David Etheridge - firn air sampling

David Etheridge
Dr David Etheridge from CSIRO will measure past atmospheric composition using air sampled from the ice sheet at Aurora Basin.

CSIRO Marine and Atmospheric Research

I will be sampling air from the ice sheet at Aurora Basin. The air will be measured for changes in atmospheric composition, including the levels of greenhouse gases and ozone-depleting gases, before direct atmospheric monitoring began. The results will be used to understand what caused the gases to change and to improve predictions of their influence on climate and atmospheric chemistry in the future.

Air will be extracted directly from the upper 100 metres (the firn layer) and later, in laboratories, from the bubbles in the ice cores. Some of the air will be measured at the site by Jerome Chappellaz, which will help us check the air age as we drill. The air in the firn is expected to go back almost 100 years and several thousand years in the ice.

We will measure a wide range of gases and isotopes at CSIRO, and at the laboratories of our collaborators, and model the enclosure of the air to obtain its age and correct for diffusion. The resulting atmospheric records will be used to constrain models of global biogeochemistry and climate.

Career highlights

My background and PhD are in earth and atmospheric sciences. My current focus is on the science of atmospheric greenhouse gases and the mitigation of their emissions. This will be my eighth field trip to the polar ice caps. I’m looking forward to joining the Aurora Basin team, many of whom I’ve had the pleasure of working with already, on the ice and in the lab.