Nitric acid measurements at Eureka obtained in winter 2001-2002 using solar and lunar Fourier transform infrared absorption spectroscopy: Comparisons with observations at Thule and Kiruna and with results from three-dimensional models

The measurements were also compared with results from a chemistry-climate model, the Canadian Middle Atmosphere Model (CMAM), and from a three-dimensional chemical transport model, SLIMCAT. This is the first time that CMAM HNO₃ columns have been compared with observations in the Arctic. The comparison of CMAM HNO₃ columns with Eureka and Kiruna data shows good agreement.

The warm 2001-2002 winter with almost no polar stratospheric clouds makes the comparison with this version of CMAM, which has a known warm bias, a good test for CMAM under these conditions. SLIMCAT captures the magnitude of HNO₃ columns at Eureka, and the day-to-day variability, but generally reports higher values than were measured at Thule and Kiruna.