Combined GOES-EAST and METEOSAT infrared satellite image from 19 November 2001 (18 UTC). The flight track of the Falcon is superimposed (black triangle). The flight started/ended in Oberpfaffenhofen (Germany), and the aircraft made a stopover in Stockholm (Sweden). At the time of the airborne CONTRACE measurements over Scandinavia on 19 November 2001 the next cold front and associated warm conveyor belt pushed polluted air masses from the eastern United States out to the Atlantic (black ellipse). Credit: Journal of Geophysical Research.