Public Lectures Spring 2011


Sunday, March 6, 2011

antartica and its surrounding Oceans


>>Click HERE to view the video of this lecture.

Douglas Martinson, Ph.D.
Lamont Research Professor

A Delicate Balance: Antarctica and its Surrounding Oceans

 

Antarctica is surrounded by ocean waters that play a tremendous role in its climate. The world’s most powerful current circulates around the Antarctic, preventing warm subtropical surface waters from reaching the coast of the continent, thus perpetuating its glacial state. At the same time, the circulation of global oceans brings deep waters to the edge of Antarctica. These deep waters have been warming strongly over the last 50 years, disrupting the balance between the ocean and the continent. Recent Antarctic expeditions have provided data allowing scientists to estimate the important implications of this disruption.

 


 

Sunday, March 13, 2011

Currents, Conveyors, and Climate Change

>>Click HERE to view the video of this lecture.

Neil Pederson, Ph.D.
Lamont Assistant Research Professor

 

Ancient Trees Reveal Environmental Histories

Evidence from old-growth trees and ancient timbers recov­ered from homes and barns in the eastern U.S. and Hudson Valley region suggests that the climate and ecology of the previous four centuries may not have been as temperate as once thought. Using dendrochronology, or tree ring analysis, researchers at Lamont-Doherty now see that great droughts have sculpted current old-growth forests. Significant insight has been achieved through the use of certain trees, like the tulip poplar, which provide much longer records than previ­ously thought. Though climate in this region is characteris­tically humid and temperate, research suggests that water availability is an important driver of forest dynamics.

 

 


     

Sunday, March 27, 2011

Dust in the Wind: Dust, Stardust, and Earth’s Climate System

>>Click HERE to view a video of this lecture.


Andrew Juhl, Ph.D., Lamont Associate Research Professor; Gregory O’Mullan, Ph.D., Adjunct Associate Research Scientist; John Lipsdcomb, Riverkeeper Boat Captain

Hudson River: A Swimmable Future?*


Since the passing of the Clean Water Act, New York has made significant investments in wastewater treatment infrastructure and watershed management along the Hudson River estuary, leading to measurable improvements in water quality and ecosystem health. As water quality has improved, demand for public access and recreation on the river has also increased. O’Mullan and Juhl’s water sampling has shown, however, that intermittent sewage contamination persists throughout the estuary. Along with their colleague John Lipscomb, they will discuss findings from the Hudson River Estuary Program, including potential challenges and opportunities for improved management over the next decade.

*This lecture is sponsored by the Lamont-Doherty Alumni Association.

 

Sunday, April 3, 2011

 

Rockland County’s Water Resources

>>Click HERE to view a video of this lecture.

Natalie Boelman, Ph.D., Lamont Assistant Research Professor

Climate Change in Arctic Tundra: From Wildfire to Songbirds


The effect of rising summer air temperatures on Arctic flora and fauna may be particularly dramatic because of the low temperatures to which life has adapted in this region. In 2007, a vast and severe wildfire occurred in the Alaskan tundra—a characteristically wet ecosystem. The event was unprecedented, but as global warming continues, tundra fires of this magnitude may become increasingly common. Scientists make use of satellite imagery to understand the ecological consequences of such fires on these remote landscapes. Arctic warming also alters the timing of spring snowmelt and vegetation growth, triggering a cascade of changes that may impact the songbirds that winter in our backyards and migrate to the Alaskan tundra to breed every summer.