Middle stratospheric polar vortex ozone budget during the warming Arctic winter, 2002–2003

A "passive ozone" experiment shows that only ~55% of the vertical ozone mass flux in February and March can be attributed to the variation in vertical transport. It is also shown that the enhanced downward ozone above ~32 km should be attributed to the springtime photochemical ozone production. Due to the increase of air temperature, the NO x reaction rate increases by 40%-80% during the SSW events.

As a result, NO x catalytic cycle causes another 44% decrease in polar vortex ozone compared to the net ozone changes due to dynamical transport. It is also shown that the largest change in polar vortex ozone is due to horizontal advection by planetary waves in January 2003.