Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Effect of important air pollutants may be absent from key precipitation observations

31.03.2014

Pioneering new research from the University of Exeter could have a major impact on climate and environmental science by drastically transforming the perceived reliability of key observations of precipitation, which includes rain, sleet and snow.

The ground breaking study examines the effect that increased aerosol concentrations in the atmosphere, emitted as a result of burning fossil fuels, had on regional temperature and precipitation levels.

Scientists from Exeter's Mathematics department compared observed regional temperature and precipitation changes throughout the 20th century with results produced by the latest complex climate models over the same period.

The study showed that the observed regional temperature changes, as well as observed precipitation levels in the tropics, were in agreement with the range of the modelled responses given current best estimates of the influence of aerosols on the Earth's energy budget.

However, when looking at geographical areas within the Northern Hemisphere mid-latitudes – which includes Europe, much of North Asia and North America – the study showed a significant discrepancy between observed precipitation levels and those predicted from the models.

This new analysis could transform our understanding of observed changes in the local hydrological cycle and offer a unique opportunity to correct for potential biases in measurements.

The new study, published in leading scientific journal Nature Climate Change, was produced by Joe Osborne and Dr Hugo Lambert, from Exeter's College of Engineering, Mathematics and Physical Sciences.

Dr Lambert explained: "Scientists have known that observed mid-latitude precipitation trends may be in error for many years. Our new physical framework fits together temperature changes, aerosol changes and other precipitation changes to show by how much. We now have the opportunity to correct 20th century precipitation trends."

The concentration of human-made aerosols in the atmosphere increased rapidly in the decades following the Second World War. Although aerosols interact with clouds and precipitation in complex ways, the primary effect is to reflect sunlight and cool the planet's surface. Hence, physical theory and modelling suggest there are robust expectations for regional temperature and precipitation change.

The study showed that climate models replicate the mid-twentieth-century fall in temperature linked to increased aerosol concentrations that is seen in observations.

It also showed that models and observations were in agreement over a reduction in rainfall in the Northern Hemisphere tropics around the same time, which is associated with the severe Sahel drought of the 1970s.

However, there was a dramatic discrepancy between the expected change in precipitation across the Northern Hemisphere mid-latitudes – where industrialisation occurred most heavily in the 20th century – and observations. While the modelling and physical theory suggested precipitation should fall, observations suggest that it increased.

Joe, a PhD student and lead author, explained the significance of the study. He said: "The study shows that precipitation in two key regions alters in line with mid-20th Century changes in aerosol across a number of the latest climate models. This can be understood in terms of the aerosol influence on the amount of energy received at the Earth's surface and consequent changes in atmospheric circulation.

"However, we also show that the response of precipitation observations in the mid-latitudes is not as we might have expected, given the models and our understanding."

###

The missing aerosol response in twentieth-century mid-latitude precipitation observations by Joe Osborne and Dr Hugo Lambert is published in Nature Climate Change.

Please not the strict embargo in place - 18.00 (GMT) on Sunday 30 March 2014

For further information please contact:

Duncan Sandes
Press Officer
+44 (0) 1392 722391/ 722062
d.sandes@exeter.ac.uk

About the University of Exeter

The University of Exeter is a Russell Group university and in the top one percent of institutions globally. It combines world-class research with very high levels of student satisfaction. Exeter has over 18,000 students and is ranked 8th in The Times and The Sunday Times Good University Guide league table, 10th in The Complete University Guide and 12th in the Guardian University Guide 2014. In the 2008 Research Assessment Exercise (RAE) 90% of the University's research was rated as being at internationally recognised levels and 16 of its 31 subjects are ranked in the top 10, with 27 subjects ranked in the top 20. Exeter was The Sunday Times University of the Year 2012-13.

The University has invested strategically to deliver more than £350 million worth of new facilities across its campuses in the last few years; including landmark new student services centres - the Forum in Exeter and The Exchange on the Penryn Campus in Cornwall, together with world-class new facilities for Biosciences, the Business School and the Environment and Sustainability Institute. There are plans for another £330 million of investment between now and 2016.

http://www.exeter.ac.uk

Duncan Sandes | EurekAlert!

Further reports about: Climate Exeter Hemisphere concentrations observations pollutants precipitation temperature

More articles from Ecology, The Environment and Conservation:

nachricht Upcycling 'fast fashion' to reduce waste and pollution
03.04.2017 | American Chemical Society

nachricht Litter is present throughout the world’s oceans: 1,220 species affected
27.03.2017 | Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung

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: Making lightweight construction suitable for series production

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...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

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...

Im Focus: Deep inside Galaxy M87

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...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

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...

Im Focus: Microprocessors based on a layer of just three atoms

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...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

7th International Conference on Crystalline Silicon Photovoltaics in Freiburg on April 3-5, 2017

03.04.2017 | Event News

 
Latest News

Bare bones: Making bones transparent

27.04.2017 | Life Sciences

Study offers new theoretical approach to describing non-equilibrium phase transitions

27.04.2017 | Physics and Astronomy

From volcano's slope, NASA instrument looks sky high and to the future

27.04.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>