Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Mountainous plateau creates ozone ’halo’ around Tibet

09.12.2005


Levels of ozone at extreme altitudes may add to the medical dangers faced by mountaineers



Not only is the air around the world’s highest mountains thin, but it’s thick with ozone, says a new study from University of Toronto researchers.

In fact, say the scientists, the ring of ozone that exists around the Tibetan plateau, which rises 4,000 metres above sea level and includes such famous peaks as Mount Everest and K2, is as concentrated as the ozone found in heavily polluted cities -- and may put climbers at risk. The findings are published in the journal Geophysical Research Letters.


"Around the circumference of Tibet, there’s a halo of very high levels of ozone," said Professor G.W. Kent Moore, interim chair of the Department of Chemical and Physical Sciences at the University of Toronto at Mississauga and lead author of the study.

Study co-author John Semple, an associate professor of surgery and an avid mountaineer, was initially interested in how weather changes at high altitude can have a medical impact on climbers. Along with Moore, he examined earlier data and found several studies that alluded to higher ozone levels. Ozone is a highly reactive gas that can cause coughing, chest pain and damage to the lining of the lungs.

"In meteorology, it’s a fairly well known phenomenon that when you get storms, quite often the tropopause -- which is the flexible boundary between the stratosphere and the troposphere -- descends," Moore says. "Its usual height might be 12 kilometres, and it might decend to nine or 10 kilometres. If you’re on Mount Everest, you’re eight or nine kilometres up. It might be that you’re sometimes in the stratosphere."

The stratosphere is where most of the ozone that protects the globe from the sun’s ultraviolet rays can be found;for this reason stratospheric ozone is often referred to as "good" as opposed to the ground-level ozone from pollution which is referred to as "bad". When the tropopause decends, the ozone descends with it. "Most people think about the mountains as one of the areas you can go to get clean air," said Semple, head of the Division of Plastic Surgery at Sunnybrook and Women’s College Health Sciences Centre, a teaching hospital affiliated with U of T. "It may be that when you’re up high in the mountains that the good ozone actually becomes bad ozone--because no matter where ozone comes from you don’t want to breathe it."

Semple climbed the Yeli Pass in Bhutan in the autumn of 2004 while collecting data on weather and atmospheric changes. He measured the levels of ozone between 3,000 and 5,000 metres above sea level and discovered that instead of falling (as pollutant levels normally do with altitude), ozone levels were rising.

Moore examined satellite measurements of the ozone levels above the plateau during October and November of the years 1997 to 2004. He found that while ozone levels were low over the centre of the Tibetan plateau, high levels of the gas could be found around the periphery of the plateau -- forming a halo.

Moore believes that the halo is the result of a pattern in fluid dynamics known as a Taylor column -- a phenomenon that is normally seen underwater. When water passes around a submerged obstacle, like a seamount, the flow of water forks around the obstacle. This forked pattern also continues above the top of the obstruction to the surface of the water, leaving a column of still water above the object.

Scientists treat air as a fluid, and Moore says that the Tibetan plateau acts like an obstacle, creating a column of stagnant air above the mountainous region. Because the plateau’s influence extends into the upper troposphere and the lower stratosphere -- where the Earth’s layer of UV-protectant ozone resides, Moore suggests that the plateau forms a halo of ozone-rich air in the upper-troposphere around Tibet. "As far as we know, this is the first one that’s ever been found in the atmosphere," he says.

The ozone concentrations measured in this study are still considered quite low in relation to levels that are known to cause significant changes in lung function at sea level. The presence of such higher levels of ozone at extreme altitudes may add to the medical dangers faced by mountaineers. "We can only imagine that hypoxia [lack of oxygen] and the rate of hyperventilation that people have at extreme altitudes would actually make the effects of ozone worse," Semple says. "You probably need less ozone to cause a significant change in the lungs."

Nicolle Wahl | EurekAlert!
Further information:
http://www.utoronto.ca

More articles from Earth Sciences:

nachricht Turning the Climate Tide by 2020
29.06.2017 | Potsdam-Institut für Klimafolgenforschung

nachricht Predicting eruptions using satellites and math
28.06.2017 | Frontiers

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

High conductive foils enabling large area lighting

29.06.2017 | Power and Electrical Engineering

Designed proteins to treat muscular dystrophy

29.06.2017 | Life Sciences

Climate Fluctuations & Non-equilibrium Statistical Mechanics: An Interdisciplinary Dialog

29.06.2017 | Seminars Workshops

VideoLinks
B2B-VideoLinks
More VideoLinks >>>