Nitrogen–ammonia quenching (${\mathrm{N}}_2\rightleftharpoons {\mathrm{NH}}_3$ quenching)

Nitrogen–ammonia quenching occurs when transport preserves a nonequilibrium partition between molecular nitrogen and Ammonia. Their net conversion may be writtenbut its actual relaxation time depends on a multistep reaction network. Near a chemical quench level, that time exceeds the eddy mixing time, so the abundance can retain a deeper value instead of following local thermochemical equilibrium.

Coupled diffusion and chemistry models illustrate ammonia enhancement by transport and destruction at high altitudes by atmospheric photochemistry.^[ref] Interpreting an ammonia feature therefore requires an atmospheric pressure-temperature profile and a transport model, not only a molecular identification.