Io's atmosphere: Constraints on sublimation support from density variations on seasonal timescales using NASA IRTF/TEXES observations from 2001 to 2010

► We have fitted 7 years of Io 19 μm spectra from 2001 to 2010. ► Data shows SO2 atmospheric temperatures are below 150 K, with a mean of 110 ± 18 K. ► Sub-solar SO2 grew from 0.61 ± 0.15 (2004) to 1.51 ± 0.22 (×10−17 cm−2) (2010). ► Good correlation of increasing atm. density with decreasing heliocentric distance. ► Constraints on thermal inertia and albedos of SO2 frost were retrieved.