Based on the measured atmospheric distributions of ethane and propane (at midlatitudes in the northern hemisphere) and a simplified mechanism for their oxidation, it is predicted that acetaldehyde, acetone, and PAN are ubiquitous components of the troposphere and the lower stratosphere. Average concentrations of acetaldehyde of 22 ppt, 3 ppt, and 7 ppt; acetone of 111 ppt, 15 ppt, and 3 ppt; and PAN concentrations of 17 to 34 ppt, 90 to 360 ppt, and 40 to 85 ppt are estimated for the lower troposphere, upper troposphere, and the lower stratosphere respectively. These calculations suggest that in the troposphere, nitrogen oxides contained in their organic form may be as much or more abundant as their inorganic form. This organic form of reactive nitrogen is in chemical equilibrium (CH3C(O)OONO2 yields CH3C(O)OO + NO2) with inorganic NO2 and acts as reservoir of inorganic NO(x). Measurement methods for PAN are currently available to verify these predicted results.