Thursday, October 15, 2015, 4:00PM - 5:00PM
RL-1 room 269
Arctic firn studies have indicated that nonmethane hydrocarbons (NMHC) mixing ratios increased significantly starting in about 1950, peaked in the 1970s or 1980s (depending on the specific compound), and have steadily declined since then. Ten years of analysis in NMHC in NOAA's World Meteorological Organization Global Atmosphere Watch (WMO/CAW) program network flasks has made it possible to investigate an apparent reversal in ethane and propane mixing ratio trends. Ethane and propane trends at network flask sites indicate this reversal may be related to increased oil and gas exploration activities. This link is evidenced by particularly strong, increasing ethane and propane mixing ratio trends downwind of significant oil and gas development in the Northern Hemisphere.