NH3 and PH3 photochemistry in the Jovian atmosphere

Essential elements of the coupled NH3-PH3 photochemistry in the stratosphere of Jupiter are modeled. It is shown that the presence of PH3 in the Jovian stratosphere will inhibit the photochemical destruction of NH3 and that, conversely, the presence of NH3 will accelerate the photochemical removal of PH3. For reference purposes, NH3 and PH3 density profiles for a model atmosphere having a temperature of 120 K and an eddy diffusion coefficient of 20,000 sq cm/s are calculated in the case of zero rate constants for the reactions where H + PH3 yields PH2 + H2 and NH2 + PH3 yields NH3 + PH2.