Tech

October 26, 2012

2012 Antarctic ozone hole second smallest in 20 years

The average area covered by the Antarctic ozone hole this year was the second smallest in the last 20 years, according to data from NASA and National Oceanic and Atmospheric Administration satellites.

Scientists attribute the change to warmer temperatures in the Antarctic lower stratosphere.

The ozone hole reached its maximum size Sept. 22, covering 8.2 million square miles (21.2 million square kilometers), or the area of the United States, Canada and Mexico combined. The average size of the 2012 ozone hole was 6.9 million square miles (17.9 million square kilometers). The Sept. 6, 2000 ozone hole was the largest on record at 11.5 million square miles (29.9 million square kilometers).

“The ozone hole mainly is caused by chlorine from human-produced chemicals, and these chlorine levels are still sizable in the Antarctic stratosphere,” said NASA atmospheric scientist Paul Newman of NASA’s Goddard Space Flight Center in Greenbelt, Md. “Natural fluctuations in weather patterns resulted in warmer stratospheric temperatures this year. These temperatures led to a smaller ozone hole.”

The ozone layer acts as Earth’s natural shield against ultraviolet radiation, which can cause skin cancer. The ozone hole phenomenon began making a yearly appearance in the early 1980s. The Antarctic ozone layer likely will not return to its early 1980s state until about 2065, Newman said. The lengthy recovery is because of the long lifetimes of ozone-depleting substances in the atmosphere. Overall atmospheric ozone no longer is declining as concentrations of ozone-depleting substances decrease. The decrease is the result of an international agreement regulating the production of certain chemicals.

This year also showed a change in the concentration of ozone over the Antarctic. The minimum value of total ozone in the ozone hole was the second highest level in two decades. Total ozone, measured in Dobson units, reached 124 DU on Oct. 1. NOAA ground-based measurements at the South Pole recorded 136 DU on Oct. 5. When the ozone hole is not present, total ozone typically ranges from 240-500 DU.

This is the first year growth of the ozone hole has been observed by an ozone-monitoring instrument on the Suomi National Polar-orbiting Partnership (NPP) satellite. The instrument, called the Ozone Mapping Profiler Suite, is based on previous instruments, such as the Total Ozone Mapping Spectrometer and the Solar Backscatter Ultraviolet instrument, which have flown on multiple satellites. OMPS continues a satellite record dating back to the early 1970s.

In addition to observing the annual formation and extent of the ozone hole, scientists hope OMPS will help them better understand ozone destruction in the middle and upper stratosphere with its Nadir Profiler. Ozone variations in the lower stratosphere will be measured with its Limb Profiler.

“OMPS Limb looks sideways, and it can measure ozone as a function of height,” said Pawan K. Bhartia, a NASA atmospheric physicist and OMPS Limb instrument lead. “This OMPS instrument allows us to more closely see the vertical development of Antarctic ozone depletion in the lower stratosphere where the ozone hole occurs.”

NASA and NOAA have been monitoring the ozone layer on the ground and with a variety of instruments on satellites and balloons since the 1970s. Long-term ozone monitoring instruments have included TOMS, SBUV/2, Stratospheric Aerosol and Gas Experiment series of instruments, the Microwave Limb Sounder, the Ozone Monitoring Instrument, and the OMPS instrument on Suomi NPP. Suomi NPP is a bridging mission leading to the next-generation polar-orbiting environmental satellites called the Joint Polar Satellite System, will extend ozone monitoring into the 2030s.

NASA and NOAA have a mandate under the Clean Air Act to monitor ozone-depleting gases and stratospheric depletion of ozone. NOAA complies with this mandate by monitoring ozone via ground and satellite measurements. The NOAA Earth System Research Laboratory in Boulder, Colo., performs the ground-based monitoring. The Climate Prediction Center performs the satellite monitoring.

 

To monitor the state of the ozone layer above Antarctica, visit http://ozonewatch.gsfc.nasa.gov.

 




All of this week's top headlines to your email every Friday.


 
 

 

Headlines April 1, 2015

News: Iranian aircraft buzzed U.S. Navy helo in Persian Gulf - An Iranian aircraft buzzed a Navy helicopter operating in the Persian Gulf earlier this month, a U.S. military official said March 31. Active duty suicides up in 2014 - Suicides among active duty members of the military increased in 2014, though reservists and members of the...
 
 

News Briefs April 1, 2015

Germany, France, Italy plan to develop military drones Germany and France plan to work together with Italy to develop military surveillance drones that could also carry weapons. French President Francois Hollande said after meeting German Chancellor Angela Merkel March 31 that it is important for Europe to be independent in both manufacturing drones and in...
 
 
Northrop Grumman photograph

AirRobot, Northrop Grumman Remotec sign distribution agreement for unmanned aerial systems

Northrop Grumman photograph An AirRobot unmanned aerial system flies at Fort Benning, Ga.. Northrop Grumman Remotec is the sole reseller of the systems to law enforcement and first responders under a distribution agreement sign...
 

 

Raytheon awarded $528 million AMRAAM contract

Raytheon has been awarded a $528,797,459 fixed-price incentive, firm target contract modification for Advanced Medium Range Air-to-Air Missiles. Raytheon will provide AMRAAM Lot 29 missiles and other AMRAAM system items. This contract involves foreign military sales. Work will be performed in Tucson and is expected to be complete by January 2018. This award was booked...
 
 

Raytheon, DRS team for Army’s third Generation IFLIR B-Kit

Building on their combined platform integration experience, Raytheon and DRS Technologies have entered into a teaming agreement for the U.S. Army’s 3rd Generation Improved Forward Looking Infrared program B-Kit “Raytheon and DRS have teamed to provide an IFLIR solution that provides our military supremacy in reconnaissance, surveillance and target acquisition,” said Dr. Taylor...
 
 

U.S. Air Force awards Raytheon $91.5 million for MALD-J

Raytheon Company received a $91.5 million U.S. Air Force contract modification award for the Miniature Air Launched Decoy Jammer missile. The contract modification is for Lot 8. Work will be performed in Tucson and is expected to be complete by June 2017. This award was booked in the first quarter 2015. MALDÆ is a state-of-the-art,...
 




0 Comments


Be the first to comment!


Leave a Reply

Your email address will not be published. Required fields are marked *

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>