Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Satellite instrument helps tackle mysteries of ozone-eating clouds

11.04.2006


Polar stratospheric clouds have become the focus of many research projects in recent years due to the discovery of their role in ozone depletion, but essential aspects of these clouds remain a mystery. MIPAS, an instrument onboard ESA’s Envisat, is allowing scientists to gain information about these clouds necessary for modelling ozone loss.



"The Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) is unique in its possibilities to detect polar stratospheric clouds (PSCs) since it is the first instrument with the ability to observe these clouds continuously over the polar regions especially during the polar night," Michael Höpfner of Germany’s Forschungszentrum Karlsruhe GmbH said.

Using data collected by MIPAS, a German-designed instrument that observes the atmosphere in middle infrared range, Höpfner and other scientists discovered a belt of nitric acid trihydrate (NAT) PSCs developing in the polar night over Antarctica in 2003 about one month after the first PSCs, which were composed of water crystals, were detected.


There are two classifications of PSCs – Type I clouds contain hydrated droplets of nitric acid and sulphuric acid, while Type II clouds consist of relatively pure water ice crystals.

The presence of NAT was detected because of MIPAS’ ability to map the atmospheric concentrations of more than 20 trace gases, including ozone as well as the pollutants that attack it.

"This has been the first evidence for the existence of NAT PSCs on a large scale," Höpfner said. NAT particles, which contain three molecules of water and one molecule of nitric acid, enhance the potential for ozone destruction in polar regions.

The thinning of the ozone is caused by the presence of man-made pollutants in the atmosphere such as chlorine, originating from man-made pollutants like chlorofluorocarbons (CFCs). During the southern hemisphere winter, temperatures drop to very low levels causing the chemicals in the stratosphere, which is in complete darkness during the winter, to freeze and form PSCs that contain chlorine.

Now banned under the Montreal Protocol, CFCs were once widely used in aerosol cans and refrigerators – and have not vanished from the air. CFCs themselves are inert, but ultraviolet radiation high in the atmosphere breaks them down into their constituent parts, which can be highly reactive with ozone.

As the polar spring arrives, sunlight returns and creates chemical reactions in PSCs responsible for converting benign forms of chlorine into highly ozone-reactive radicals that spur ozone depletion. A single molecule of chlorine has the potential to break down thousands of molecules of ozone.

NAT PSCs enhance the potential for chlorine activation and can also sediment and irreversibly remove nitrogen from the lower stratosphere, causing a process known as denitrification, which slows the return of chlorine to its inactive form and allows for ozone destruction to continue.

Höpfner and fellow scientists were able to explain the sudden NAT formation of PSCs in 2003 by temperature disturbances in waves over the Antarctic Peninsula and the Ellsworth Mountains, suggesting a more significant role for mountain waves in the formation of Antarctic’s PSCs than previously thought.

According to Höpfner, the presence of PSCs could intensify in the future due to a globally changing climate where the Earth’s surface gets warmer due to trapped greenhouse gases but the stratosphere gets colder, providing an environment in which the clouds can form. An increase in PSCs could counteract the recovery of the ozone layer.

Although scientific efforts have focused on determining PSC composition and their formation mechanisms, the process causing the ozone depletion is far from understood. In order to gain a better understanding of ozone depletion, scientists must continue obtaining data which allows them to measure the key species involved in the process.

Mariangela D’Acunto | alfa
Further information:
http://www.esa.int/esaEO/SEMBZNNFGLE_planet_0.html

More articles from Ecology, The Environment and Conservation:

nachricht Global threat to primates concerns us all
19.01.2017 | Deutsches Primatenzentrum GmbH - Leibniz-Institut für Primatenforschung

nachricht Reducing household waste with less energy
18.01.2017 | FIZ Karlsruhe – Leibniz-Institut für Informationsinfrastruktur GmbH

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

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

Im Focus: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

New Study Will Help Find the Best Locations for Thermal Power Stations in Iceland

19.01.2017 | Earth Sciences

Not of Divided Mind

19.01.2017 | Life Sciences

Molecule flash mob

19.01.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>