Photochemistry of OIO: Laboratory study and atmospheric implications

Iodine chemistry influences the oxidizing capacity of the atmosphere, principally by depleting ozone, and induces the formation of new particles in the marine boundary layer. The photochemistry of iodine dioxide (OIO) plays a key role in both these processes. Here we report that OIO photolyses in the visible (480–650 nm), yielding iodine atoms with a quantum efficiency of unity (1.07 ± 0.15). As a result, much smaller sources of iodine precursors are required to cause significant ozone depletion, which has important implications for the marine boundary layer ozone budget.