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Scientists "Concerned" Ozone layer over Europe dwindling

 -European Space Agency 2 December 1999
PARIS - The ozone layer over Britain, Belgium, the Netherlands and Scandinavia has dwindled to worrying levels nearly as low as those found in the Antarctic, the European Space Agency (ESA) said Thursday. 
Measurements taken in the Netherlands showed local ozone levels were some two-thirds below the norm for this time of year, confirming the abnormally low levels detected over northwest Europe this week, ESA said in a statement. 
The ozone layer, high up in the atmosphere, shields Earth from much of the sun's harmful ultraviolet rays. A gradual thinning due to emissions of damaging man-made chemicals has increased the occurrence of skin cancer and other illnesses related to over-exposure to ultraviolet rays, scientists say. 
The damage to the ozone layer is worst over Antarctica where a hole about twice the size of China and more than two-and-a-half times the scope of Europe has developed. 


TOMS Observes Low Ozone Event in Northern Hemisphere-NASA

A NASA Goddard Space Flight Center satellite has observed the lowest value of ozone ever seen in the Northern Hemisphere since satellites first began ozone measurements in 1978. The measurement was obtained on November 30, 1999 using the Total Ozone Mapping Spectrometer (TOMS) instrument aboard NASA's Earth Probe (TOMS-EP) satellite.

"This is an extremely low measurement of ozone for the Northern Hemisphere," said Dr. Richard McPeters, Principal Investigator for Earth Probe TOMS

The measurement showed 165 Dobson Units (DU) over the North Sea between Scotland and Norway on November 30, 1999.

The previous low value of 167 DU was observed in the same region on October 30, 1985. The lowest values of ozone in the Northern Hemisphere are typically seen in the late fall period. However, these low northern values rarely drop below 180 DU.

"A combination of stratospheric and tropospheric weather systems can occasionally create these extreme low ozone events," said Dr. Paul A. Newman of the NASA Goddard Space Flight Center. "We understand that dynamics can cause these low ozone events, but we're unsure why this event set a new record low value."

November 30, 1999

TOMS Satellite

December 2, 1999


The NASA images also indicate that the ozone event was also forming along the Eastern Seaboard over the United States and Canada on November 26,1999 but moved towards Europe over the next few days. The ozone levels also dropped over the Western United States as observed from these images.

Images from Earth Probe TOMS Satellite

(Total Ozone Mapping Spectrometer)


Nov 26, 1999


Nov 26,1999 Ozone Hole formation enlarged view


NASA TOMS images 


The NASA TOMS images show that the ozone hole started forming over The United States and Canada as early as November 21, 1999. 



The Canadian Environment  images from Nov 20- Dec 2,1999 indicate that the ozone hole was also forming along the Eastern Seaboard over the United States and Canada . The ozone levels also dropped over the Western United States as observed from these images. The total ozone maps for the northern hemisphere are based on near-real time NASA Earth Probe Total Ozone Mapping Spectrometer (TOMS) gridded satellite data available from the NASA TOMS home page and on ground-based measurements  provided by Environment Canada and  by the Russian Central Aerological Observatory. If available, other ground-based total ozone observations are also used.