Top:False color images representing measurements
of total column ozone for October 1990, 91, 92, and 93. The colors
represent concentrations, from black (low) to white (high). The
ozone "hole" is the region of low ozone concentration over Antarctica,
and has been appearing annually since the "early" 1980s. The
average ozone concentration in 1993 represents the lowest amount
Bottom:Total column ozone measurements for the
Southern Hemisphere on 28 October 1993.