Observations of changing Mars contrasts by Viking orbiter television cameras have provided a decription of changing atmospheric opacity in the Southern Hemisphere (paper 1). This report extends those measurements into the Northern Hemisphere over a great time period and provides a detailed description of photometric changes at the lander sites as seen from orbit. Reflectivity changes compared with optical depth increases produced by four dust storms indicate mean particle scattering changes with storm evolution as well as substantial opacity in the Northern Hemisphere for the duration of nearly a Martian year.