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Uploaded on Tuesday 21 Feb 2012
Methane in Air Above Water Surface
Riccardo Pravettoni, UNEP/GRID-Arendal
Mixing ratio of methane in the air above the water surface measured along a ship’s route in September 2005. The dotted line shows the Latitude-specific monthly average of 1.85 parts per million by volume established for the Barrow, Alaska, USA, monitoring station at 71° 19’ N, 156° 35’ W (http://www. cmdl.noaa.gov/ccgg/insitu.html); this is the normal level of methane in the atmosphere at this latitude.