DOE OSTI2019
The AirCore is a balloon-borne sampler patented and developed at the National Oceanic and Atmospheric Administration (NOAA) Earth System Research Laboratory (ESRL) Global Monitoring Division (GMD) (Tans 2009) that has the capability to provide full-column measurements of greenhouse gases and other trace gas species (Karion et al. 2010). It consists of a long, coated stainless steel tube that is filled with a known trace gas mixture prior to balloon launch (Figure 1). The AirCore is opened at one end prior to balloon launch and, as the balloon ascends, it evacuates to ambient pressure. At 30 km, the balloon is cut away and the AirCore descends via parachute, now capturing an atmospheric air sample or “core” of air from 30 km to the surface due to the pressure gradient between the evacuated AirCore and the environment. Upon landing, the AirCore is closed, preserving the air sample collected in-flight. Because diffusion acts slowly on the AirCore sample in the four hours that it typically takes to launch, retrieve, and analyze the sample, it is possible to capture more than 100 discrete samples in the atmospheric profile collected by the AirCore. Currently, the AirCore is analyzed for carbon dioxide (CO2), methane (CH4), and carbon monoxide (CO) at NOAA/ESRL GMD, but the sample collected can be measured on a variety of other analyzers to obtain full-column profiles of other trace gas species. Unlike routine aircraft measurements, the AirCore provides a low-cost alternative to atmospheric profiling and captures >95% of the atmospheric column. It has a variety of applications, including to full-column greenhouse and trace gas sampling and monitoring, to satellite and remote-sensing instrumentation evaluation, and to tropospheric and stratospheric model evaluation.
Greenhouse gases, Southern Great Plains, balloon-b↗