We have compared measured abundances of NOy, O3, H2O, CH4, HCl, and N2O from ATMOS and aerosol from SAGE II from inside and outside the Arctic vortex with in situ observations from the SPADE aircraft campaign in April/May 1993. When the distinction between vortex and extra-vortex air is taken into account, SPADE measurements of NOy, O3, H2O, CH4, HCl, and aerosol abundances, correlated with [N2O>, demonstrate excellent agreement with ATMOS and SAGE II data. Observations of low [HCl> and high [ClNO3> inside the vortex by ATMOS and low [HCl> in vortex fragments by ALIAS suggest that vortex-influenced air masses maintained unusually high levels of [ClNO3> throughout spring 1993. ¿ 1999 American Geophysical Union