N. L. Abraham, A. T. Archibald, N. Bellouin, O. Boucher, P. Braesicke et al.,

O. Morgenstern, F. O. Connor, C. Ord, S. Osprey, K. Pringle et al., Unified Model Documentation Paper No, United Kingdom Chemistry and Aerosol (UKCA) Technical, vol.84

, Description MetUM Version 8.4, Tech. rep., UK Met Office, 2012.

G. P. Ayers, R. W. Gillett, and J. L. Gras, On the vapor pressure of sulfuric acid, Geophys. Res. Lett, vol.7, pp.433-436, 1980.

M. P. Baldwin, L. J. Gray, T. J. Dunkerton, K. Hamilton, P. H. Haynes et al., The Quasi-Biennial Oscillation, p.865

, Rev. Geophys, vol.39, pp.179-229, 2001.

S. Bekki, R. Toumi, and J. A. Pyle, Role of sulphur photochemistry in tropical ozone changes after the eruption of Mount Pinatubo, Nature, vol.362, pp.331-333, 1993.

,

. Preprint, Discussion started, 2020.

S. Bekki, Oxidation of volcanic SO2: A sink for stratospheric OH and H2O, Geophys. Res. Lett, vol.22, pp.913-916, 1995.

S. Bekki, J. A. Pyle, W. Zhong, R. Toumi, J. D. Haigh et al., The role of microphysical and chemical processes in prolonging the climate forcing of the Toba eruption, Geophys. Res. Lett, vol.23, pp.2669-2672, 1996.

K. D. Beyer, A. R. Ravishankara, and E. R. Lovejoy, Measurements of UV refractive indices and densities of H 2 SO 4 /H 2 O and H 2 SO 4 /HNO 3 /H 2 O solutions, J. Geophys. Res, vol.101, issue.D9, pp.14519-14524, 1996.

S. A. Carn, L. Clarisse, and A. J. Prata, Multi-decadal satellite measurements of global volcanic degassing, J. Volcanol. Geoth. Res, vol.875, pp.99-134, 2016.

K. S. Carslaw, B. Luo, and T. Peter, An analytic expression for the composition of aqueous HNO3-H2SO4 stratospheric aerosols including gas phase removal of HNO3, Geophys. Res. Lett, vol.22, pp.1877-1880, 1995.

S. S. Dhomse, K. M. Emmerson, G. W. Mann, N. Bellouin, K. S. Carslaw et al., , p.880

L. W. Thomason, Aerosol microphysics simulations of the Mt. Pinatubo eruption with the UM-UKCA composition-climate model, Atmos. Chem. Phys, vol.14, pp.11221-11246, 2014.

J. M. English, O. B. Toon, M. J. Mills, Y. , and F. , Microphysical simulations of new particle formation in the upper troposphere and lower stratosphere, Atmos. Chem. Phys, vol.11, pp.9303-9322, 2011.

J. M. English, O. B. Toon, and M. J. Mills, Microphysical simulations of large volcanic eruptions: Pinatubo and Toba, J. Geophys

.. Res, , vol.118, pp.1-16, 2013.

K. J. Feierabend, D. K. Havey, S. S. Brown, and V. Vaida, Experimental absolute intensities of the 4?9 and 5?9 O-H stretching overtones of H2SO4, Chem. Phys. Lett, vol.420, pp.438-442, 2006.

C. Gao, A. Robock, and C. Ammann, Volcanic forcing of climate over the past 1500 years: An improved ice core-based index for climate models, J. Geophys. Res, vol.113, p.23111, 2008.

J. L. Gmitro and T. Vermeulen, Vapor -liquid equilibria for aqueous sulfuric acid, AIChE J, vol.10, pp.740-746, 1964.

S. Guo, G. J. Bluth, W. I. Rose, I. M. Watson, and A. J. Prata, Re-evaluation of SO 2 release of the 15 June 1991 Pinatubo eruption using ultraviolet and infrared satellite sensors, Geochem. Geophy. Geosy, vol.5, p.4, 2004.

S. Guo, W. I. Rose, G. J. Bluth, and I. M. Watson, Particles in the great Pinatubo volcanic cloud of, vol.5, p.5003, 1991.

