1977 Global Dust Storm A (Viking Era, First Storm)

The first of two global dust storms observed by the Viking mission in 1977 developed in the southern hemisphere during local summer and expanded planet-wide over several weeks. Viking lander meteorology instruments recorded elevated wind speeds and pressure fluctuations, while Viking orbiter cameras tracked the storm's evolution for the first time from an orbiting platform. This storm, combined with the second 1977 event, provided the first systematic dataset for modelling dust storm initiation and global transport.