October
20,2000-
The Ozone hole  has been reaching
land and population areas in Argentina, Chile and The Falkland Islands all but
two days since October 6,2000(October 9 & 10). 
Ozone
levels are down as much as 70% in some areas. The protective level of ozone has
dropped below  150 dobson units in some areas. It has reached further north
reaching the towns of Rio Gallegos, Puerto Santa Cruz, and Rio Grande affecting
an additional 200,000 people.


Central Intelligence Agency Maps from University of Texas Map Center

October
17,2000-
The Ozone hole  has been reaching
land and population areas in Argentina, Chile and The Falkland Islands all but
two days since October 6,2000(October 9 & 10). 
Ozone
levels are down as much as 45% in some areas. The protective level of ozone has
dropped below  200 dobson units in some areas. The area and population
affected including the Argentinean city of Ushaia which has a population of
30,000 and Punta Arenas, Chile which has a population of 120,000 are all at risk
during this time period. The public should avoid going outside during the peak
hours of 11:00 a.m. and 3:00 p.m. to avoid exposure to the UV rays. If people do
go outside during these hours they should wear protective sunscreen and if
possible a hat or head covering and sunglasses with a uv rating.


For the Second time in less than a week 


Dangerous levels of  UV rays bombard Chile and Argentina


October 12,2000
The Ozone hole  again
reached land and population areas in Argentina, Chile and The Falkland Islands
on October 11, 2000. 
Ozone
levels are down as much as 40% in some areas. The protective level of ozone has
dropped below  200 dobson units in some areas. The area and population
affected including the Argentinean city of Ushaia which has a population of
30,000 and Punta Arenas, Chile which has a population of 120,000 are all at risk
during this time period. The area will be under these conditions for the next
24-30 hours. The public should avoid going outside during the peak hours of
11:00 a.m. and 3:00 p.m. to avoid exposure to the UV rays. If people do go
outside during these hours they should wear protective sunscreen and if possible
a hat or head covering and sunglasses with a uv rating.


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


Ozone Hole reaches South America again-


Dangerous levels of  UV rays bombard Chile and Argentina Humans, animals
and plant life
all at
risk of exposure


October 7,2000-
The Ozone hole has again reached
land and population areas in Argentina, Chile and The Falkland Islands. 
Ozone
levels are down as much as 40% in some areas. The protective level of ozone has
dropped below under 200 dobson units in some areas. The area and population
affected including the Argentinean city of Ushaia which has a population of
30,000 and Punta Arenas, Chile which has a population of 120,000 are all at risk
during this time period. The area will be under these conditions for the next
30-40 hours.


In Argentina the regional Secretary of Health is planning on implementing a
system that will give warnings of ozone levels and ultraviolet levels to the
population. The system will be similar to traffic signals.


The public should avoid going outside during the peak hours of 11:00 a.m. and
3:00 p.m. to avoid exposure to the UV rays. If people do go outside during these
hours they should wear protective sunscreen and if possible a hat or head
covering and sunglasses with a uv rating.


The ozone layer in the upper atmosphere is the key filter for damaging
ultraviolet-B (UV-B) radiation in the Sun’s rays. Without it, organisms suffer
extensive DNA damage, which in humans results in a greater increase in the risk
of skin cancer, eye cataracts and defects in the body’s immune system.


1 Dobson Unit (DU) is defined to be 0.01 mm thickness at STP (standard
temperature and pressure). Ozone layer thickness is expressed in terms of Dobson
units, which measure what its physical thickness would be if compressed in the
Earth’s atmosphere.

In
those terms, it’s very thin indeed. A normal range is 300
to 500 Dobson units, which translates to an eighth of an inch-basically two
stacked pennies.

In space, it’s best not to envision the ozone
layer as a distinct, measurable band. Instead, think of it in terms of parts per
million concentrations in the stratosphere (the layer six to 30 miles above the
Earth’s surface).


The unit is named after G.M.B. Dobson, one of the first scientists to
investigate atmospheric ozone . He designed the ‘Dobson ozone spectrophotometer’
– the standard instrument used to measure ozone from the ground. The Dobson
spectrometer measures the intensity of solar UV radiation. A single measurement
uses two wavelengths of uv, but for normal operation pairs of readings are taken
at two different wavelength settings for a total of four wavelengths, two of
which are absorbed by ozone and two of which are not.


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