Record Arctic ozone loss in spring 2011 compared with Antarctic ozone hole conditions
The Arctic winter 2010/2011 was characterized by an unusually stable and cold polar vortex in the lower stratosphere. Meteorological data shows that conditions for the formation of polar stratospheric clouds, and hence the activation of chlorine from reservoir species through heterogeneous processes, were widespread. Values of Vpsc, a temperature based parameter that characterizes the winter average extent of such conditions were in the range of the extreme values reached in the coldest winters on record, i.e., 2000 and 2005. However, in contrast to these previous winters, when the ozone loss period was ended by major stratospheric warmings in March, in 2011 the very stable polar vortex stayed intact and cold well into April. The combination of extremely cold conditions throughout the winter with a long lived and stable vortex in spring led to record chemical destruction of ozone in the Arctic. Based on the measurements of the Match ozonesonde network and the Microwave Limb Sounder (MLS) instrument on Aura we will discuss the degree and the time evolution of this record loss and compare the Arctic ozone loss in 2011 with the range of ozone losses that occurred in early and recent Antarctic ozone holes.