Carbon monoxide and methane in the North American Arctic and Subarctic troposphere: July–August 1988

摘要: Measurements of carbon monoxide (CO) and methane (CH4) were made in the North American Arctic during July–August 1988. The distribution CH4 was variable atmospheric mixed layer (0–2 km), with concentrations determined primarily by interactions biogenic emissions from wet tundra turbulent mixing processes. Carbon exhibited little variation unpolluted environments indicating a minor role for sources and/or sinks determining its distribution. In free troposphere (2–6 km) both CO variable. Concentration gradients most frequently associated intrusions upper tropospheric or stratospheric air into midtroposphere, forest fires, long-range transport enhanced these gases unidentified sources. Summertime haze layers midtropospheric enhancements similar to those measured winter events. However, summer pollution episodes did not exhibit positive correlations particulate sulfate. subarctic events observed Boundary Layer Expedition (ABLE 3) result fires natural origin. tendency relatively high variability at altitudes 3–6 km indicates that ground-based monitoring will provide an adequate assessment chemical composition support future global change studies.