Herding cats? A multi-model perspective on tropospheric ozone

Abstract:

Various global multi-model studies have investigated tropospheric ozone changes over multi-decadal timescales. Several robust features emerge, which – for instance – allows the IPCC to associate high confidence in the radiative forcing associated with ozone increases between 1750 and the present day. However, such quantities hide the spread in results between different models, particularly when looking at seasonal and regional scales, and including for comparisons with observations. What can we learn about our scientific understanding from the model spread? What can we learn about models from the model spread? And can we make recommendations for deficient or missing processes if we wish to use our models for environmental prediction? Of course, these questions also have to be asked in the context of what we want the model(s) to do (air quality, climate, stratospheric ozone depletion etc.).

This poster will report ongoing work in my group which draws on results from multi-model experiments conducted in support of the most recent IPCC report (CMIP5 and ACCMIP), with an eye to the expected outcomes from the ongoing Chemistry-Climate Model Initiative (CCMI) model simulations.