Scientists to Preview New Climate Change Research at AGU
BOULDER—As atmospheric scientists build on this year's reports by the Intergovernmental Panel on Climate Change, they are researching such issues as
Several climate scientists from the National Center for Atmospheric Research (NCAR) will discuss preliminary research findings at the annual meeting of the American Geophysical Union (AGU), which runs from Monday, December 10, through Friday, December 14, in San Francisco. NCAR's climate research is funded largely by the National Science Foundation, NCAR's primary sponsor, and also supported by the Department of Energy, NASA, and other agencies.
Reporters who cannot attend the meeting may contact David Hosansky or Rachael Drummond in the NCAR media office (see contacts, above) to learn more about the research.
Here are brief summaries of key presentations.
Storm Track Analysis from CCSM3: Present and Future Climate
Computer model analyses using the NCAR-based Community Climate System Model (CCSM) indicate that strong winter storms are likely to follow different tracks this century because of climate change. If society continues a business-as-usual approach to emitting greenhouse gases, preliminary research findings show that the U.S. West Coast is likely to see an increase in powerful winter storms, whereas Alaska will see a decrease. Atlantic storms are likely to shift north, with an increase in storm frequency from the Great Lakes to Quebec and a decrease along the U.S. East Coast.
The Role of the Nitrogen Cycle in the Climate System
Scientists are stepping up research on the role of nitrogen in the climate system, and they are beginning to incorporate the nitrogen cycle in computer models. This talk will preview new directions in nitrogen research. Nitrogen has a direct impact on climate change, because it both affects the ability of plants to absorb carbon dioxide from the atmosphere and influences atmospheric methane concentrations. Nitrogen also has implications for air quality because nitric oxide is a necessary precursor for ozone formation.
Modeling permafrost and permafrost-related climate change feedbacks in a GCM: Sensitivity to soil column depth and representation of soil organic matter
An important question for climate scientists is the likely impact of climate change on permafrost, the perpetually frozen soil in higher latitudes. Changes to permafrost can have significant impacts on Arctic ecology, hydrology, and biogeochemical cycling. New computer modeling shows how a more detailed representation of soil properties affects predictions of near-surface permafrost degradation. Revised 21st century soil temperature projections indicate substantial and widespread warming, raising concern that previously locked-up soil carbon could be released as carbon dioxide or methane.
Mechanisms for the Acceleration of the Brewer-Dobson Circulation in a Climate Change Scenario
New computer modeling shows that the buildup of greenhouse gases is accelerating the movement of air in the stratosphere. The change in the stratospheric Brewer-Dobson circulation, which moves air between the tropics and the high latitudes, is driven by enhanced dissipation of waves in the lower stratosphere. While the changes in the stratosphere are not expected to have a direct impact on society, the research illuminates the extent to which climate change is affecting the entire Earth system.
Using A-Train observations to constrain and improve Arctic cloud parameterizations
Scientists studying this summer's record melt of Arctic sea ice are using two new satellite instruments to analyze cloud cover in the region. Spaceborne radar and lidar data indicate that total cloud cover over the western Arctic, where most of the ice loss occurred, was significantly less during the 2007 melt season than the 2006 melt season. The additional solar radiation that reached the surface could have been enough to significantly warm Arctic waters and melt large amounts of ice that were already thinned by recent years of unusual warmth. The reduced cloudiness and increased solar radiation can be attributed to high pressure, low humidity, and unusually warm temperatures, associated with an anti-cyclonic summer circulation in the area.
The Impact of Cloud Seeding of Marine Stratocumulus on the Ocean Atmosphere System
Scientists are examining possible geoengineering approaches to counteract global warming, including spraying salt droplets into marine stratocumulus clouds. The droplets would make the clouds whiter, causing them to reflect more sunlight into space and thereby artificially cool the planet. This talk will present preliminary computer model results analyzing the impacts of such a plan on Earth's climate system.
NARCCAP - First Analyses Concerning the Snow Regime of the Upper Colorado River Basin
This poster presentation focuses on preliminary analyses of snowpack in the Rocky Mountains and how climate change will affect the availability of fresh water for people who depend on the Colorado River. The fine-grained analyses are made possible by a new research initiative, the North American Regional Climate Change Program (NARCCAP), which uses high-resolution computer models to study climate change in vulnerable areas of North America. The goal of NARCCAP is to zoom in on specific regions, thereby helping society prepare for the impacts of a changing climate.
The University Corporation for Atmospheric Research manages the National Center for Atmospheric Research under sponsorship by the National Science Foundation. Any opinions, findings and conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.