Measurements of C2-C5 Hydrocarbons Over the North Atlantic

Latitudinal distributions of ethane, propane, propene, and acetylene in air over the Atlantic from 48°N to 4°S are reported. In addition, measurements of saturated and unsaturated hydrocarbons (C2-C5) at low latitudes and from 55°N to 80°N are presented. The mixing ratios of ethane, propane, and acetylene were found to vary systematically between a few tenths of a ppb and a few ppb. The alkene and higher alkane (C4 and C5) mixing ratios were found to be in the ppt range. The data are discussed with respect to the source distributions and atmospheric lifetimes of the different hydrocarbons.