A study of the Arctic NOy budget above Eureka, Canada

These have been compared with data from three models, namely the Canadian Middle Atmosphere Model Data Assimilation System (CMAM-DAS), the Global Environmental Multiscale stratospheric model with the online Belgium Atmospheric CHemistry package (GEM-BACH), and the off-line 3D chemical transport model SLIMCAT to assess the total reactive nitrogen, NOy, budget above Eureka, Nunavut (80.05°N, 86.42°W).

The FTIR data have been also compared with satellite measurements by the Atmospheric Chemistry Experiment-Fourier Transform Spectrometer (ACE-FTS). The FTIR is able to measure four of the five primary species that form NOy: NO, NO₂, HNO₃, and ClONO₂, while the fifth, N₂O₠, was obtained using the N₂O₠/(NO + NO₂) ratio derived from the models and ACE-FTS. Combining these results, a four-year time series of NOy 15-40 km partial columns was calculated.