In March 2006, the winds allowed near-record amounts of ozone- destroying gases, collectively known as nitrogen oxides or NOx, to descend some 50 kilometers [30 miles] from the mesosphere to the top of Earth's stratosphere.
NOx, is a generic term for a group of highly reactive gases, all of which contain nitrogen and oxygen in varying amounts, especially nitric oxide and nitrogen dioxide. Because NOx destroys ozone, which heats up the stratosphere by absorbing ultraviolet radiation, the naturally occurring gases could trigger atmospheric changes that could have unanticipated climate consequences, according to Cora Randall of the University of Colorado at Boulder, lead author of the study.
In February 2006, winds in the polar upper stratospheric vortex, a massive winter low-pressure system that confines air over the Arctic region, sped up to rival the strongest such winds on record, said Randall. The only time more nitrogen oxides were observed in the upper stratosphere was in the winter of 2003-2004, when huge solar storms bombarded the region with energetic particles, triggering up to a 60 percent reduction in ozone molecules, said Randall.
"We knew strong winds would lead to more NOx in the stratosphere if there were solar storms, but seeing that much NOx come down into the stratosphere when the Sun was essentially quiet was amazing,” Randall said. Her paper on the subject was published 27 September in Geophysical Research Letters, published by the American Geophysical Union. Researchers from the University of Waterloo in Ontario, Canada, and the University of Michigan, as well as the University of Colorado participated in the study.
The upper stratosphere lies several kilometers [miles] higher than the ozone hole of the lower stratosphere, which is caused by man- made gases, including chlorine and bromine, which gobble up ozone molecules. Because there is significantly less ozone in the upper stratosphere, the ozone-destroying nitrogen oxide gases are unlikely to cause immediate health threats, such as increases in skin cancer, Randall said.
The destructive NOx gases, created above the stratosphere when sunlight or energetic particles break apart oxygen and nitrogen molecules, appear to be important players in controlling the temperature of Earth's middle atmosphere, according to Randall. "If human-induced climate change leads to changes in the strength of the polar vortex, which is what scientists predict, we'll likely see changes in the amount of NOx descending into the stratosphere,” she said. "If that happens, more stratospheric NOx might become the rule rather than the exception."
"The atmosphere is part of a coupled system, and what affects one layer of the atmosphere can influence other layers in surprising ways," Randall said. "We will only be able to predict and understand the consequences of human activities if we study the entire system as a whole, and not just in parts."
The 2006 increases of NOx in the upper stratosphere occurred over the Arctic and the northern areas of North America and Europe, according to the paper's authors. The research team used data from Canadian and United States satellites, including the Canadian Atmospheric Chemistry Experiment.
The work was funded by NASA and the Canadian Space Agency.
Harvey Leifert | AGU
Ice cave in Transylvania yields window into region's past
28.04.2017 | National Science Foundation
Citizen science campaign to aid disaster response
28.04.2017 | International Institute for Applied Systems Analysis (IIASA)
More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.
Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...
Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.
"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...
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...
28.04.2017 | Event News
20.04.2017 | Event News
18.04.2017 | Event News
28.04.2017 | Medical Engineering
28.04.2017 | Earth Sciences
28.04.2017 | Life Sciences