EMS - Measurements of CFCs and Radiatively Important Trace Species

• Investigators: Diana Barnes, Geoff Dutton, James Elkins, Elaine Gottlieb, Michael McElroy, Steven Wofsy
• Contact: Elaine Gottlieb
• Start date: 1996-01-01
• End date: ongoing
• Location: Prospect Hill Tract (Harvard Forest)
• Latitude: +42.537755
• Longitude: -72.171478
• Elevation: 340 meters
• Taxa:
• Keywords: CFCs, CH3CCl3, CO, H2, industrial pollution, N2O, PCE (C2Cl4), SF6, urban pollution
• Abstract:

  Measurements of 13 ozone-depleting and/or greenhouse gases are taken above the forest canopy at Harvard Forest, downwind of the New York City - Washington, D. C. corridor, every 25 minutes using a four-channel gas chromatographic system called FACTS (Forest and Atmosphere Chromatograph of Trace Species). The species measured are H2, CO, CH4, methyl chloroform (CH3CCl3), chloroform (CHCl3), carbon tetrachloride (CCl4), CFC-11 (CCl3F), CFC-12 (CCl2F2), CFC-113 (C2Cl3F3), halon-1211 (CBrClF2), perchlorethylene (C2Cl4), nitrous oxide (N2O), and sulfur hexafluoride (SF6). Observations began in January 1996 and are continuing.

• Methods:

  FACTS is a fully automated, four-channel gas chromatograph with packed columns and electron capture detectors. Atmospheric measurements alternate with calibration standard measurements every 25 minutes; the air samples are from above the canopy of the forest (29 m).

• Related datasets: HF004