Background Information about the Ozone Hole
Every year for the past several decades
the return of sunlight to the high latitudes of the Southern Hemisphere has produced massive
depletion of ozone over Antarctica. Observations
in Antarctica initiated in the 1950's document this progressive loss of ozone during
the Southern Hemisphere spring. Satellite data from the NASA/TOMS showed that the affected
area was not just limited to over the observation stations, but over most of Antarctica.
This area of 50-75% depletion of total ozone has been labeled as the ozone
hole. The ozone hole is defined geographicaly as the area wherein the total ozone
amount is less than 220 Dobson
Units. The ozone hole has steadily grown in size (up to 27 million sq km) and duration
(from August through early December) over the past two decades. This is
graphically illustrated in ozone hole area progression plots
for the years 1980 to present.
Areas of countries and continents are listed in the table
below for reference in comparison to the size of the ozone hole.
NOAA monitors the progression of the ozone hole from
space and on the
ground in Antarctica.
Scientific analysis and discussion of historical ozone holes (1994 - 2009) are available at the
NOAA/CPC Stratospheric Winter Summary site.
Current Status of the Antarctic Ozone Hole
current year's ozone hole plot shows
the progression of this year's ozone hole (red line) and is placed in reference with
last year's ozone hole conditions (blue line) and conditions over the previous
ten years. The maximum ozone hole area (million sq km) for each day over the ten year period is
shown as the upper black line. The minimum ozone hole area for each day of this same period
is shown as the lower black line. The mean ozone hole area for each day over this period
is shown as the green line. The gray shaded area in August depicts the decreasing degree of uncertainty
in the ozone hole size estimate as more of the polar region becomes sunlit.
The figure is updated daily August through December.
Note that data in August is not as reliable as succeeding
months due to limited observation coverage by the ozone monitoring instrument.
Ozone Data Source
Current and past ozone conditions presented here have been
measured by Solar Backscatter UltraViolet(SBUV/2) and
Ozone Mapping and Profiler Suite (OMPS) onboard
a series of NOAA Polar Operational Environmental
Additionally OMPS has been onboard Suomi National
Polar Orbiting Partnership (S-NPP) since 2012.
Check out the
Southern Hemisphere Total Ozone
Analysis from OMPS S-NPP to see the current status of Antarctic ozone.
Comparative Land Sizes
Below is a table of geographic areas to be used as
references in conceptualizing just how large the ozone hole can get.
|Following are referable areas:
||8,923,000 Sq Km
||9,363,130 Sq Km
||10,498,000 Sq Km
||13,340,000 Sq Km
||17,078,000 Sq Km
||25,349,000 Sq Km
||30,335,000 Sq Km
|S. Pole to 70 S
||15,300,000 Sq Km
|S. Pole to 65 S
||23,890,000 Sq Km