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 [CH3C(O)OONO2> are ubiquitous components of the troposphere and the lower stratosphere. Average acetaldehyde concentrations (from ethane oxidation) of 22 parts per trillion (ppt), 3 ppt, and 7 ppt; average acetone concentrations (from propane oxidation) of 111 ppt, 15 ppt, and 3 ppt and average PAN concentrations of 17 to 34 ppt, 90 to 360 ppt, and 40 to 85 ppt are estimated for lower troposphere (~2 km), upper trposphere (~9 km), and the lower stratosphere (~ 15 km), respectively. These calculations suggest that in the troposphere, nitrogen oxides (NQx) 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 ? CH3C(O)OO+NO2> with inorganic NO2 and acts as reservoir of inorganic NOx. Measurement methods for PAN are currenlty available to verify these predicted results.