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Stratospheric volcanic SO2 emissions and aerosol optical properties#

Key contacts#

  • Names: Thomas Aubry
  • Emails: t.aubry@exeter.ac.uk

Testing versions of the stratospheric volcanic SO2 emissions and aerosol optical properties are available on the ESGF. These versions are for testing only, do not use them for any simluations you're not willing to throw away.

Documentation on the dataset is hosted externally. This contains a detailed dive into the data. In contrast, this page provides an overview and some key, CMIP-specific information.

If you find any issues, please contribute to the discussion on GitHub.

Summary#

Source IDs for CMIP7 phases#

The source ID that identifies the dataset to use in the different phases of CMIP7 is given below.

Testing#

For the testing phase of CMIP7, use data with the source ID UOEXETER-CMIP-1-2-0

This data is for testing (both of the forcing data and of modelling workflows) only. Production simulations should not be started based on any data that has a mip_era value equal to 'CMIP6Plus'. (The mip_era metadata value appears both in each file's global attributes as well as its metadata on ESGF.)

If you have any feedback, please add it to the relevant GitHub discussion.

CMIP7 AR7 fast track#

No data available for this phase yet.

This data will be for the CMIP7 AR7 fast track. All data sets for use in the fast track will be published with a mip_era metadata value of 'CMIP7'. This metadata value will appear both in the file's global metadata as well as its metadata on ESGF.

Further details will follow in early 2025.

CMIP7#

No data available for this phase yet.

This data will be for CMIP7. All data sets for use in CMIP7 will be published with a mip_era metadata value of 'CMIP7'. This metadata value will appear both in the file's global metadata as well as its metadata on ESGF.

Further details will follow after the fast track is underway (including details about how updates to this data will be handled over the lifetime of CMIP7).

Recommendation for pre-industrial control#

There are dedicated pre-industrial control files for aerosol optical properties. For aerosol optical properties, these are provided as climatologies and hence have monC in their name (they also have a time axis with only twelve points, so they're hard to miss). There is no recommendation for teams who want to run pre-industrial control with volcanic emissions as yet, that is still being developed in collaboration with early testing teams who are interested in this application.

For full details, see the external documentation.

Grids and frequencies provided#

The volcanic emissions are provided with daily resolution alongside latitude, longitude and injection height information.

The aerosol optical properties are provided with monthly resolution on a latitudinal grid.

Variables provided#

For the aerosol optical properties dataset, the extinction, single scattering albedo, scattering asymmetry factor, effective radius, surface area density and volume density are provided. For emissions, the volcanic SO2 injection time, latitude, longitude, height, depth and mass are provided. Further details are provided in the external documentation (section III and IV).

Uncertainty#

There is considerable uncertainty in the magnitude and height of volcanic SO2 injection for the satellite era. These uncertainties are even larger in the pre-satellite era, for which there is considerable uncertainty on the occurence, timing and location of volcanic SO2 injections. These uncertainties propagate to our aerosol optical properties dataset for the pre-satellite era. Uncertainties are currently not reported in the dataset but they will be in the future.

Differences from CMIP6 or other previous versions#

File formats and naming#

The file formats are quite different from CMIP6 because the data is coming from a different provider. The naming may also be different. Overall, we would say that the data is more uniform now and in line with other input4MIPs data and conventions.

Data#

For a full dive into the changes from CMIP6, see the external documentation.

Revision history#

UOEXETER-CMIP-1-1-3#

v1.2.0 includes climatology data (for piControl simulations) and updates the handling of small eruptions.Hence v1.1.3 is retracted.