From the Surface to the Stratosphere: Enabling In Situ Measurements of Atmospheric Trace Gases for Air Quality and Climate Applications

In situ observations of the atmosphere are critical for understanding specific processes, for evaluating remote sensing retrievals and for driving and evaluating modeling capabilities. NOAA’s Global Monitoring Laboratory (GML) acquires long-term, continuous in situ observational records of atmospheric constituents for monitoring of the atmosphere and for understanding and predicting past and future changes. 
The development of new technologies, methodologies or platforms for making these observations – and transitioning these technologies into operations – is essential for filling spatial and temporal atmospheric sampling gaps and addressing long-standing scientific hypotheses. Here, multiple innovations for enabling atmospheric trace gas observations will be discussed, with a focus on NOAA’s AirCore Program. The AirCore is a patented (circa early 2000’s) balloon-borne air sampling system that has brought about the unique capability of passively capturing a continuous sample of air from the lower stratosphere (~25 km MSL) to the Earth’s surface. Measurements of these samples result in calibrated profiles of long-lived atmospheric trace gases. Over the past decade, several updates to the NOAA AirCore Program have included the development of new analytical systems for expanding the number of species measured in AirCore samples, which helps to examine how the Brewer-Dobson Circulation may be changing with climate. Looking to the future, new platforms for recovery of the AirCore will provide the capability of expanding trace gas vertical profiling efforts in data-poor, but climate critical regions such as the tropics.