IGAC ECR Conference 2023

The IGAC ECR conference is held virtually on Gathertown.

I attended virtually, presenting a poster which can be downloaded here.

The work describes how atmospheric oxidants such as ozone and hydroxyl radicals affect sulfate aerosol formation.

In a nutshell

Sulfate aerosols play a significant role in shaping the climate by inducing cooling by directly reflecting sunlight and also by modifying cloud properties. Sulfur dioxide (SO2) is an important sulfate aerosol precursor with the largest sources coming from anthropogenic activity. The oxidants that SO2 react with are controlled by complex chemical processes. In this work, we analysed the output from the UK’s Earth System Model1 from oxidation processes to radiative effect to tease out the effects of oxidants on aerosol and climate.

We show how ➊ OH, O3 and H2O2, which are the main SO2 oxidants response to O3 precursors and CH4 increases. ➋ SO2 oxidation follows SO2 emissions but is perturbed by oxidant changes. SO2 + OH is the dominant oxidizing process and is also the most sensitive to OH changes. ➌ Historical changes in aerosol size distribution is affected by oxidant changes. ➍ Ultimately, historical changes in O3 precursors affect the aerosol abundance in the nucleation mode and have a cooling effect through scattering but CH4 has a warming effect by reducing aerosol cloud interaction.