The eVolv2k database includes estimates of the magnitudes and approximate source latitudes of major volcanic stratospheric sulfur injection (VSSI) events from 500 BCE to 1900 CE. The VSSI estimates incorporate recent improvements to the ice core records in terms of synchronization and dating, refinements to the methods used to estimate VSSI from ice core records, and includes estimates of the random uncertainties in VSSI values. Ice core-derived volcanic sulfate deposition composites for Antarctica (Sigl et al., 2014) and Greenland (Sigl et al., 2015, Zielinski et al., 1995) are scaled to volcanic stratospheric sulfur injection based on a method similar to that of Gao et al. (2007). More details are described by Toohey and Sigl (2017). Compared to version 2, this update includes reassignment of eruption region for minor events in 1654, 1414, 1381, 688, 379 and -430. Also, minimum flux threshold adjusted downwards so as to include small Greenland flux for events in 1463, -190 and -430. Finally, events with 0 VSSI removed. In addition, a reconstruction of stratospheric aerosol optical depth (AOD) using the VSSI estimates and the EVA v1.2 volcanic forcing generator (Toohey et al., 2016) is provided. Complete optical properties (extinction, single scattering albedo, scattering asymmetry factor) as a function of height, latitude and time can be produced using the eVolv2k VSSI database and the EVA forcing generator. EVA version 1.2 includes a fix of a minor bug which affected the spatiotemporal distribution of AOD, most notably for extratropical eruptions. Gao, C., Oman, L., Robock, A. and Stenchikov, G. L.: Atmospheric volcanic loading derived from bipolar ice cores: Accounting for the spatial distribution of volcanic deposition, J. Geophys. Res., 112(D9), doi:10.1029/2006JD007461, 2007. Sigl, M., Winstrup, M., McConnell, J. R., Welten, K. C., Plunkett, G., Ludlow, F., Büntgen, U., Caffee, M., Chellman, N., Dahl-Jensen, D., Fischer, H., Kipfstuhl, S., Kostick, C., Maselli, O. J., Mekhaldi, F., Mulvaney, R., Muscheler, R., Pasteris, D. R., Pilcher, J. R., Salzer, M., Schüpbach, S., Steffensen, J. P., Vinther, B. M. and Woodruff, T. E.: Timing and climate forcing of volcanic eruptions for the past 2,500 years, Nature, 523, 543¿549, doi:10.1038/nature14565, 2015. Sigl, M., McConnell, J. R., Toohey, M., Curran, M., Das, S. B., Edwards, R., Isaksson, E., Kawamura, K., Kipfstuhl, S., Krüger, K., Layman, L., Maselli, O. J., Motizuki, Y., Motoyama, H., Pasteris, D. R. and Severi, M.: Insights from Antarctica on volcanic forcing during the Common Era, Nat. Clim. Chang., 4, 693-697, doi:10.1038/nclimate2293, 2014. Toohey, M. and Sigl, M.: Volcanic stratospheric sulfur injections and aerosol optical depth from 500 BCE to 1900 CE, Earth Syst. Sci. Data, 9(2), 809–831, doi:10.5194/essd-9-809-2017, 2017. Toohey, M., Stevens, B., Schmidt, H. and Timmreck, C.: Easy Volcanic Aerosol (EVA v1.0): an idealized forcing generator for climate simulations, Geosci. Model Dev., 9(11), 4049–4070, doi:10.5194/GMD-9-4049-2016, 2016.

