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Antarctic Ozone Hole in 2005
| Title |
Antarctic Ozone Hole in 2005 |
| Abstract |
A relatively warm Antarctic winter in 2005 kept the thinning of the protective ozone layer over Antarctica, known as the 'ozone hole', slightly smaller than in 2004. The ozone hole is not technically a 'hole' where no ozone is present, but is actually a region of exceptionally depleted ozone in the stratosphere over the Antarctic that happens at the beginning of Southern Hemisphere spring (August-October). The average concentration of ozone in the atmosphere is about 300 Dobson Units, any area where the concentration drops below 220 Dobson Units is considered part of the ozone hole. Each year the 'hole' expands over Antarctica, sometimes reaching populated areas of South America and exposing them to ultraviolet rays normally absorbed by ozone. The data in these omages were acquired by the Ozone Monitoring Instrument on NASA's Aura satellite. On September 11, 2005, ozone thinning over Antarctica reached its maximum extent for the year at 27 millions of square kilometers. On October 1, 2005 the minimum ozone value was recorded at 102 Dobson Units. |
| Completed |
2005-11-01 |
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Antarctic Ozone Hole in 2005
| Title |
Antarctic Ozone Hole in 2005 |
| Abstract |
A relatively warm Antarctic winter in 2005 kept the thinning of the protective ozone layer over Antarctica, known as the 'ozone hole', slightly smaller than in 2004. The ozone hole is not technically a 'hole' where no ozone is present, but is actually a region of exceptionally depleted ozone in the stratosphere over the Antarctic that happens at the beginning of Southern Hemisphere spring (August-October). The average concentration of ozone in the atmosphere is about 300 Dobson Units, any area where the concentration drops below 220 Dobson Units is considered part of the ozone hole. Each year the 'hole' expands over Antarctica, sometimes reaching populated areas of South America and exposing them to ultraviolet rays normally absorbed by ozone. The data in these omages were acquired by the Ozone Monitoring Instrument on NASA's Aura satellite. On September 11, 2005, ozone thinning over Antarctica reached its maximum extent for the year at 27 millions of square kilometers. On October 1, 2005 the minimum ozone value was recorded at 102 Dobson Units. |
| Completed |
2005-11-01 |
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Eruption of Santa Ana (Ilama
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| Title |
Eruption of Santa Ana (Ilamatepec) Volcano |
| Description |
On October 1, 2005, El Salvador's Santa Ana, or Ilamatepec, Volcano erupted for the first time since 1904. Besides ash, lava, rocks as big as cars, and a boiling flood of muddy water, Santa Ana's eruption produced something else: sulfur dioxide. This invisible gas can inflame mucous membranes of the eyes, skin, and upper respiratory tract. It also leads to acid rain and volcanic smog (vog) that interferes with air transport. The Ozone Monitoring Instrument (OMI) on NASA's Aura [ http://aura.gsfc.nasa.gov/index.html ] satellite collects data on atmospheric chemistry, including sulfur dioxide emissions from volcanoes. This image combines OMI's observations of the Santa Ana Volcano taken on October 1 and 2, 2005. In this image of Central America, black triangles indicate volcanoes. Sulfur dioxide concentrations are color coded, with highest concentrations in red, and lowest concentrations in pale pink. Near the Santa Ana Volcano hovers a thick cloud of sulfur dioxide, this is the emission cloud as it appeared on October 1. To the left is a dispersed cloud, this is how the same cloud appeared on October 2 as the gas drifted westward over the Pacific, having lost half of its sulfur dioxide mass. The total cloud mass on October 1 was estimated at 10,000 tons, a relatively small eruption. Recent examples of much larger eruptions include Manam [ http://earthobservatory.nasa.gov/Newsroom/NewImages/images.php3?img_id=16820 ] on January 27-28, 2005, and Anatahan [ http://earthobservatory.nasa.gov/NaturalHazards/natural_hazards_v2.php3?img_id=12854 ] on April 5-6, 2005. The OMI instrument is a Dutch-Finnish Instrument, provided to the EOS/Aura mission by The Netherlands and Finland. NIVR (the Dutch space agency) is the overall program manager, in coordination with FMI (the Finnish Meteorological Institute). The Royal Netherlands Meteorological Institute (KNMI) is the Principal Investigator institute. NASA image courtesy Simon Carn, Joint Center for Earth Systems Technology [ http://www.jcet.umbc.edu/ ] (JCET), University of Maryland Baltimore County (UMBC) |
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