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 Worldwide Success of Tyrolean Wastewater Treatment Technology
27.05.2016 | Universität Innsbruck

nachricht How nanoparticles flow through the environment
12.05.2016 | Schweizerischer Nationalfonds SNF

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: Worldwide Success of Tyrolean Wastewater Treatment Technology

A biological and energy-efficient process, developed and patented by the University of Innsbruck, converts nitrogen compounds in wastewater treatment facilities into harmless atmospheric nitrogen gas. This innovative technology is now being refined and marketed jointly with the United States’ DC Water and Sewer Authority (DC Water). The largest DEMON®-system in a wastewater treatment plant is currently being built in Washington, DC.

The DEMON®-system was developed and patented by the University of Innsbruck 11 years ago. Today this successful technology has been implemented in about 70...

Im Focus: Computational high-throughput screening finds hard magnets containing less rare earth elements

Permanent magnets are very important for technologies of the future like electromobility and renewable energy, and rare earth elements (REE) are necessary for their manufacture. The Fraunhofer Institute for Mechanics of Materials IWM in Freiburg, Germany, has now succeeded in identifying promising approaches and materials for new permanent magnets through use of an in-house simulation process based on high-throughput screening (HTS). The team was able to improve magnetic properties this way and at the same time replaced REE with elements that are less expensive and readily available. The results were published in the online technical journal “Scientific Reports”.

The starting point for IWM researchers Wolfgang Körner, Georg Krugel, and Christian Elsässer was a neodymium-iron-nitrogen compound based on a type of...

Im Focus: Atomic precision: technologies for the next-but-one generation of microchips

In the Beyond EUV project, the Fraunhofer Institutes for Laser Technology ILT in Aachen and for Applied Optics and Precision Engineering IOF in Jena are developing key technologies for the manufacture of a new generation of microchips using EUV radiation at a wavelength of 6.7 nm. The resulting structures are barely thicker than single atoms, and they make it possible to produce extremely integrated circuits for such items as wearables or mind-controlled prosthetic limbs.

In 1965 Gordon Moore formulated the law that came to be named after him, which states that the complexity of integrated circuits doubles every one to two...

Im Focus: Researchers demonstrate size quantization of Dirac fermions in graphene

Characterization of high-quality material reveals important details relevant to next generation nanoelectronic devices

Quantum mechanics is the field of physics governing the behavior of things on atomic scales, where things work very differently from our everyday world.

Im Focus: Graphene: A quantum of current

When current comes in discrete packages: Viennese scientists unravel the quantum properties of the carbon material graphene

In 2010 the Nobel Prize in physics was awarded for the discovery of the exceptional material graphene, which consists of a single layer of carbon atoms...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Networking 4.0: International Laser Technology Congress AKL’16 Shows New Ways of Cooperations

24.05.2016 | Event News

Challenges of rural labor markets

20.05.2016 | Event News

International expert meeting “Health Business Connect” in France

19.05.2016 | Event News

 
Latest News

11 million Euros for research into magnetic field sensors for medical diagnostics

27.05.2016 | Awards Funding

Fungi – a promising source of chemical diversity

27.05.2016 | Life Sciences

New Model of T Cell Activation

27.05.2016 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>