Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Puzzling height of polar clouds revealed

26.01.2004


Scientists have discovered why icy clouds found at the edge of space are higher at the South Pole than at the North. The answer to this puzzle is that the intensity of solar radiation at the South Pole is six percent higher than at the North Pole during the austral summer, as the Earth comes closer to the sun. New research from British Antarctic Survey and University of Illinois is reported in this month’s Geophysical Research Letters (published online 29 January 2004). This research helps understand the role of these clouds as indicators of climate change.



Polar mesospheric clouds form at an altitude of 52 miles at the summertime polar caps when temperatures in the mesosphere fall below -125 degrees Celsius. Scientists were puzzled why clouds at the South Pole were on average consistently two miles higher than those found in the North. To confirm these geographic differences, measurements were taken at British Antarctic Survey’s Rothera Research Station, 1500 miles from the South Pole, at the same latitude as measurements made in the northern hemisphere (68°). Using a laser radar (LIDAR) to bounce light pulses off the clouds and measure their distance from earth, the researchers demonstrated that even though the clouds were slightly lower at Rothera than at the South Pole, they were considerably higher than at similar latitudes in the northern hemisphere.

Since the Earth’s orbit is not exactly circular, solar radiation at the South Pole is six percent higher that at the North as the Earth orbits the Sun. Using a model to explore temperature and vertical wind distribution, the researchers concluded that this increased solar input heats the polar ozone and creates a vertical upwelling that forces the clouds up higher than in the north.


Polar mesospheric clouds have brightened by approximately 15% over the last twenty years demonstrating a cooling of the mesosphere. This cooling intensifies as the atmosphere near the Earth’s surface warms, so polar mesospheric clouds may be an indicator of long-term global climate change.

Pat Espy, scientist at the British Antarctic Survey explains: "The growing brightness of polar mesospheric clouds is attributed to increasing levels of atmospheric carbon dioxide and methane, which in the upper atmosphere makes the Earth a more efficient radiator leading to cooler temperatures. By understanding more about how and where these clouds form scientists can use them as a measurement of long-term global climate change."

Espy and his team took measurements using a LIDAR (Light Detecting and Ranging System), which transmits a light beam up to 52 miles into the mesosphere.

Athena Dinar | alfa
Further information:
http://www.antarctica.ac.uk

More articles from Earth Sciences:

nachricht Predicting unpredictability: Information theory offers new way to read ice cores
07.12.2016 | Santa Fe Institute

nachricht Sea ice hit record lows in November
07.12.2016 | University of Colorado at Boulder

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

NTU scientists build new ultrasound device using 3-D printing technology

07.12.2016 | Health and Medicine

The balancing act: An enzyme that links endocytosis to membrane recycling

07.12.2016 | Life Sciences

How to turn white fat brown

07.12.2016 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>