The ozone layer helps protect the planet’s surface from harmful ultraviolet radiation. NOAA and NASA use balloon-borne instruments, ground instruments, and satellites to monitor the annual South Pole ozone hole, global levels of ozone in the stratosphere, and the manmade chemicals that contribute to ozone depletion.
Ozone levels in the atmosphere above the South Pole dropped to a seasonal low of 102 Dobson Units Oct. 9, tied for the 10th lowest in the 26-year record. The ozone layer helps protect the planet’s surface from harmful ultraviolet radiation. Every year, an ozone hole forms above the Antarctic for several weeks, because of environmental conditions and the presence of ozone-depleting chemicals. (Credit: NOAA)
“The upper part of the atmosphere over the South Pole was colder than average this season and that cold air is one of the key ingredients for ozone destruction,” said James Butler, director of NOAA’s Global Monitoring Division in Boulder, Colo. Other key ingredients are ozone-depleting chemicals that remain in the atmosphere and ice crystals on which ozone-depleting chemical reactions take place.
“Even though it was relatively large, the size of this year's ozone hole was within the range we'd expect given the levels of manmade, ozone-depleting chemicals that continue to persist," said Paul Newman, chief atmospheric scientist at NASA's Goddard Space Flight Center.
Levels of most ozone-depleting chemicals are slowly declining due to international action, but many have long lifetimes, remaining in the atmosphere for decades. Scientists around the world are looking for evidence that the ozone layer is beginning to heal, but this year’s data from Antarctica do not hint at a turnaround.In August and September (spring in Antarctica), the sun begins rising again after several months of darkness. Circumpolar winds keep cold air trapped above the continent, and sunlight-sparked reactions involving ice clouds and manmade chemicals begin eating away at the ozone. Most years, the conditions for ozone depletion ease by early December, and the seasonal hole closes.
Global atmospheric models predict that stratospheric ozone could recover by the middle of this century, but the ozone hole in the Antarctic will likely persist one to two decades beyond that, according to the latest analysis by the World Meteorological Organization, the 2010 Ozone Assessment, with co-authors from NOAA and NASA.
Researchers do not expect a smooth, steady recovery of Antarctic ozone, because of natural ups and downs in temperatures and other factors that affect depletion, noted NOAA ESRL scientist Bryan Johnson. Johnson helped co-author a recent NOAA paper that concluded it could take another decade to begin discerning changes in the rates of ozone depletion.
Johnson is part of the NOAA team tracks ozone depletion around the globe and at the South Pole with measurements made from the ground, in the atmosphere itself and by satellite. Johnson’s “ozonesonde” group has been using balloons to loft instruments 18 miles into the atmosphere for 26 years to collect detailed profiles of ozone levels from the surface up. The team also measures ozone with satellite and ground-based instruments.
This November marks the 50th anniversary of the start of total ozone column measurements by the NOAA Dobson spectrophotometer instrument at South Pole station. Ground-based ozone column measurements started nearly two decades before the yearly Antarctic ozone hole began forming, therefore helping researchers to recognize this unusual change of the ozone layer.
NASA measures ozone in the stratosphere with the Ozone Monitoring Instrument (OMI) aboard the Aura satellite. OMI continues a NASA legacy of monitoring the ozone layer from space that dates back to 1972 and the launch of the Nimbus-4 satellite.
A new satellite scheduled to launch this month, the NPP satellite, features a new ozone-monitoring instrument, the Ozone Mapping and Profiler Suite, which will provide more detailed daily, global ozone measurements than ever before to continue the task of observing the ozone layer's gradual recovery. The NPP satellite is part of Joint Polar Satellite System, a program of NOAA, NASA and the Department of Defense (formerly known as the NPOESS Preparatory Project). It is scheduled to launch October 27 from Vandenberg Air Force Base in California.
NOAA’s mission is to understand and predict changes in the Earth's environment, from the depths of the ocean to the surface of the sun, and to conserve and manage our coastal and marine resources. Join us on Facebook, Twitter and our other social media channels.
Katy Human | EurekAlert!
NASA sees the end of ex-Tropical Cyclone 02W
21.04.2017 | NASA/Goddard Space Flight Center
New research unlocks forests' potential in climate change mitigation
21.04.2017 | Clemson University
The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.
Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...
The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...
Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.
Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...
Two researchers at Heidelberg University have developed a model system that enables a better understanding of the processes in a quantum-physical experiment...
Glaciers might seem rather inhospitable environments. However, they are home to a diverse and vibrant microbial community. It’s becoming increasingly clear that they play a bigger role in the carbon cycle than previously thought.
A new study, now published in the journal Nature Geoscience, shows how microbial communities in melting glaciers contribute to the Earth’s carbon cycle, a...
20.04.2017 | Event News
18.04.2017 | Event News
03.04.2017 | Event News
21.04.2017 | Physics and Astronomy
21.04.2017 | Health and Medicine
21.04.2017 | Physics and Astronomy