by Wm. Robert Johnston
last updated 26 December 2002
Description: The light green line indicates monthly measurements from Arosa, Switzerland, while the red line shows a twelve-month moving average for the same data. Measurements from 1925 to 1998 are ground based; measurements from 1999 to 2002 are satellite based (NASA TOMS) and may not be properly calibrated with the earlier data.
Comments: The graph shows the following:
© 2001, 2002 by Wm. Robert Johnston.
Last modified 26 December 2002.
Return to Home. Return to Environmental Topics. Return to Some scientific data on the ozone issue.