The HATS group’s primary objective is the study of trends and distributions of atmospheric trace gases with a focus on those that influence stratospheric ozone, climate, and air quality.


We and our partners collect air samples in small containers (flasks) and ship them to Boulder for analysis. Using flasks, we are able to collect air samples from surface sites, tall towers, aircraft, and under the Antarctic snow (firn air).

We operate in-situ instruments that perform hourly, automated measurements of select gases at baseline observatories.

We participate in special projects (campaigns) involving aircraft and balloons to study atmospheric composition and transport. For these campaigns, we use specially designed instrument and air collection tools to make measurements in hard-to reach places, such as the lower stratosphere.


We perform the analysis using gas chromatographs with mass selective detection (GC-MS) or electron capture detection (GC-ECD). We measure over 60 gases from sites all over the world.

Informing Society and Policy Makers

These data inform us on the trends and distributions of ozone-depleting gases and related compounds. The production of ozone-depleting gases is regulated by the Montreal Protocol on Substances that Deplete the Ozone Layer. Our data inform scientists and policy makers on the effectiveness of the Montreal Protocol and potential recovery of stratospheric ozone. Because many ozone depleting gases and substitutes are also greenhouse gases, our measurements also provide climate-relevant information, e.g. the amount of heat trapped in the atmosphere by gases such as nitrous oxide, chlorofluorocarbons, and their replacements.