School of Earth and Environment

Sarah Shallcross Sarah Shallcross

Postgraduate Researcher

Email address:
Room: 10.126

Affiliation: Institute for Climate and Atmospheric Science

Project details

Project title

Combining sophisticated composition-climate models with space-borne, ground-based and in situ measurements to give new estimates of the climate forcing from major historical volcanic eruptions.


Dr Graham Mann, Dr Anja Schmidt, and Dr Ryan Neely


ECMWF - CAMS43 Project

Start date

1 April 2016

Project outline

Volcanic eruptions have the potential to inject huge quantities of sulphur dioxide into the stratosphere. Chemical reactions in the atmosphere convert sulphur dioxide into highly-scattering sulphuric acid aerosols. The scattering effects of these aerosols causes short wave radiation to be scattered back to space, away from the surface, creating a cooling effect. Following large volcanic eruptions this cooling effect has been particularly prominent, such as "the year without summer" caused following the 1815 Mount Tambora eruption.

The last great eruption was the Pinatubo eruption in 1991, which, due to limited observations at the time has varying values for radiative perturbation. This is where models have been used, to try and recreate what observations are available and, in turn, understand the processes occurring at the time of these eruptions to gain a better understanding of their radiative forcing.

This project focuses on using the UM-UKCA model in conjunction with lidar observations available at the time of the Pinatubo eruption to work on the issue of transport to the Southern hemisphere. The model does not appear to pick up the signal of Southern hemisphere transport as strongly as observations seem to show happened.

My first aim, therefore, is:

- To test the model under different conditions to try and better represent this Southern hemisphere transport.

I will be assessing the roles of:

- Meteorology

- Ash

- Stratospheric transport

In order to see if one or a combination of these has a greater or lesser effect on the transport to the Southern hemisphere of the Pinatubo plume.