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Environment Canada
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ARQX FTP Site

Ozone maps and graphs are also available from the
ARQX FTP site: maps or graphs.

Maps of Total Ozone and Ozone Deviations

File name is toyyyymmdd.gif or deyyyymmdd.gif, where

to means Total Ozone for the day,
de means Deviation from normal for the day,
yyyy is the year,
mm is the month (01 to 12),
dd is the day (01 to 31)

The numbers represent observations taken from ground stations situated at the bottom left corner of the number. Over areas with poor data coverage adjustments are made according to TOMS on Earth Probe and TOVS on NOAA satellites. Total ozone values are in Dobson Units, deviations are in percent.


Total Ozone Time Series

The file name indicates the network stations. Station location information is available from the Canadian ozone page. If the subdirectory is a year, the graphs show ozone for the whole year. If the subdirectory is “current”, the graphs show ozone for this year up to yesterday.

The graphs show daily mean total ozone values (in Dobson Units) as a function of the season over Canadian stations for the current year up to yesterday. The results of most accurate Brewer direct sun measurements are shown in red, all other types of data are shown in blue. The green line indicates total ozone values smoothed by one month running mean. The dashed lines represent “normal”, pre-1980 total ozone annual cycle and two standard deviations envelope for daily mean total ozone. The actual data are available (typically, with one month delay) from the The World Ozone and Ultraviolet Radiation Data Centre (WOUDC).


UV Index Plots

The file name indicates the network stations. Station location information is available from the Canadian ozone page. If the subdirectory is a year, the graphs show UV indices for the whole year. If the subdirectory is “current”, the graphs show UV indices for this year up to yesterday.

The plots show the measured by Brewer spectrophotometers UV index values as a function of the season and the time of the day over Canadian stations for the current year up to yesterday. The time is shown as a solar time, i.e. the sun is in its highest position over the horizon exactly at noon. The gray areas indicate periods with no observations. The actual spectral UV data are available (with some delay) from the World Ozone and Ultraviolet Radiation Data Centre (WOUDC).


Daily Maximum UV Index Plots

The file name indicates the network stations. Station location information is available from the Canadian ozone page. If the subdirectory is a year, the graphs show UV indices for the whole year. If the subdirectory is “current”, the graphs show UV indices for this year up to yesterday.

The daily maximum UV index plots are based on ground-based measurements by Brewer spectrophotometers The actual measurements are indicated by the red dots. ozone values are shown by the blue line. Estimates of UV Index for clear sky no-snow conditions and each day's total ozone values are shown by the magenta line.


Today's UV Index Plots

The file name indicates the network stations. Station location information is available from the Canadian ozone page. The UV index plots are based on ground-based measurements by Brewer spectrophotometers carried out by the Science and Technology Branch. The actual measurements are indicated by red dots and the red line. Estimates of UV Index for clear sky no-snow conditions and “normal” pre-1980 total ozone values are shown by the blue line. Estimates of UV Index for clear sky no-snow conditions and today's total ozone values are shown by the magenta line. If today's total ozone is normal the magenta line will cover the blue line. The time is shown as both local time (in a time zone) and solar time (the sun is in its highest position over the horizon exactly at noon). The plots are updated every five minutes. It is necessary to click on "Refesh" to see the updates.