ISOTOPIC ENRICHMENT OF HEAVY OZONE IN THE STRATOSPHERE

A mass-independent, 3% enrichment of heavy ozone isotopes in the strat osphere can be assigned to a mechanism in which (1) short-wavelength p hotodissociation of ozone produces O-2(v greater than or equal to 26) + O, (2) the O-2)(v greater than or equal to 26) reacts with ground st ate O-2 to produce O-3 + O, and (3) each O atom recombines with O-2 to form O-3. The overall reaction scheme, O-3 + hv + 3O(2) --> 3O(3), pr oduces more ozone than it consumes. The dissociation channel which beg ins this scheme is more probable for heavy ozone than for O-48(3), and one of the oxygen atoms in the original O-3 is incorporated into a ne w O-3. Thus this new ozone source tends to ''distill'' heavy oxygen at oms into the O-3 pool while depleting them from the O-2 pool. The amou nt of enrichment produced by this mechanism, while significant, is sti ll too small to account for the large observed stratospheric enrichmen t of heavy ozone.