Atmospheric

Three hundred million years ago, Earth's climate shifted dramatically from icehouse to hothouse, with major environmental consequences. That shift was the result of both rising atmospheric carbon dioxide concentrations and the melting of vast ice sheets, new research by University of Michigan paleoclimatologist Christopher Poulsen shows.

Poulsen will discuss his findings in a symposium titled "Geosystems: Climate Lessons from Earth's Last Great Icehouse" at the annual meeting of the American Association for the Advancement of Science in San Francisco.

The changes occurred during the period of Earth's history when the continents were consolidated into a single supercontinent, Pangaea.

For the first time, NASA scientists have used a shrewd spaceborne detective to track the origin and movement of water vapor throughout Earth's atmosphere. This perspective is vital to improve the understanding of Earth's water cycle and its role in weather and climate.

For the first time, NASA scientists have used a shrewd spaceborne detective to track the origin and movement of water vapor throughout Earth's atmosphere. This perspective is vital to improve the understanding of Earth's water cycle and its role in weather and climate.


This view depicts the distribution of "heavy" and "light" water vapor molecules over Earth's tropics.

When a small pebble drops into a serene pool of water, it causes a ripple in the water in every direction, even disturbing distant still waters. NASA researchers have found a similar process at work in the atmosphere: tiny particles in the air called aerosols can cause a rippling effect on the climate thousands of miles away from their source region.


Dust from Africa's Saharan Desert lingers in high altitudes as it crosses the Atlantic Ocean. This picture was taken from an aircraft northeast of Barbados in 2006. Cumulus clouds can be seen poking through the tops of the dust layer, which is seen as a milky white haze. (Credit: NOAA)