The eVolv2k database includes estimates of the magnitudes and approximate source latitudes of major volcanic stratospheric sulphur injection (VSSI) events from 500 BCE to 1900 CE. The VSSI estimates incorporate recent improvements to the ice core records in terms of synchronization and dating, refinements to the methods used to estimate VSSI from ice core records, and includes first estimates of the random uncertainties in VSSI values. Ice core-derived volcanic sulfate deposition composites for Antarctica (Sigl et al., 2014) and Greenland (Sigl et al., 2015, Zielinski et al., 1995) are scaled to volcanic stratospheric sulfur injection based on a method similar to that of Gao et al. (2007). More details to be published in a forthcoming article (Toohey and Sigl, in prep). Compared to version 1, this version (1) contains estimates of the random error in the VSSI estimates, (2) includes a clarification regarding the format of years in the BCE period by including both years BCE/CE and according to the ISO 8601 standard (which includes a year 0), and (3) includes some minor modifications to the VSSI values. In addition, a reconstruction of stratospheric aerosol optical depth (AOD) using the VSSI estimates and the EVA v1 volcanic forcing generator (Toohey et al., 2016) is provided. Complete optical properties (extinction, single scattering albedo, scattering asymmetry factor) as a function of height, latitude and time can be produced using the eVolv2k VSSI database and the EVA forcing generator. Gao, C., Oman, L., Robock, A. and Stenchikov, G. L.: Atmospheric volcanic loading derived from bipolar ice cores: Accounting for the spatial distribution of volcanic deposition, J. Geophys. Res., 112(D9), doi:10.1029/2006JD007461, 2007. Sigl, M., Winstrup, M., McConnell, J. R., Welten, K. C., Plunkett, G., Ludlow, F., Büntgen, U., Caffee, M., Chellman, N., Dahl-Jensen, D., Fischer, H., Kipfstuhl, S., Kostick, C., Maselli, O. J., Mekhaldi, F., Mulvaney, R., Muscheler, R., Pasteris, D. R., Pilcher, J. R., Salzer, M., Schüpbach, S., Steffensen, J. P., Vinther, B. M. and Woodruff, T. E.: Timing and climate forcing of volcanic eruptions for the past 2,500 years, Nature, 523, 543¿549, doi:10.1038/nature14565, 2015. Sigl, M., McConnell, J. R., Toohey, M., Curran, M., Das, S. B., Edwards, R., Isaksson, E., Kawamura, K., Kipfstuhl, S., Krüger, K., Layman, L., Maselli, O. J., Motizuki, Y., Motoyama, H., Pasteris, D. R. and Severi, M.: Insights from Antarctica on volcanic forcing during the Common Era, Nat. Clim. Chang., 4, 693-697, doi:10.1038/nclimate2293, 2014. Toohey, M. and Sigl, M.: Volcanic stratospheric sulphur injections and aerosol optical depth from 500 BCE to 1900 CE, in preparation. Toohey, M., Stevens, B., Schmidt, H. and Timmreck, C.: Easy Volcanic Aerosol (EVA v1.0): an idealized forcing generator for climate simulations, Geosci. Model Dev., 9(11), 4049–4070, doi:10.5194/GMD-9-4049-2016, 2016. Zielinski, G. A.: Stratospheric loading and optical depth estimates of explosive volcanism over the last 2100 years derived from the Greenland Ice Sheet Project 2 ice core, J. Geophys. Res., 100(D10), 20937–20955, doi:10.1029/95JD01751, 1995.