P. Heckendorn, D. Weisenstein, S. Fueglistaler, B. P. Luo, E. Rozanov et al., The impact of geoengineering aerosols on stratospheric temperature and ozone, Environ. Res. Lett, vol.4, p.45108, 2009.

,

R. Hommel, C. Timmreck, and H. F. Graf, The global middle-atmosphere aerosol model MAECHAM5-SAM2: comparison with 900 satellite and in-situ observations, Geosci. Model Dev, vol.4, pp.809-834, 2011.

P. Joeckel, R. Sander, A. Kerkweg, H. Tost, and J. Lelieveld, Technical Note: The Modular Earth Submodel System (MESSy)-a new approach towards Earth System Modeling, Atmos. Chem. Phys, vol.5, pp.433-444, 2005.

M. Kerker, The Scattering of Light and other electromagnetic radiation, Physical Chemistry: A Series of Monographs, vol.16, 1969.

M. Khodri, D. Zanchettin, C. Timmreck, W. Ball, S. Bekki et al., Reconstruction of the Tambora Forcing with Global Aerosol Models: Challenges and Limitations, Stratospheric Aerosol, Volcanic Eruptions and Their Radiative Effects, pp.2016-6515, 2016.

C. Kleinschmitt, O. Boucher, S. Bekki, F. Lott, and U. Platt, The Sectional Stratospheric Sulfate Aerosol module
URL : https://hal.archives-ouvertes.fr/insu-01649782

, within the LMDZ general circulation model: description and evaluation against stratospheric aerosol observations, Geosci. Model Dev, vol.10, pp.3359-3378, 2017.

H. Kokkola, H. Korhonen, K. E. Lehtinen, R. Makkonen, A. Asmi et al., SALSA -a Sectional Aerosol module for Large Scale Applications, Atmos. Chem. Phys, vol.8, pp.2469-2483, 2008.
URL : https://hal.archives-ouvertes.fr/hal-00303206

H. Kokkola, R. Hommel, J. Kazil, U. Niemeier, A. Partanen et al., Aerosol microphysics modules in the framework of the ECHAM5 climate model -intercomparison under stratospheric conditions, Geosci. Model Dev, vol.2, pp.97-112, 2009.

H. Kokkola, T. Kühn, A. Laakso, T. Bergman, K. E. Lehtinen et al.,

L. Romakkaniemi and S. , SALSA2.0: The sectional aerosol module of the aerosol-chemistry-climate model, Geosci. Model Dev, vol.11, pp.3833-3863, 2018.

M. Kulmala and A. Laaksonen, Binary nucleation of water-sulfuric acid system: Comparison of classical theories with different H2SO4 saturation vapor pressures, J. Chem. Phys, vol.93, pp.696-701, 1990.

A. Laakso, H. Kokkola, A. Partanen, U. Niemeier, C. Timmreck et al., , p.925

, Radiative and climate impacts of a large volcanic eruption during stratospheric sulfur geoengineering, Atmos. Chem. Phys, vol.16, pp.305-323, 2016.

J. R. Lane and H. G. Kjaergaard, Calculated electronic transitions in sulfuric acid and implications for its photodissociation in the atmosphere, J. Phys. Chem. A, vol.112, issue.22, pp.4958-4964, 2008.

A. N. Legrande, K. Tsigaridis, and S. E. Bauer, Role of atmospheric chemistry in the climate impacts of stratospheric volcanic 930 injections, Nat. Geosci, vol.9, pp.652-655, 2016.

,

. Preprint, Discussion started, 2020.

X. Liu, R. C. Easter, S. J. Ghan, R. Zaveri, P. Rasch et al., Toward a minimal representation of aerosols in climate models: description and evaluation in the Community Atmosphere Model CAM5, Geosci. Model Dev, vol.5, pp.709-739, 2012.

G. W. Mann, K. S. Carslaw, D. V. Spracklen, D. A. Ridley, P. T. Manktelow et al., Description and evaluation of GLOMAP-mode: a modal global aerosol microphysics model for the UKCA compositionclimate model, Geosci. Model Dev, vol.3, pp.519-551, 2010.

