focus its attention on these well-grounded reservations. However, while these reservations are supported and warrant further attention, we conclude that none currently justifies restrictive governance of early-stage stratospheric aerosol injection research.

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Differences in the Evolution of Pyrocumulonimbus and Volcanic Stratospheric Plumes as Observed by CATS and CALIOP Space-Based Lidars

Atmosphere ◽

10.3390/atmos11101035 ◽

2020 ◽

Vol 11 (10) ◽

pp. 1035

Author(s):

Kenneth Christian ◽

John Yorks ◽

Sampa Das

Keyword(s):

Pacific Northwest ◽

Stratospheric Aerosol ◽

Volcanic Aerosol ◽

Volcanic Plumes ◽

Size And Shape ◽

Altitude Dependence ◽

Volcanic Events ◽

Spatial Propagation ◽

Depolarization Ratios

Recent fire seasons have featured volcanic-sized injections of smoke aerosols into the stratosphere where they persist for many months. Unfortunately, the aging and transport of these aerosols are not well understood. Using space-based lidar, the vertical and spatial propagation of these aerosols can be tracked and inferences can be made as to their size and shape. In this study, space-based CATS and CALIOP lidar were used to track the evolution of the stratospheric aerosol plumes resulting from the 2019–2020 Australian bushfire and 2017 Pacific Northwest pyrocumulonimbus events and were compared to two volcanic events: Calbuco (2015) and Puyehue (2011). The pyrocumulonimbus and volcanic aerosol plumes evolved distinctly, with pyrocumulonimbus plumes rising upwards of 10 km after injection to altitudes of 30 km or more, compared to small to modest altitude increases in the volcanic plumes. We also show that layer-integrated depolarization ratios in these large pyrocumulonimbus plumes have a strong altitude dependence with more irregularly shaped particles in the higher altitude plumes, unlike the volcanic events studied.

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Improved tropospheric and stratospheric sulfur cycle in the aerosol–chemistry–climate model SOCOL-AERv2

Geoscientific Model Development ◽

10.5194/gmd-12-3863-2019 ◽

2019 ◽

Vol 12 (9) ◽

pp. 3863-3887 ◽

Cited By ~ 2

Author(s):

Aryeh Feinberg ◽

Timofei Sukhodolov ◽

Bei-Ping Luo ◽

Eugene Rozanov ◽

Lenny H. E. Winkel ◽

...

Keyword(s):

Climate Model ◽

Model Performance ◽

Stratospheric Aerosol ◽

Sulfur Cycle ◽

Sulfate Aerosol ◽

Tropospheric Chemistry ◽

Sulfur Deposition ◽

Aerosol Chemistry ◽

Deposition Fluxes ◽

Aerosol Model

Abstract. SOCOL-AERv1 was developed as an aerosol–chemistry–climate model to study the stratospheric sulfur cycle and its influence on climate and the ozone layer. It includes a sectional aerosol model that tracks the sulfate particle size distribution in 40 size bins, between 0.39 nm and 3.2 µm. Sheng et al. (2015) showed that SOCOL-AERv1 successfully matched observable quantities related to stratospheric aerosol. In the meantime, SOCOL-AER has undergone significant improvements and more observational datasets have become available. In producing SOCOL-AERv2 we have implemented several updates to the model: adding interactive deposition schemes, improving the sulfate mass and particle number conservation, and expanding the tropospheric chemistry scheme. We compare the two versions of the model with background stratospheric sulfate aerosol observations, stratospheric aerosol evolution after Pinatubo, and ground-based sulfur deposition networks. SOCOL-AERv2 shows similar levels of agreement as SOCOL-AERv1 with satellite-measured extinctions and in situ optical particle counter (OPC) balloon flights. The volcanically quiescent total stratospheric aerosol burden simulated in SOCOL-AERv2 has increased from 109 Gg of sulfur (S) to 160 Gg S, matching the newly available satellite estimate of 165 Gg S. However, SOCOL-AERv2 simulates too high cross-tropopause transport of tropospheric SO2 and/or sulfate aerosol, leading to an overestimation of lower stratospheric aerosol. Due to the current lack of upper tropospheric SO2 measurements and the neglect of organic aerosol in the model, the lower stratospheric bias of SOCOL-AERv2 was not further improved. Model performance under volcanically perturbed conditions has also undergone some changes, resulting in a slightly shorter volcanic aerosol lifetime after the Pinatubo eruption. With the improved deposition schemes of SOCOL-AERv2, simulated sulfur wet deposition fluxes are within a factor of 2 of measured deposition fluxes at 78 % of the measurement stations globally, an agreement which is on par with previous model intercomparison studies. Because of these improvements, SOCOL-AERv2 will be better suited to studying changes in atmospheric sulfur deposition due to variations in climate and emissions.

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