Monthly Archives: December 2012

NSIDC at AGU

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Photograph of Ira Flatow speaking at AGU

Ira Flatow, host of National Public Radio’s Talk of the Nation: Science Friday, spoke at the AGU Presidential Forum, reminding us why we need to communicate science clearly and effectively. Credit: Laura Naranjo

If NSIDC scientists are busy all year long conducting their own research, how do they keep up with what their colleagues elsewhere are doing? They exchange flurries of emails and phone calls, of course, and collaborate on journal articles and projects. But once a year, many of them are in the same place at the same time for the same reason: to attend the fall meeting of the American Geophysical Union (AGU). Whether you’re interested in glaciers or geoids, sea ice or plate tectonics, Earth or Mars, AGU is right up your alley. Each year, more than 20,000 scientists, students, and educators converge in San Francisco for the weeklong meeting. Many of NSIDC’s staff participate in the meeting as well, presenting talks and posters detailing their latest research, data, and success stories.

Collaboration and the cryosphere

The meeting turns out to be a great place to run into normally-distant colleagues and discuss your research or hatch future collaborations. Scientists and project managers from around the globe also take advantage of AGU to coordinate with each other in person, saving the time and expense of setting up a separate meeting. Town Hall meetings provide government agencies, academic programs, and special projects with a forum to gather input from AGU attendees and convey information, which helps funding agencies set their priorities. NSIDC’s booth is also a big draw at the exhibit hall, where we feature some of our most recent and popular products. Talking with hundreds of meeting attendees helps us determine what kinds of data people are looking for, and how we can help them find what they need to conduct their research.

The variety of opportunities at AGU also fosters numerous informal meetings, whether we’re mingling between talks or at events like the Cryosphere Reception. This is often where new ideas can foment that would never come up in the more formal structure of science talks or project meetings. It is also a place to discuss better ways to improve understanding of science by students and the public and to communicate the latest science news at media briefings.

Among the cryosphere sessions, Greenland’s dramatic summer melt was a hot topic, as was sea ice, the effects of atmospheric carbon, and thawing permafrost. This year’s Nye lecture, one of the cryospheric highlights of the meeting, featured Elizabeth Morris of the Scott Polar Research Institute. Her talk, “Hot ice and wondrous strange snow: three-phase mixtures or something more?” delved into the process behind the science, how researchers study things in the field and then make that information useful in broader scientific contexts. The Nye lecture is just one of several plenary lectures that touch on a variety of disciplines, such as oceans, volcanism, and atmospheres.

Something for everyone

Photograph of the first annual AGU Open Mic night

The first annual AGU Open Mic Night: Tall Tales and Earth Sonnets, hosted by cryospheric expert Richard Alley, drew a crowd from all disciplines. Credit: Laura Naranjo

No matter what your discipline, AGU has something for everyone. Award-winning journalist Ira Flatow, host of National Public Radio’s “Talk of the Nation: Science Friday” program, spoke at the AGU presidential forum. He reminded all of us why science—and communicating that science clearly—is more important than ever. And the first annual AGU Open Mic Night: Tall Tales and Earth Sonnets, hosted by cryosphere expert Richard Alley, was a stratospheric success. If you didn’t get there early enough to get a chair, it was standing-room only.

Even when science is conducted in a vacuum, it’s never really conducted in a vacuum. The energy and synergy of ideas that occurs at AGU keeps us coming back. We’ll see you next year.

 

 

References

American Geophysical Union (AGU) Fall Meeting Web site

AGU Video on Demand, including the Nye Lecture and the Presidential Forum featuring Ira Flatow’s talk

AGU ePosters

NSIDC science at AGU highlights Arctic sea ice, permafrost carbon, and Antarctic ice sheets

What caused last summer’s Greenland surface melt?

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Data image showing extreme Greenland surface melt in summer 2012

These satellite-derived maps show the extent of surface melt over Greenland’s ice sheet during the summer of 2012. On July 8, about 40 percent of the ice sheet had melted at or near the surface. By July 12, nearly 97 percent of the ice sheet surface had melted. High pressure ridges that persisted over Greenland created a lingering heat dome that caused the extensive melt. Credit: Nicolo E. DiGirolamo, SSAI/NASA GSFC, and Jesse Allen, NASA Earth Observatory

During the summer of 2012, scientists noticed something unusual in Greenland. On July 8, about 40 percent of the Greenland Ice Sheet surface showed signs of melting. But a mere four days later, 97 percent of the surface was melting, an extent that was unprecedented in the satellite record.

Just how unprecedented was this event? Does it mean that the Greenland Ice Sheet is possibly on the way out, like summer sea ice in the Arctic?

The Greenland block

To be clear, the Greenland Ice Sheet is still very much intact. It will take much more than a warm summer to melt ice that covers 660,000 square miles and averages 1.43 miles in thickness. And surface melt is quite shallow, including only the top several centimeters, according to Thomas Mote, a professor at the University of Georgia. Mote is one of many scientists studying Greenland’s ice, investigating what caused such a dramatic melt. Mote credits last summer’s extreme melt in large part to a weather pattern called the Greenland block. “Greenland blocking is a persistent high pressure ridging over Greenland,” Mote said. “That is when we will see warmer than normal conditions and more melt.” During a normal summer, about half of the ice sheet surface experiences melt. Last summer, this high-pressure block essentially parked over Greenland, creating a lasting dome of heat that rapidly melted nearly the entire ice sheet surface.

Melting in context

Photograph of researchers righting an instrument tower that is leaning due to melting ice

In 2004, researchers snowmobiled across part of the Greenland Ice Sheet to stabilize this weather station. The surrounding ice had slowly started to melt, causing the instruments to lean. Credit: John Maurer

Much of the media coverage cited a historical precedent for the melt, focusing on an ice core record from Summit Station, Greenland. This core indicated that such extreme melts are not unusual, and have occurred as frequently as every 150 years. But records from a single location, while invaluable, may oversimplify the history of such a vast ice sheet, and may not account for more recent changes in the broader environment surrounding Greenland.

“You’re talking about a single event at Summit that is quite remarkable but very short-lived, versus this sort of broad warming and increase in melt over much of Greenland,” Mote said. “The increased melt that we’ve seen in Greenland over the past several years is associated with the general warming across the Arctic.” Greenland experienced record warming in 1999, 2007, 2010, and in 2012, mirroring years in which the Arctic as a whole experienced warming, and often, record sea ice minimums.

Mote and others hope to place the extreme event into a larger environmental context, seeing how factors like air temperatures and winter accumulation might play a role. And in spite of the recent warming, Mote cites some positive evidence among the many questions that Arctic warming often raises. “There is some evidence recently that suggests that the Greenland Ice Sheet can recover more easily perhaps than we might have thought,” Mote said. “I think we’re still trying to get a sense of just how inter-related these different cryospheric measures are across the Arctic.”

Reference

Nghiem, S. V., D. K. Hall, T. L. Mote, M. Tedesco, M. R. Albert, K. Keegan, C. A. Shuman, N. E. DiGirolamo, and G. Neumann. 2012. The extreme melt across the Greenland ice sheet in 2012. Geophysical Research Letters, 39, L20502, doi:10.1029/2012GL053611.