L. Marshall, A. Schmidt, M. Toohey, K. S. Carslaw, G. W. Mann et al., , p.940

J. O. Poulain, V. Robock, A. Rozanov, E. Stenke, A. Sukhodolov et al., Multi-model comparison of the volcanic sulfate deposition from the 1815 eruption of Mt. Tambora, Atmos. Chem. Phys, vol.18, pp.2307-2328, 2018.
URL : https://hal.archives-ouvertes.fr/hal-01630482

E. Martin, C. George, M. , and P. , Densities and Surface Tensions of H2SO4/HNO3/H2O solutions, Geophys. Res. Lett, vol.27, 2000.

Y. Miller, R. B. Gerber, and V. Vaida, Photodissociation yields for vibrationally excited states of sulfuric acid under atmospheric conditions, Geophys. Res. Lett, vol.34, p.16820, 2007.

M. J. Mills, Stratospheric sulfate aerosol: A microphysical model, 1996.

M. J. Mills, O. B. Toon, and G. E. Thomas, Mesospheric sulfate aerosol layer, J. Geophys. Res, vol.110, p.24208, 2005.

M. J. Mills, O. B. Toon, V. Vaida, P. E. Hintze, H. G. Kjaergaard et al., Photolysis of sulfuric acid vapor by visible light as a source of the polar stratospheric CN layer, J. Geophys. Res, vol.110, p.8201, 2005.

M. J. Mills, A. Schmidt, R. Easter, S. Solomon, D. E. Kinnison et al., Global volcanic aerosol properties derived from emissions, 1990.

, Geophys. Res.-Atmos, vol.121, pp.2332-2348, 2016.

M. J. Mills, J. H. Richter, S. Tilmes, B. Kravitz, D. G. Macmartin et al., Radiative and chemical response to interactive stratospheric sulfate aerosols in fully coupled CESM1(WACCM), J Geophys. Res.-Atmos, vol.122, pp.13061-13078, 2017.

S. Mossop, Volcanic Dust Collected at an Altitude of 20 KM, Nature, vol.203, pp.824-827, 1964.

L. O. Muser, G. A. Hoshyaripour, J. Bruckert, A. Horvath, E. Malinina et al., Particle Aging and Aerosol-Radiation Interaction Affect Volcanic Plume Dispersion: Evidence from Raikoke Eruption, Atmos. Chem. Phys. Discuss, 2019.

C. E. Myhre, D. H. Christensen, F. M. Nicolaisen, and C. J. Nielsen, Spectroscopic study of aqueous H2SO4 at different 965 temperatures and compositions: Variations in dissociation and optical properties, Chemistry and Technology, vol.107, 1928.

J. L. Neu, M. J. Prather, and J. E. Penner, Global atmospheric chemistry: Integrating over fractional cloud cover, J. Geophys

.. Res, , vol.112, p.11306, 2007.

U. Niemeier, C. Timmreck, H. Graf, S. Kinne, S. Rast et al., Initial fate of fine ash and sulfur from large volcanic eruptions, Atmos. Chem. Phys, vol.9, pp.9043-9057, 2009.

U. Niemeier, H. Schmidt, and C. Timmreck, The dependency of geoengineered sulfate aerosol on the emission strategy, Atmos. Sci. Lett, vol.12, pp.189-194, 2011.

U. Niemeier and C. Timmreck, What is the limit of climate engineering by stratospheric injection of SO 2 ?, Atmos. Chem. Phys, vol.15, pp.9129-9141, 2015.

L. Oman, A. Robock, G. L. Stenchikov, T. Thordarson, D. Koch et al., Modeling the distribution of the volcanic aerosol cloud from the 1783-1784 Laki eruption, J. Geophys. Res, vol.111, p.12209, 2006.

J. P. Pinto, R. P. Turco, and O. B. Toon, Self-limiting physical and chemical effects in volcanic eruption clouds, J Geophys. Res, vol.980, pp.11165-11174, 1989.

M. Prather, -. Fast, and . Website, , 2012.

R. F. Pueschel, P. B. Russell, D. A. Allen, G. V. Ferry, K. G. Snetsinger et al., Physical and optical properties of the Pinatubo volcanic aerosol: Aircraft observations with impactors and a Sun--tracking photometer, J. Geophys. Res, vol.99, pp.12915-12922, 1994.

