The stratospheric and mesospheric NOy in the 2002-2004 polar winters as measured by MIPAS/ENVISAT

The Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) on board ENVISAT, provided global (pole-to-pole, the polar night winter regions) measurements of nearly all constituents of the NOy family (including NO, NO2, HNO3 and H2O5) from July 2002 to the end of March 2004 from the upper stratosphere up to the middle mesosphere. The inter-annual variability of the NO2 and HNO 3 abundances in the Arctic and Antarctic winters from September 2002 through March 2004 was enormous with tremendous hemispheric asymmetry and extraordinary values in two winters. The o1rigin of these variations and of the extreme measured values has been analyzed on the basis of the changing atmospheric dynamics (using the CH4 tracer) and solar activity, including the extraordinary solar protons events of Oct-Nov 2003. © Springer Science+Business Media, Inc. 2007.