Environment Canada

The total ozone maps are based on ground-based measurements available from the World Ozone and Ultraviolet Radiation Data Centre. Preliminary near real-time data from ground-based observations were also used for the most recent maps. Total ozone values are given in Dobson Units. The numbers represent observations taken from ground stations situated at the bottom left corner of the number.

Maps of deviations represent total ozone deviations from the 1978-1988 level estimated using Total Ozone Mapping Spectrometer (TOMS) data for all areas except the Antarctic and from the pre-1980 level estimated using Dobson data over the Antarctic.

Over areas with poor data coverage adjustments are made according to TOMS on Nimbus-7, Meteor-3, ADEOS and Earth Probe satellites. Over the polar night area Dobson and Brewer moon observations and/or NOAA's TIROS Operational Vertical Sounder (TOVS) satellite data are used. TOVS data are also used when the more reliable TOMS data are not available. The mapping algorithm is similar to those used by the WMO Ozone Mapping Centre.

• July 2010 Ozone Hole Images

• August 2010 Ozone Hole Images

• September 2010 Ozone Hole Images

• October 2010 Ozone Hole Images

• November 2010 Ozone Hole Images

• Ozone Hole History

  • Ozone Hole Area Plots 1979-2007

  • Ozone Hole 1980-85

  • Ozone Hole 1986-90

  • Ozone Hole 1991-95

  • Ozone Hole 1996-2000

  • Ozone Hole 2000

  • Ozone Hole 2001

  • Ozone Hole 2002

  • Ozone Hole 2003

  • Ozone Hole 2004

  • Ozone Hole 2005

  • Ozone Hole 2006

  • OzoneHole 2007

  • Ozone Hole 2008

  • Ozone Hole 2009