The French AirCore program
The AirCore is an atmospheric sampler flying under a meteorological balloon. It allows the measurement of the vertical profiles (from the surface up to 30 km of altitude) of atmospheric concentration of greenhouse gases (CO2, CH4 and CO).
Its concept, initially proposed by NOAA, is extremely simple: it consists of a long tube of stainless steel placed under a meteorological balloon which, in the ascending phase, empties its air by its open end, to fill with air during its downward phase. The captured air column is then interpreted in terms of the vertical gas concentration profile using a Picarro type laser diode analyzer.
This system makes it possible to access altitudes not attainable by aircraft flights and to obtain very good vertical resolution. Since 2013, the LMD (CNRS / Ecole Polytechnique / ENS Paris / Sorbonne University) has developed several versions of this instrument and has deployed them, in partnership with CNES (the French Space Agency), LSCE (CNRS / CEA / University of Versailles-Saint-Quentin-en -Yvelines), GSMA (CNRS / Université de Reims) and OPGC (CNRS, Blaise Pascal University), in various places of the globe.