Average ozone in equatorial and north temperate zones, 1978-2002

by Wm. Robert Johnston
last updated 26 December 2002

Description: The lines show monthly average ozone for these regions:

The measurements are satellite based, from NASA's TOMS.

Comments: There is a trend for greater average amounts of ozone at greater distances from the equator. In all three zones ozone levels vary in a one-year cycle, with the amount of variation greater at greater distances from the equator. It appears that average ozone levels in the midlatitutes reached a minimum around 1994, but there is not an obvious long term trend closer to the equator.

Source: NASA TOMS, on line.


© 2001, 2002 by Wm. Robert Johnston.
Last modified 26 December 2002.
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