Thermospheric/mesospheric temperatures on Venus: Results from ground-based high-resolution spectroscopy of CO2 in 1990/1991 and comparison to results from 2009 and between other techniques

► We measure temperatures in Venus lower thermosphere by infrared spectroscopy. ► Retreived values are warmer in 1990/1991 than 2009. ► Values are consistent with results from other observing techiques. ► We see large variability on all timescales.