Fig. 2.

ACCESS aircraft campaign data for A NO, B SO₂ and C CO showing vertical profiles from different flights. Very high enhancements in emissions can be seen at low altitudes due to sampling of pollutant plumes in the vicinity of oil/gas facilities (e.g. Heidrun, Norne, Asgard C, Rangrid) and shipping (Deliziosa, Wilson Nanjing). Aged boreal fire plumes from Siberia were sampled at higher altitudes with enhanced CO concentrations as well as one plume at lower altitudes from the metal smelting region in north-west Russia (Kola). From Roiger et al. (2015). ©American Meteorological Society. Used with permission