Water in a changing climateAugust 27, 2009Has northern-hemisphere pollution affected Australian rainfall? New research announced at the international Water in a changing climate science conference in Melbourne 24-28 August, implicates pollution from Asia, Europe and North America as a contributor to recent Australian rainfall changes. Australian scientists using a climate model that includes a treatment of tiny particles - or aerosols - report that the build up of these particles in the northern hemisphere affects their simulation of recent climate change in the southern hemisphere, including rainfall in Australia. The CSIRO climate model, which can include the effects of aerosols caused by humans, suggests that aerosols - whose major sources are in the northern hemisphere - can drive changes in atmospheric and oceanic circulation in the southern hemisphere. Their model results suggest that human-generated aerosols from the northern hemisphere may have contributed to increased rainfall in north-western and central Australia, and decreased rainfall in parts of southern Australia. Lead researcher, Dr Leon Rotstayn, Principal Research Scientist at the Centre for Australian Weather and Climate Research, a partnership between CSIRO and the Bureau of Meteorology, said: "Perhaps surprisingly, inclusion of northern hemisphere aerosols may be important for accurate modelling of Australian climate change." Aerosols come from many different sources. Sulphur is released when we burn coal and oil. More dust, also an aerosol, circulates in the atmosphere when land is cleared, burned or overgrazed. Some aerosols occur naturally like sea spray and volcanic emissions, but NASA estimates ten percent of the total aerosols in the atmosphere are caused by people. Most of this ten percent is in the northern hemisphere. European researchers also attending the conference will discuss a new forecasting service that will identify in unprecedented detail where these aerosols are coming from and where they are going. The new service, part of Europe's Global Monitoring for Environment and Security (GMES) initiative, will give global information on how pollutants move around the world across oceans and continents, and will refine estimates of their sources and sinks. Dr Adrian Simmons from the European Centre for Medium-Range Weather Forecasts, which is coordinating the multi-institution initiative, says: "The service will give much more detailed forecast information on air quality over Europe and provide the basis for better health advice across Europe and beyond". The service has clear implications for environmental policy and legislation. The five-day conference, organised by the Global Energy and Water Cycle Experiment (GEWEX) and the Integrated Land Ecosystem-Atmosphere Processes Study (iLEAPS) and locally hosted by Monash University, brings together many of the world's leading experts to discuss the important processes that govern water availability and drought and their role in present and future climate and global change. Professor Christian Jakob, who holds the Chair for Climate Modelling at Monash University and who chairs the local organising committee for the conference says: "It is fantastic to have attracted more than 350 researchers from more than 15 countries to come to Australia to discuss these very timely issues with us here in Melbourne." "The exchanges of energy, carbon and water between the land, ocean and atmosphere are of utmost importance to current and future climate. The fundamental role of the land surface, clouds, aerosols and of course rainfall for climate has been highlighted many times in the reports of the Intergovernmental Panel on Climate Change (IPCC). This conference will advance our knowledge in all these important areas by bringing world-leading experts together for a week of discussions. It has been a great privilege for me and Monash University to host this event," he added. The conference brings together the work of two major international research projects: GEWEX and iLEAPS. These projects complement each other and collaborate in a variety of global-change and climate-change research. Royal Swedish Academy of Sciences |
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| Related Aerosols Current Events and Aerosols News Articles Climate studies to benefit from 12 years of satellite aerosol data Aerosols, very small particles suspended in the air, play an important role in the global climate balance and in regulating climate change. Interactions with aerosols boost warming potential of some gases For decades, climate scientists have worked to identify and measure key substances -- notably greenhouse gases and aerosol particles -- that affect Earth's climate. Do dust particles curb climate change? A knowledge gap exists in the area of climate research: for decades, scientists have been asking themselves whether, and to what extent man-made aerosols, that is, dust particles suspended in the atmosphere, enlarge the cloud cover and thus curb climate warming. Ozone layer depletion levelling off By merging more than a decade of atmospheric data from European satellites, scientists have compiled a homogeneous long-term ozone record that allows them to monitor total ozone trends on a global scale - and the findings look promising. The greenhouse gas that saved the world When Planet Earth was just cooling down from its fiery creation, the sun was faint and young. So faint that it should not have been able to keep the oceans of earth from freezing. But fortunately for the creation of life, water was kept liquid on our young planet. The Sky Is Not Falling: Pollution in eastern China cuts light, useful rainfall New research shows that air pollution in eastern China has reduced the amount of light rainfall over the past 50 years and decreased by 23 percent the number of days of light rain in the eastern half of the country. Missing Link to Cloud Formation Found New chemical research shows how cloud seedlings form over forested areas. Scientists expect wildfires to increase as climate warms in the coming decades As the climate warms in the coming decades, atmospheric scientists at Harvard's School of Engineering and Applied Sciences (SEAS) and their colleagues expect that the frequency of wildfires will increase in many regions. Jupiter pummeled, leaving bruise the size of the Pacific Ocean Something slammed into Jupiter in the last few days, creating a dark bruise about the size of the Pacific Ocean. World's largest aerosol sensing network has leafy origins Twenty years ago, Brent Holben was part of a NASA team studying vegetation from space. In an unlikely career twist, his research morphed into the study of a critical, if overlooked, subplot in the story of climate change. More Aerosols Current Events and Aerosols News Articles |
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