Temperatures and CH4 mixing ratios near the homopause of the 8 µm north polar hot spot of Jupiter

We have derived homopause temperatures of 180-250 K for the 8-µm north-polar hot spot (8NPHS) of Jupiter by fitting CH4 emission models to 3 and 8 µm spectra of the 8NPHS obtained 24 days apart in 2013. From the fits, we find that CH4 mixing ratios at the 8NPHS are consistent with those reported by Kim et al. (2014) in equatorial regions. We propose possible mechanisms to account for the temperature of the 8NPHS homopause, which is relatively cool compared with the temperatures of other auroral regions, including locally-fixed and transient but energetic auroral particle precipitation.