Mars atmosphere during the Mariner 9 extended mission: Television results

Data from the Mariner 9 extended mission provide a record of seasonally varying processes from mid-spring to early summer in the Northern Hemisphere of Mars. Atmospheric phenomena observed by the television cameras during this period are: (1) A faint shelf of brightness near 20 km in height; (2) condensate clouds over Hellas in the early morning, (3) wave clouds over the south polar region indicating strong west to east winds; (4) faint wave clouds over the north polar cap indicating northeast to southwest flow off the cap; and (5) clouds over the major vocanos and Tithonius Lacus which show remarkable repeatability, strong topographic control, and, in some cases, evidence for convective structure.