lotus

previous page: 06 Where can I find pictures of the ozone hole on the net?
  
page up: Ozone Depletion: The Antarctic Ozone Hole FAQ
  
next page: 08 When did the hole first appear? (Ozone Depletion: The Antarctic Ozone Hole)

07 How big is the hole, and is it getting bigger? (Ozone Depletion: The Antarctic Ozone Hole)




Description

This article is from the Ozone Depletion: The Antarctic Ozone Hole FAQ, by Robert Parson rparson@spot.colorado.edu with numerous contributions by others.

07 How big is the hole, and is it getting bigger? (Ozone Depletion: The Antarctic Ozone Hole)

During the years 1978-1987 the hole grew, both in depth (total ozone
loss in a column) and in area. This growth was not monotonic but
seemed to oscillate with a two-year period (perhaps connected with the
"quasibiennial oscillation" of the stratospheric winds.) The hole
shrank dramatically in 1988 but in 1989-1991 was as large as in 1987,
and in 1992-95 was larger still. In 1987 and 1989-95 it covered
the entire Antarctic continent and part of the surrounding ocean. The
exact size is determined primarily by meteorological conditions, such
as the strength of the polar vortex in any given year. The boundary is
fairly steep, with decreases of 100-150 DU taking place in 10 degrees
of latitude, but fluctuates from day to day. On occasion, the nominal
boundary of the hole has passed over the tip of S. America, (55
degrees S. Latitude). Australia and New Zealand are far outside the
hole, although they do experience ozone depletion, more than is seen
at comparable latitudes in the Northern hemisphere. After the 1987
hole broke up, December ozone levels over Australia and New Zealand
were 10% below normal. [WMO 1991] [Atkinson et al.] [Roy et al.].

 

Continue to:













TOP
previous page: 06 Where can I find pictures of the ozone hole on the net?
  
page up: Ozone Depletion: The Antarctic Ozone Hole FAQ
  
next page: 08 When did the hole first appear? (Ozone Depletion: The Antarctic Ozone Hole)