The hole in the ozone layer over Antarctica stretched for the third time this year to reach cities in the south of Argentina and Chile according to the Izaña Atmospheric research centre in Tenerife, Canary Islands.
The increase of the hole in the ozone layer is particularly harmful in the months of October and November, when ultraviolet radiation increases in the Southern hemisphere.
The ozone layer has diminished more than 50% from its normal values and the UV intensity index has jumped from four to ten, according to the 16 October reading when the hole reached the 51 degrees south of Rio Gallegos in Argentine Patagonia, said Alberto Redondas, a researcher at Izaña.
Redondas added that the area affected by the ozone layer hole, including populated areas of both Argentine and Chilean Patagonia, reached a first peak last 16 September, according to the World Meteorological Organization.
The maximum ozone layer hole over Ushuaia in Tierra del Fuego was recorded in 2006, when it reached an area of 26 million square kilometers. This year the area has reached 24 million square kilometers, after 2011 marked the end of four years of declining hole area.
Ushuaia keeps track of the ozone layer hole with the Global Atmospheric Vigilance which makes weekly surveys the situation. The program is supported by several Argentine scientific organizations and Spain's Aerospace Technical Institute, INTA and the Meteorology State Agency from Spain.