Atmospheric tracers during the 2003-2004 stratospheric warming event and impact of ozone intrusions in the troposphere

The restricted wave activities led to a reduced extratropical downward ozone flux from the lower stratosphere to the lowermost stratosphere (or from the "overworld" into the "middleworld"), especially over East Asia. Consequently, during wintertime (15 December~15 February), the total downward ozone transport on 100 hPa surface by the descending branches of Brewer-Dobson circulation over this region was about 10% lower during the 2003-2004 event.

Meanwhile, the extratropical total cross-tropopause ozone flux (CTOF) was also reduced by ~25%. Compared to the cold 1999-2000 winter, the vertical CTOF in high latitudes (60°~90° N) increased more than 10 times during the two warming winters, while the vertical CTOF in mid-latitudes (30°~60° N) decreased by 20~40%. Moreover, during the two warming winters, the meridional CTOF caused by the isentropic transport associating with the enhanced wave activity also increased and played an important role in the total extratropical CTOF budget.