Venus mesosphere ALMA observations

Temperature profiles were later used to retrieve SO, SO_2_, and H_2_O. We used H_2_O as a tracer for water assuming a D/H enrichment of 200 times the terrestrial value. We derived 3-D maps of mesospheric temperatures in the altitude range 70-105km.

SO, SO_2_, and H_2_O are characterized by a negligible abundance below ~85km followed by an increase with altitude in the upper mesosphere. Disk-averaged SO abundances present a maximum mixing ratio of 15.0+/-3.1ppb on November 26 followed the next day by a minimum value of 9.9+/-1.2ppb. Due to a very low S/N, SO_2_ could only be derived from the disk-averaged spectrum on the first day of observation revealing an abundance of 16.5+/-4.6ppb.

We found a SO_2_/SO ratio of 1.5+/-0.4. Global maps of SO reveal strong variations both with latitude and local time and from day to day with abundance ranging from <1 to 15ppb. H_2_O disk-averages retrievals reveal a steady decrease from November 14 to 27, with the abundance varying from 3.6+/-0.6ppm on the first day to 2.9+/-0.7ppm on the last day.

H_2_O maps reveal a slightly higher abundance on the evening side compared to the morning side and a strong depletion between the first and the second day of observation.