A. Robock and M. Matson, Circumglobal transport of the El Chichón volcanic dust cloud, Science, vol.221, pp.195-197, 1983.

A. Robock, C. M. Ammann, L. Oman, D. Shindell, S. Levis et al., Did the Toba volcanic eruption of ?74 ka B.P. produce widespread glaciation?, J. Geophys. Res, vol.114, p.10107, 2009.

E. V. Rozanov, M. E. Schlesinger, N. G. Andronova, F. Yang, S. L. Malyshev et al., , p.990

, Climate/chemistry effects of the Pinatubo volcanic eruption simulated by the UIUC stratosphere/troposphere GCM with interactive photochemistry, J. Geophys. Res, vol.107, p.4594, 2002.

J. H. Seinfeld and S. N. Pandis, Atmospheric Chemistry and Physics: From Air Pollution to Climate Change, 2016.

S. Self, J. Zhao, R. E. Holasek, R. C. Torres, A. J. King et al., The atmospheric impact of the 1991 Mount Pinatubo Eruption, 995 in: Fire and Mud: Eruptions and Lahars of Mount Pinatubo, Geophys. Res. Lett, vol.31, p.20608, 1993.

M. A. Shapiro, R. C. Schnell, F. P. Parungo, S. J. Oltmans, and B. Bodhaine, A: El Chichon volcanic debris in an Arctic tropopause 1000 fold, Geophys. Res. Lett, vol.11, pp.421-424, 1984.

J. Sheng, D. K. Weisenstein, B. Luo, E. Rozanov, A. Stenke et al., Global atmospheric sulfur budget under volcanically quiescent conditions: aerosol-chemistry-climate model predictions and validation, J. Geophys. Res.-Atmos, vol.120, pp.256-276, 2015.

H. M. Steele and P. Hamill, Effects of temperature and humidity on the growth and optical properties of sulphuric acid-water 1005 droplets in the stratosphere, J. Aerosol Sci, vol.12, pp.517-528, 1981.

A. Stenke, M. Schraner, E. Rozanov, T. Egorova, B. Luo et al., The SOCOL version 3.0 chemistry-climate model: description, evaluation, and implications from an advanced transport algorithm, Geosci. Model Dev, vol.6, pp.1407-1427, 2013.

P. Stier, J. Feichter, S. Kinne, S. Kloster, E. Vignati et al., , p.1010

M. Boucher, O. Minikin, A. Petzold, and A. , The aerosol-climate model ECHAM5-HAM, Atmos. Chem. Phys, vol.5, pp.1125-1156, 2005.
URL : https://hal.archives-ouvertes.fr/hal-00327913

T. Sukhodolov, J. Sheng, A. Feinberg, B. Luo, T. Peter et al., Stratospheric aerosol evolution after Pinatubo simulated with a coupled size-resolved aerosol-chemistry-climate model, Geosci. Model Dev, vol.11, pp.2633-2647, 2018.

A. Tabazadeh, O. B. Toon, S. L. Clegg, and P. Hamill, A new parameterization of H2SO4/H2O aerosol composition: Atmospheric implications, Geophys. Res. Lett, vol.24, 1931.

C. Timmreck, H. Graf, and B. Steil, Aerosol chemistry interactions after the Mt. Pinatubo eruption, Volcanism and the Earth's Atmosphere, pp.214-225, 2003.

C. Timmreck and H. Graf, The initial dispersal and radiative forcing of a Northern Hemisphere mid-latitude super volcano: a model study, Atmos. Chem. Phys, vol.6, pp.35-49, 2006.
URL : https://hal.archives-ouvertes.fr/hal-00295818

C. Timmreck, G. W. Mann, V. Aquila, R. Hommel, L. A. Lee et al., The Interactive Stratospheric Aerosol Model Intercomparison Project (ISA-MIP): motivation and experimental design, vol.11, p.1025

, , 2018.

,

M. Toohey, B. Stevens, H. Schmidt, and C. Timmreck, Easy Volcanic Aerosol (EVA v1.0): an idealized forcing generator for climate simulations, Geosci. Model Dev, vol.9, pp.4049-4070, 2016.

