Please select your home edition
Edition
Barz Optics - Kids range

Aerosols – their part in our rainfall

by CSIRO on 17 Feb 2009
CSIRO atmosphere expert, Dr Leon Rotstayn. Photo: Bruce Miller © Copyright CSIRO Australia http://www.csiro.au
Aerosols may have a greater impact on patterns of Australian rainfall and future climate change than previously thought, according to leading atmospheric scientist, CSIRO’s Dr Leon Rotstayn.

'We have identified that the extensive pollution haze emanating from Asia may be re-shaping rainfall patterns in northern Australia but we wonder what impact natural and human-generated aerosols are having across the rest of the country,' Dr Rotstayn said.

Aerosols are fine particles suspended in the atmosphere. Sources of human-generated aerosols include industry, motor vehicles and vegetation burning. Natural sources include volcanoes, dust storms and ocean plankton. Human-generated aerosols have long been known to exert a cooling effect on climate. This has partly masked the warming effect of increasing greenhouse gases. As aerosol pollution is predicted to decrease over the next few decades, unmasking of the greenhouse effect may lead to accelerated global warming.

However, in an address to the International Conference on Southern Hemisphere Meteorology and Oceanography in Melbourne, Dr Rotstayn said aerosols are much more than a 'negative greenhouse gas' because they can actively force changes in winds and ocean currents by altering the distribution of solar heating at the earth’s surface.

'We have identified that the extensive pollution haze emanating from Asia may be re-shaping rainfall patterns in northern Australia but we wonder what impact natural and human-generated aerosols are having across the rest of the country,'

Dr Rotstayn said 'Recent climate modelling at CSIRO shows that there may be important effects on Australian climate due to aerosol pollution from the Northern Hemisphere. These include an increase of rainfall in north-western Australia, and an increase of air pressure over southern Australia, which may have contributed to less rainfall there.

'New simulations with the CSIRO climate model also show big improvements in the simulation of El Niño and the associated natural rainfall variability over eastern Australia, when natural and human-generated aerosols are included in the model. Natural aerosol includes Australian dust, which may be the key factor that improved our simulation. A realistic simulation of natural rainfall variability is essential if a climate model is to be used to improve our understanding of Australian rainfall changes.'

Dr Rotstayn said that further research into how aerosols are influencing climate and rainfall patterns across Australia is critical to scientists’ ability to more accurately predict the longer-term effects of climate change.

'It is crucial to quantify the relative roles of different drivers of recent Australian rainfall changes. A rainfall decline attributed to natural variability will be a passing phenomenon, and changes forced by human-generated aerosols are likely to be more short-term than changes forced by increasing greenhouse gases. The implications for decision makers will be very different, depending on whether the drivers are long-term or short-term,' Dr Rotstayn said.

The Centre for Australian Weather and Climate Research (CAWCR) - http://www.cawcr.gov.au/research/spcv/research_areas.php

http://www.csiro.com.au
Wildwind 2016 660x82Bakewell-White Yacht DesignInSunSport - NZ

Related Articles

British entries on podium as Clipper Race returns after 11 months
UK entries triumphed to take all three podium places in the toughest edition yet of the longest ocean race on the planet Thousands of spectators lined the River Thames and packed St Katharine Docks to welcome home over 250 crew, representing 44 different nationalities, many of whom have been at sea for eleven months racing between six continents in the only challenge of its kind for amateur sailors.
Posted on 30 Jul
LMAX Exchange wins the Clipper 2015-16 Round the World Yacht Race
LMAX Exchange was confirmed last night as winner of Clipper 2015-16 Round the World Yacht Race. LMAX Exchange, skippered by Frenchman Olivier Cardin, was confirmed last night as winner of the tenth edition of the world’s longest ocean race, the Clipper 2015-16 Round the World Yacht Race.
Posted on 30 Jul
Clipper Race – Constant trimming and little sleep in the North Sea
There is little opportunity for tactical moves and the timings of tacks are crucial if teams want to make vital gains. After a downwind start with spinnakers trimmed in light airs against the tide off Den Helder on the Dutch coast yesterday, the fleet has been match racing across the North Sea towards the Thames Estuary.
Posted on 29 Jul
Debriefing the 2015-16 Clipper Round The World Race with Huw Fernie
Sail-World talked with Huw Fernie of Visit Seattle to learn more about a Clipper Round The World Race skipper’s life. Skipper Huw Fernie and his Visit Seattle crew took top honors in the Den Helder Northern Seas Challenge, marking their second podium finish during the 2015/16 Clipper Round The World Race. I recently caught up with Fernie to learn more about Visit Seattle’s success in the Den Helder Northern Seas Challenge, and to learn more about the life of a Clipper Round The World Race skipper.
Posted on 28 Jul
Finale of Clipper Race global series starts in The Netherlands
The 198nm race to London is going to be one of the most nail-biting yet with just six points separating the top teams After a Departure Ceremony from Willemsoord Marina and a Parade of Sail in the presence of Dutch Royal Navy ship ZrMs Luymes, the fleet started the final short sprint to London off the Dutch coast.
Posted on 28 Jul
Thousands of spectators expected to welcome home Clipper Race fleet
Hurricane winds, giant waves, freezing conditions, battered boats and tragedy fail to quell fighting spirit of the crew. The tenth edition of the famous biennial race for novice sailors led by professional skippers is regarded as the most challenging on record after the event endured the most extreme conditions it has ever faced in its 20-year history.
Posted on 28 Jul
America's Cup World Series - Ian Roman's images of Pompey
Ian Roman was in Portsmouth for the America's Cup World Series capturing the Royal visitors Top international photographer, Ian Roman was in Portsmouth for the America's Cup World Series and provided this second of two galleries of the racing across the three days of the regatta, taking in the Royal visitors.
Posted on 26 Jul
America’s Cup World Series – More final day images by Ingrid Abery
Ingrid Abery has provided this gallery of images from final day Ingrid Abery has provided this gallery of images from final day
Posted on 25 Jul
America’s Cup World Series – Final race day images by Ingrid Abery
Ingrid Abery provided this gallery of images from final day Ingrid Abery provided this gallery of images from final day
Posted on 25 Jul
LV America’s Cup World Series - Up and down for Groupama Team France
The new leader is none other than the local team lead by Sir Ben Ainslie, who was rallied along throughout the six races 2016 America’s Cup World Series - This weekend the overall ranking for the Louis Vuitton America’s Cup World Series has been turned on its head and with the Portsmouth act complete, the new leader is none other than the local team lead by Sir Ben Ainslie, who was rallied along throughout the six races by strong support from a home crowd.
Posted on 25 Jul