HDO and SO2 Thermal Mapping on Venus: Short-Term Variations, Statistical Analysis of the SO2 Plumes and Comparison with Spacecraft Data

International audienceWe have continued our ground-based campaign to monitor HDO and SO2 on Venus in the thermal infrared range, using the TEXES (Texas Echelon Cross Echelle Spectrograph) imaging spectrometer at the IRTF (InfraRed Telescope Facility), at Mauna Kea Observatory. Following the observations described in Encrenaz et al. (A&A, 595, A74, 2016), maps of HDO and SO2 have been recorded on December 16, 22 & 23, 2016 (evening terminator), January 20 & 21, 2017 (evening terminator), and July 12 & 13, 2017 (morning terminator). In addition, 9 consecutive observing sessions have been obtained between January 13 and January 21, 2016 (morning terminator). These data will be discussed and compared with our previous measurements. With the whole TEXES data set between January 2012 and July 2017, we are able to study the SO2 short-term variations, which will be presented along with a statistical analysis of the behavior of SO2 plumes as a function of latitude, longitude and local time. We will compare our results with the results obtained by Venus Express and Akatsuki