Earth System Research Laboratory Halocarbons and Other Atmospheric Trace Gases Radiatively Important Trace Species (RITS) Measurements

The Halocarbons and other Atmospheric Trace Species (HATS) group aims to quantify the atmospheric burden, and the distributions and magnitudes of sources and sinks for nitrous oxide and other halogen containing compounds. They utilize numerous types of platforms, including ground-based stations, towers, ships, aircraft, and balloons to accomplish their mission. HATS measures chlorofluorocarbons (CFCs) at measurement sites spanning the globe. CFCs are non-toxic, non-flammable chemicals that contain carbon, chlorine, and fluorine atoms. CFCs were used as solvents, refrigerants, and aerosol sprays. While inert in the troposphere, they decompose in the stratosphere to release chlorine for destructive reactions with ozone. This process eventually led to the creation of the "Ozone Hole" over the Antarctic. Monitoring the amounts of CFCs and other trace gases is important, both for tracking the growth and recovery of the Ozone Hole, and because many upward trending trace gases are potent and durable greenhouse gases.

Original in-situ sampling electron capture gas chromatographs ("RITS"): The Radiatively Important Trace Species (RITS) program consisted of five stand-alone systems that were used to make in-situ measurements at Barrow, AK (BRW), Mauna Loa, HI (MLO), American Samoa (SMO), South Pole, Antarctica (SPO), and Niwot Ridge, CO (NWR) from 1983 until 2001 when the last of the systems was retired. The RITS systems were replaced by the next-generation CATS systems that have remained operational since then. The RITS systems measured nitrous oxide (N2O), the chlorofluorocarbons CFC-12 (CCl2F2), CFC-11 (CCl3F), and CFC-113 (CCl2F-CClF2, although quality measurements of this gas have been nullified by the lack of stable references during the RITS period), methyl chloroform (CH3CCl3), and carbon tetrachloride (CCl4) once per hour.

Through the Big Earth Data Initiative (BEDI), ESRL/GMD has taken their data collection and converted files into NetCDF-4, a self-describing format.