Unusually low ozone, HCl, and HNO₃ column measurements at Eureka, Canada during winter/spring 2011

In winter 2011, the polar vortex was strong and cold for an unusually long time. Our research site, located at Eureka, Nunavut, Canada (80.05° N, 86.42° W), was mostly inside the vortex from October 2010 until late March 2011.

The Bruker 125HR Fourier transform infrared spectrometer installed at the Polar Environment Atmospheric Research Laboratory at Eureka acquired measurements from 23 February to 6 April during the 2011 Canadian Arctic Atmospheric Chemistry Experiment Validation Campaign. These measurements showed unusually low ozone, HCl, and HNO₃ total columns compared to the previous 14 yr. To remove dynamical effects, we normalized these total columns by the HF total column.