M. Toohey and M. Sigl, Volcanic stratospheric sulfur injections and aerosol optical depth from 500 BCE to 1900 CE, Earth Syst

. Sci and . Data, , vol.9, pp.809-831, 2017.

V. Vaida, H. G. Kjaergaard, P. E. Hintze, and D. J. Donaldson, Photolysis of sulfuric acid vapor by visible solar radiation, Science, vol.299, pp.1566-1568, 2003.

H. Vehkamäki, M. Kulmala, I. Napari, K. E. Lehtinen, C. Timmreck et al., An improved parameterization for sulfuric acid-water nucleation rates for tropospheric and stratospheric conditions, J. Geophys. Res, vol.107, issue.D22, p.4622, 2002.

E. Vignati, J. Wilson, and P. Stier, M7: An efficient size-resolved aerosol microphysics module for large-scale aerosol transport models, J. Geophys. Res, vol.109, p.22202, 2004.

D. K. Weisenstein, J. E. Penner, M. Herzog, and X. Liu, Global 2-D intercomparison of sectional and modal aerosol modules, Atmos. Chem. Phys, vol.7, pp.2339-2355, 2007.
URL : https://hal.archives-ouvertes.fr/hal-00302346

O. Wild, X. Zhu, and M. J. Prather, Fast-J: Accurate simulation of in-and below-cloud photolysis in tropospheric chemical 1040 models, J. Atmos. Chem, vol.37, pp.245-282, 2000.

R. E. Young, H. Houben, and O. B. Toon, Radiatively forced dispersion of the Mt. Pinatubo volcanic cloud and induced temperature perturbations in the stratosphere during the first few months following the eruption, Geophys. Res. Lett, vol.21, pp.369-372, 1994.

D. Zanchettin, M. Khodri, C. Timmreck, M. Toohey, A. Schmidt et al., , p.1045

W. T. Bauer, S. E. Bekki, S. Dhomse, S. S. Legrande, A. N. Mann et al., The Model Intercomparison Project on the climatic response to Volcanic forcing (VolMIP): experimental design and forcing input data for CMIP6, Geosci. Model Dev, vol.9, pp.2701-2719, 2016.
URL : https://hal.archives-ouvertes.fr/insu-01368011

Y. Zhu, O. B. Toon, E. J. Jensen, C. G. Bardeen, M. J. Mills et al., Persisting volcanic ash 1050 particles impact stratospheric SO2 lifetime and aerosol optical properties, Nat. Commun, p.2020

,

, UM-UKCA (purple), SOCOL-AER point (green), MAECHAM5-HAM point (gold), LMDZ-S3A band (dark brown) and EVA (red) models. SOCOL-AER and MAECHAM5-HAM band injection experiments are 1070 in green and orange respectively. Vertical dotted line marks date of injection of SO 2

,

. Preprint, Discussion started, 2020.

, Figure 2: Global stratospheric burden of SO 4 in TgS vs time. Vertical dashed black line indicates month of injection

,

, c Author(s) 2020. CC BY 4.0 License. Figure 3: Global stratospheric mean effective radius (Reff) time series. Vertical dotted line marks date of injection of SO 2. The calculation of Reff is weighted by surface aerosol density and gridcell volume, 2020.

,

. Preprint, Discussion started, 2020.

, Easterly phase nudged QBO forcing is used from the observed strength starting with 1982 for two runs (red), and from the observed strength starting with 1991 for three runs (blue). The ensemble mean of the five runs is in black. Vertical dotted line marks date of injection of SO 2, Global stratospheric mean AOD of the 5 CESM-WACCM ensemble runs, vol.8

,

. Preprint, Discussion started, 2020.

, Shaded regions for each model are from ? = 0.9 (lower edge of shaded region) to 0.75 (upper edge of shaded region). The real AOD from each model is also shown (dashed lines). The 1115 dashed lines in this plot are equivalent to the lines in Figure 1. For this plot, the corresponding values of ? from ? used for Eq, Reconstructed global stratospheric AOD time series using Eqs. (1 and 2), vol.9, 2003.

,