Ozone hole bigger and bigger

[MonteSano]

This image, provided by Nasa, captures this year’s ozone hole over Antarctica, which has been declared by scientists in the US as the biggest and deepest on record.

"From September 21 to 30, the average area of the ozone hole was the largest ever observed, at 10.6 million square miles (27.4 square kilometres)," said Paul Newman, of Nasa’s Goddard Space Flight Centre outside Washington.

The ozone layer, a form of oxygen in the upper atmosphere which shields Earth from the sun’s harmful ultraviolet rays, thins out over the South Pole each year. This is largely due to human-made compounds releaing chlorine and bromine gases into the stratosphere, eating into the barrier and causing the hole.


http://www.timesonline.co.uk/article/0,,3-2414002,00.html

[hatrack]

1. Thinner and thinner, too - in fact, it hit 1.2 Dobsons in one largish area

EDIT

The Ozone Monitoring Instrument on NASA's Aura satellite measures the total amount of ozone from the ground to the upper atmosphere over the entire Antarctic continent. This instrument observed a low value of 85 Dobson Units (DU) on Oct. 8, in a region over the East Antarctic ice sheet. Dobson Units are a measure of ozone amounts above a fixed point in the atmosphere. The Ozone Monitoring Instrument was developed by the Netherlands' Agency for Aerospace Programs, Delft, The Netherlands, and the Finnish Meteorological Institute, Helsinki, Finland.

Scientists from NOAA's Earth System Research Laboratory in Boulder, Colo., use balloon-borne instruments to measure ozone directly over the South Pole. By Oct. 9, the total column ozone had plunged to 93 DU from approximately 300 DU in mid-July. More importantly, nearly all of the ozone in the layer between eight and 13 miles above the Earth's surface had been destroyed. In this critical layer, the instrument measured a record low of only 1.2 DU., having rapidly plunged from an average non-hole reading of 125 DU in July and August.

"These numbers mean the ozone is virtually gone in this layer of the atmosphere," said David Hofmann, director of the Global Monitoring Division at the NOAA Earth System Research Laboratory. (emphasis added) "The depleted layer has an unusual vertical extent this year, so it appears that the 2006 ozone hole will go down as a record-setter."

EDIT

http://www.terradaily.com/reports/NASA_And_NOAA_Announce_Ozone_Hole_Is_A_Double_Record_Breaker_999.html