Unexpected discovery could impact on future climate models

February 10, 2009
Dust plumes blowing off the coast of Western Sahara over the Atlantic Ocean. Credit: NASA/NOAA

(PhysOrg.com) -- Astronomers have made an unexpected find using a polarimeter (an instrument used to measure the wave properties of light) funded by the Science and Technology Facilities Council (STFC), that has the potential to affect future climate models.

University of Hertfordshire astronomers were making observations of the stars in search of new planets after mounting the 'PlanetPol' (polarimeter they designed and constructed to take extremely sensitive readings) on the William Herschel Telescope (part of the Isaac Newton Group of Telescopes) in La Palma in the Canary Islands, when their measurements became affected by a layer of dust.

The presence of the dust itself, which satellite images and modelling of the dust's movement show had originated from the Sahara and the Sahel, was not a surprise, but its behaviour was. Scientists normally assume that aerosols, including mineral dust, have random orientation in the atmosphere, but the team members say the polarizing affect the dust was having on the light could only be the result of dust particles being vertically aligned.

Furthermore, electric fields that are now thought to be responsible for this phenomenon are likely to affect the transport of dust over long distances. For the first time this might explain why large Saharan dust grains can travel as far as the UK instead of falling to the ground long before.

This could impact on climate theories because atmospheric dust is a significant source of uncertainty for scientists trying to model the climate. 'If it's proven the dust is affected by electric fields, elements of current climate models may have to be re-worked with this new information, to remain accurate', explains Joseph Ulanowski, Centre for Atmospheric and Instrumentation Research (CAIR) at the University of Hertfordshire.

Climate models are extremely complex and involve many other influences, so further research will now be carried out to see how significant a find this dust phenomenon is. CAIR will now join a Met Office-led campaign in the Middle East in the spring 2009 which presents an opportunity to investigate this further.

Professor James Hough, Director of Astronomy Research at the University of Hertfordshire said, 'It's been fascinating to see how we have been able to use astronomical observations to learn far more about dust in the Earth's atmosphere, especially as we first considered the Saharan dust event to be a real nuisance and of no value to us at all.'

Provided by University of Hertfordshire

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3 / 5 (6) Feb 10, 2009
This unusual alignment of dust has already been allowed for in the global climate models since the science is settled. Please do not try to confuse the public.
Obliterating Evil CO2 for you and your progeny,
4 / 5 (5) Feb 10, 2009
All hail Mike, he who bringeth the ice water 'pon the naked and ignorant bodies of the Evil CO2'ers.
3.5 / 5 (2) Feb 10, 2009
Regardless of climate "models", actual weather forecasting may actually be improved by this new information.
2.8 / 5 (4) Feb 10, 2009
You cannot improve upon guessing the weather, and the other planets are heating up also, human CO2?
5 / 5 (1) Feb 10, 2009
Ave Caesar morituri te salutant!
2.7 / 5 (3) Feb 10, 2009
solar cycle?
2 / 5 (3) Feb 10, 2009
solar cycle?

Bingo. Give the man a cookie.
2.8 / 5 (4) Feb 11, 2009
Finally, an article about climate that breaks new ground without throwing around a bunch of alarmist scenarios about the imminent extinction of the striped unicorn. I gave it a five because it shows that not everyone in the field is a loonie.
3.4 / 5 (5) Feb 11, 2009
hmmm, I see these were astronomers, i.e. actual scientists, not eco-climatologists bandying about "Will produce even more alarming scenarios for funding" signs. That explains it. :-)
3.7 / 5 (6) Feb 11, 2009
It's easier to tell the truth when Al doesn't have a tight grip on your purse.
1 / 5 (4) Feb 13, 2009
Or the owners of coal mines.....

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