Stratospheric Aerosol Optical Depth Merged Data Hub
Perturbations in stratospheric aerosol produced by major volcanic eruptions are one of the primary natural factors affecting climate variability. Reconstructions of past stratospheric aerosol perturbations are important for interpreting records of past climate variability from climate proxy, instrumental or documentary records, and for performing numerical model simulations of past climate.
This data repository holds reconstructions of stratospheric aerosol optical properties for use in climate investigations and simulations. Particularly, this repository provides merged reconstructions, which draw on different published data sets to provide the best and most convenient timeseries for certain applications. It provides aerosol optical depth with global coverage in netcdf format, as well as more compact spatial means (global, hemispheric etc.) in spreadsheet format which may be useful for direct comparison with climate records.
1. The common era
The eVolv2k ice core-based reconstruction of volcanic stratospheric sulfur injection (VSSI) and stratospheric aerosol optical depth (SAOD) covers the period -500 to 1900 CE (Toohey and Sigl, 2017). The time range is limited due to the increasing influence of anthropogenic sulfur deposition to Greenland post 1900. To provide a continuous time series of stratospheric aerosol to present, it is convenient to merge the eVolv2k data with other reconstructions of the 1900 to present. A stratospheric aerosol dataset constructed for use in the CMIP6 historical simulations fits this purpose, since it covers the period 1850-2014. It is constructed using satellite observations from 1979 to present, and a mix of ground-based optical observations, ice cores and volcanological data from 1850-1979.
The merged data product simply stitches together the eVolv2k and CMIP6 time series at the year 1900. The latest revision used eVolv2k version 3 and CMIP6 version 3.
Merged Data:
| Name |
Year Range |
NetCDF Output (.nc) |
Excel Output (.xlsx) |
| Merged eVolv2k/CMIP6 |
-500:2014 |
.nc format |
.xlsx format |
2. Holocene
The HolVol reconstruction covers the period -9500 to 1900 CE (Sigl et al. 2021). It is constructed using a set of ice cores that generally cover this full period, i.e., a smaller sample of cores compared to the eVolv2k reconstruction. Over the period of overlap, eVolv2k and HolVol show negligible systematic biases, however due to the lower sample size, the HolVol estimates are more uncertain. For this reason, for the most accurate time series, a user would likely prefer to use a merged product, that comprises HolVol for the -9500 to -501 period, eVolv2k for -500 to 1900, and CMIP6 for 1901 to present.
The latest version uses HolVol version 1, eVolv2k version 3 and CMIP6 version 3.
Merged Data:
| Name |
Year Range |
NetCDF Output (.nc) |
Excel Output (.xlsx) |
| Merged HolVol, eVolv2k, CMIP6 |
-9500:2014 |
.nc format |
.xlsx format |
References:
a. 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.
b. Toohey, Matthew; Sigl, Michael (2019). Reconstructed volcanic stratospheric sulfur injections and aerosol optical depth, 500 BCE to 1900 CE, version 3. World Data Center for Climate (WDCC) at DKRZ. https://doi.org/10.26050/WDCC/eVolv2k_v3
c. Sigl, Michael; Toohey, Matthew; McConnell, Joseph R; Cole-Dai, Jihong; Severi, Mirko (2021): HolVol: Reconstructed volcanic stratospheric sulfur injections and aerosol optical depth for the Holocene (9500 BCE to 1900 CE). PANGAEA, https://doi.org/10.1594/PANGAEA.928646
d. Sigl, M., Toohey, M., McConnell, J. R., Cole-Dai, J., and Severi, M.: Volcanic stratospheric sulfur injections and aerosol optical depth during the Holocene (past 11,500 years) from a bipolar ice core array, Earth Syst. Sci. Data Discuss. [preprint], https://doi.org/10.5194/essd-2021-422, in review, 2022.
e. Luo, B.: Release Notes Stratospheric Aerosol Radiative Forcing and SAD version v4.0.01850 - 2016, ftp://iacftp.ethz.ch/pub_read/luo/CMIP6_SAD_radForcing_v4.0.0/Release_note_v4.0.0.pdf, 2018.
Contact:
For webpage upkeep: C.J. Ogilvie, cfo188@usask.ca
For EVA and data questions: Dr. Matthew Toohey, matthew.toohey@usask.ca
This page was created by C.J. Ogilvie. It was created under the supervision of Dr. Matthew Toohey, for the Institute of Space and Atmospheric Studies at the University of Saskatchewan. Last updated April 29th, 2022.