This dataset contains ice core-based estimates of volcanic stratospheric sulfur injections covering the years 500 BCE to 1900 CE. Ice core-derived volcanic sulfate deposition composites for Antarctica (Sigl et al., 2014) and Greenland (Sigl et al., 2015) are scaled to volcanic stratospheric sulfur injection based on a method similar to that of Gao et al., (2007). Sigl, M., Winstrup, M., McConnell, J. R., Welten, K. C., Plunkett, G., Ludlow, F., Büntgen, U., Caffee, M., Chellman, N., Dahl-Jensen, D., Fischer, H., Kipfstuhl, S., Kostick, C., Maselli, O. J., Mekhaldi, F., Mulvaney, R., Muscheler, R., Pasteris, D. R., Pilcher, J. R., Salzer, M., Schüpbach, S., Steffensen, J. P., Vinther, B. M. and Woodruff, T. E.: Timing and climate forcing of volcanic eruptions for the past 2,500 years, Nature, 523, 543-549, doi:10.1038/nature14565, 2015. Sigl, M., McConnell, J. R., Toohey, M., Curran, M., Das, S. B., Edwards, R., Isaksson, E., Kawamura, K., Kipfstuhl, S., Krüger, K., Layman, L., Maselli, O. J., Motizuki, Y., Motoyama, H., Pasteris, D. R. and Severi, M.: Insights from Antarctica on volcanic forcing during the Common Era, Nat. Clim. Chang., 4, 693-697, doi:10.1038/nclimate2293, 2014. Gao, C., Oman, L., Robock, A. and Stenchikov, G. L.: Atmospheric volcanic loading derived from bipolar ice cores: Accounting for the spatial distribution of volcanic deposition, J. Geophys. Res., 112(D9), doi:10.1029/2006JD007461, 2007.

VIKING20X-JRA-short (Biastoch et al., 2021) is part of a series of VIKING20X simulations under JRA55-do atmospheric forcing. It is based on a restart from a pre-spun experiment in 1980 (VIKING20X-CORE; see Biastoch et al., 2021) and integrated for the period 1980 to 2019 in the framework of the RACE–Synthesis: Regional Atlantic Circulation and Global Change (https://race-synthese.de). The applied atmospheric forcing JRA55-do (Tsujino et al., 2020, http://doi.org/10.5194/gmd-13-3643-2020) builds on the Japanese reanalysis product JRA-55 with improvements through the implementation of satellite and several other reanalysis products. Details of the Configuration: - eddy-rich 1/20° nest using the two-way nesting technique Adaptive Grid Refinement In Fortran (AGRIF; http://doi.org/10.1016/j.cageo.2007.01.009) that covers the Atlantic Ocean from 33.5° S to ∼65° N embedded in a 1/4° resolution global grid - initialization from a pre-spun experiment in 1980 - time step refinement factor 3 between host and nest - momentum advection scheme in vector form with Hollingsworth correction, conserving both energy and enstrophy - tracer advection as two-step flux corrected transport, total variance dissipation scheme - linearized filtered free surface - weak sea surface salinity restoring towards Levitus WOA98 (piston velocity 12.2 m/yr), suppressed under sea-ice - thermodynamic, dynamic sea-ice model LIM2 (https://doi.org/10.1029/97JC00480) with viscous-plastic rheology - turbulent kinetic energy scheme - bi-Laplacian lateral viscosity - non-linear bottom friction Note of advise on re-using the provided simulation output data We recommend to only use the high-resolution simulation output data from the 1/20 degree nested region for any analysis (nest file names "1_VIKING20X.L46-KKG36107B_*.nc"). The simulation was designed to improve the understanding of specific key processes in the Atlantic Ocean and their effect on the large scale and inter-hemispheric circulation in the Atlantic. The simulation results can only be interpreted in this context and are not necessarily applicable to other arbitrary research questions on ocean and climate dynamics. In particular, the output fields of the global simulation at coarser resolution (host file names "VIKING20X.L46-KKG36107B_*.nc") must be understood as an interactive boundary condition to the focus region of the nest and are here provided for completeness only. For questions in this regard we recommend to contact datamanagement@geomar.de and generally encourage potential users to reach out to us for clarification. A detailed description of the configuration and experiments is given in Biastoch et al. (2021): Biastoch, A., F. U. Schwarzkopf, K. Getzlaff, S. Rühs, T. Martin, M. Scheinert, T. Schulzki, P. Handmann, R. Hummels, and C. W. Böning, 2021, Regional Imprints of Changes in the Atlantic Meridional Overturning Circulation in the Eddy-rich Ocean Model VIKING20X, Ocean. Sci., 17, 1177–1211, http://doi.org/10.5194/os-17-1177-2021