Ozone Completion Timeline

  • The Ozone was discovered in Germany

  • As early as 1912, Antarctic explorers recorded observations of unusual veil-type clouds in the polar stratosphere, although they could not have known at the time how significant those clouds would become.

  • NASA has been monitoring the status of the ozone layer through satellite observations since the 1970s, beginning with the TOMS sensors on the Nimbus satellites.

  • scientists began to be concerned about damage to this protective layer caused by atmospheric pollution.

  • The value of 220 Dobson Units is chosen since total ozone values of less than 220 Dobson Units were not found in the historic observations over Antarctica prior to 1979.

    The value of 220 Dobson Units is chosen since total ozone values of less than 220 Dobson Units were not found in the historic observations over Antarctica prior to 1979.
  • The British Antarctic Survey's first documentation of the Antarctic ozone hole in 1985 and subsequent NSF-funded study of the phenomenon alerted the world to the danger of chlorofluorocarbons, or CFCs.

    The British Antarctic Survey's first documentation of the Antarctic ozone hole in 1985 and subsequent NSF-funded study of the phenomenon alerted the world to the danger of chlorofluorocarbons, or CFCs.
  • British scientists produced the first direct evidence that this was actually happening. Antarctic atmospheric data going back to 1957 showed an alarming decline in ozone values over Antarctica each spring - effectively a hole in the ozone layer.

  • In 1986, NASA scientists used satellite data from the Total Ozone Mapping Spectrometer (TOMS) and the Solar Backscatter Ultraviolet (SBUV) instrument to demonstrate that the ozone hole is a regional-scale Antarctic phenomenon.

  • In the northern polar regions, ozone levels in the early 1990s measured ten percent lower than those estimated in the late 1970s.

    In the northern polar regions, ozone levels in the early 1990s measured ten percent lower than those estimated in the late 1970s.
  • 1999 National Medal of Science winner, Susan Solomon, conducted observations that have significantly advanced our understanding of the global ozone layer and changed the direction of ozone research.

    1999 National Medal of Science winner, Susan Solomon, conducted observations that have significantly advanced our understanding of the global ozone layer and changed the direction of ozone research.
  • The largest Ozone hole September 24, 2006.

    The largest Ozone hole September 24, 2006.
  • The 2010 hole was slightly smaller than North America, which is 25 million square kilometers.