OZONE/Nimbus-7 Total Ozone Mapping Spectrometer

Tracking damage to the Ozone layer from 1978 to 1993.

“The images on the front of this poster show the measured total ozone over the Earth for each month from November 1978 to April, 1993. The measurements were taken by NASA’s Total Ozone Mapping Spectrometer (TOMS) aboard the Nimbus-7 satellite. The color scale at the bottom shows the amount (sum of all the ozone in a vertical column through the atmosphere) in Dobson units. Normal to high ozone levels are indicated by the colors green, yellow, and red, respectively. Blue and purple indicate low to very low ozone concentrations.

The individual images have been rotated each month in order to show the polar region in the Spring of each hemisphere. This is the season when the most drastic ozone depletion occurs.” [Text, verso]

This stark visualization of the Earth’s Ozone levels over a 15-year period was issued in 1993 by NASA’s Central Operation of Resources for Educators (CORE). It highlights the rapid reduction in Ozone levels across both poles, with evident curtailment in the dispersion of red (high concentration) and an increase in blue and purple areas (very low concentrations).

Fortunately, remediation efforts supported by educational material such as this have made drastic improvements. According to the United Nations Environmental Program, “If current policies remain in place, the ozone layer is expected to recover to 1980 values (before the appearance of the ozone hole) by around 2066 over the Antarctic, by 2045 over the Arctic and by 2040 for the rest of the world.”

Source: UNEP;