Additional Global Research ProjectsThe Subtleties of Human Impacts
As scientists unravel the forces that affect climate, they are finding that human activities like forest clearing and urban expansion can have profound impacts. Altered land and water surfaces have particular interactions with the atmosphere, changing the balance of gases and particles while affecting the proportion of sunlight reflected back into space.
NCAR is working with scientists worldwide through the International Geosphere-Biosphere Programme (IGBP) to better coordinate research on the interrelationships between human activities; cycles of water, energy, and matter; and the climate system. To this end, NCAR will begin hosting a new IGBP project in 2005: Analysis, Integration and Modeling of the Earth System.
AIMES projects will consider the impacts of such alterations as land use changes on climate and, in turn, the impacts of changing climate on ecosystems. AIMES will also focus on the interactions between regional and global climate change, combining results from field programs in places such as the Amazon and the Arctic with global computer models.
Oceans play a major role in the global climate system. (Photo by Carlye Calvin.)
Scientists from more than 60 nations are working together in an unprecedented effort to track the interactions between the oceans and the atmosphere and to decipher their effect on Earth’s overall climate system.
The Climate Variability and Predictability Study (CLIVAR) is “perhaps the largest, most comprehensive international climate research program ever undertaken,” according to NCAR’s Kevin Trenberth, a past co-chair of the CLIVAR scientific steering group. Trenberth and several other NCAR researchers play key roles in the program, meeting with colleagues in the United States and abroad to chart an international agenda for climate research.
CLIVAR researchers study the role of the oceans in the climate system and evaluate computer models of climate change. The 15-year effort, which runs through 2013, aims to enhance scientists’ ability to predict climate on both global and regional scales, from a season to a century. Seasonal predictions might warn Kenyan farmers of heavy El Niño-related rains that could drown crops, alert towns along the western Atlantic coast of the projected intensity of the brewing hurricane season as La Niña builds in the Pacific, or caution Indonesian brush burners of an expected drought that increases the risk of wildfire.
CLIVAR is part of the World Climate Research Programme, which is sponsored by the World Meteorological Organization, the International Council for Science, and the Intergovernmental Oceanographic Commission.
The stratosphere, which lies just above the lowest layer of the atmosphere (the troposphere), plays an important role in the global climate system. Not only does it affect sunlight, clouds, and chemicals in the atmosphere, but the loss of stratospheric ozone is also causing it to cool, thereby mitigating global warming somewhat.
To improve our understanding of this important atmospheric region, scientists across the world have created an umbrella group, known as Stratospheric Processes and their Role in Climate. SPARC coordinates stratospheric research as a project of the World Climate Research Program.
NCAR scientist William Randel has been a key figure in SPARC since the project’s inception in 1992. Working with dozens of scientists in other countries, he has contributed to research into ozone and water vapor levels in the stratosphere, as well as assessed how well computer models are simulating stratospheric variability and change.
Now Randel is leading a major initiative within SPARC to improve predictions of future changes in the stratosphere. This initiative—Detection, Attribution and Prediction of Stratospheric Change—will involve studying worldwide data on past changes and correlating them with events such as volcanic eruptions and variations in energy output from the Sun. The goal is to integrate such information into global computer models and better anticipate future climate changes.
Water’s Mysteries
Scientists are trying to decipher the complex impacts of water on the atmosphere. (Photo by Carlye Calvin.)
Why do some clouds release torrential rain while others simply dissipate? How do families of thunderstorms in the tropics affect weather systems in the midlatitudes? Is it possible to reduce the uncertainty in weather and climate predictions stemming from the three states of water in cloud systems (vapor, liquid, and ice) and the transitions among them?
To tackle such questions, scientists from across the world formed the Global Energy and Water Cycle Experiment (GEWEX). In addition to studying the impact of water on temperatures, storms, and long-term climate trends, they examine the ebb and flow of water resources, which is a key concern for societies.
Through better understanding of the water cycle, forecasters may improve predictions of the location and intensity of storms. The research may also help scientists determine with more confidence the extent that global temperatures may rise in coming decades, since clouds affect the amount of warming at the ground and in the atmosphere by interacting with sunlight.
NCAR scientist Mitchell Moncrieff helped organize GEWEX under the auspices of the World Climate Research Programme. He and other cloud experts at NCAR are working with colleagues at Australia’s Bureau of Meteorology Research Centre, the United Kingdom’s Met Office, and other international institutions to better understand clouds and improve predictions. Their work, part of the GEWEX Cloud System Study, relies on observations from satellite, surface, and aircraft instruments worldwide as well as state-of-the-art computer models.
Global Collaborations
The Subtleties of Human Impacts
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