New scientific mode
LARISSA represents one of the biggest IPY projects
Posted September 18, 2009
Ellen Mosley-Thompson doesn’t exaggerate when asked about how the scope and complexity of the LARISSA program compares to other polar fieldwork she has undertaken over a career that spans more than 30 years.
“This is the biggest project that I’ve worked on. I’ve never worked on anything of this magnitude,” said Mosley-Thompson, an ice-core and paleoclimate expert and professor at The Ohio State University. Mosley-Thompson, with her colleague and husband Lonnie Thompson, head an ice-core team that drills into ice caps from Greenland to the high-altitude ice fields of South American and Asia to the large ice sheets of Antarctica.
Her team’s role in the International Polar Year (IPY) project is to drill an ice core from a camp on an ice ridge about 2,000 meters above sea level — a seemingly pretty standard operation for scientists who have made dozens of expeditions to equally remote and much higher places in the world.
Yet drilling the core will be challenging, as it will be among the deepest cores their team has drilled — 400 to 500 meters long to bedrock. The Thompsons expect it to provide a highly detailed story about climate in the region over thousands of years and its possible connections to global events.
“The excitement is really going to be bringing our records together with what the other partners will have. We’ve never had that luxury,” Mosley-Thompson said.
Indeed, LARISSA brings together more than 30 scientists for one expedition, most of them based aboard the RVIB Nathaniel B. Palmer for two months, collecting numerous samples for oceanographic work, including deploying moorings in select locations around the Larsen Embayment to study how the ecosystem has changed since the Larsen B Ice Shelf collapsed in 2002.
“Things are flowing into place quite nicely,” said Eugene Domack, LARISSA principal investigator and chief scientist of the first of at least two science cruises for the project. “The complexity of the project demanded that we had a lot of lead-up time with planning. You just can’t throw this thing together in six months like a normal cruise.”
In addition to the shipboard work, two helicopters will operate off the ship, providing access to the eastern half of the Antarctic Peninsula, as well as the remaining bit of the Larsen B Ice Shelf and the glaciers that flow into it, for glaciological and geological fieldwork.
“Big is the word for LARISSA. We’re doing everything under the sun,” said Adam Jenkins, the LARISSA project manager for Raytheon Polar Services Co., the prime contractor to the National Science Foundation (NSF).
“We have an ROV. We’re coring four or five different ways. … Plus, full physical oceanography work. We’re going big with everything,” he said, adding that this is only the second time in more than 15 years of operation that the Palmer will support helicopter flights.
It’s Jenkins’ job to ensure all the moving parts of the project chug along smoothly, oiling the machine with as many contingency plans as possible. That task got easier when the NSF decided to support the Thompsons’ drill camp with a Twin Otter airplane from British Antarctic Survey’s Rothera Station on the western side of the peninsula.
“That was a huge deal,” Jenkins noted.
Still, even with the ship freed from helping the ice-core team, the scientists know they’ll need ideal conditions to accomplish all the work they want in 60 days.
“This is a very complicated program,” said Ted Scambos, lead scientist at the Boulder, Colo.-based National Snow and Ice Data Center, who will spend most of his time in helo-supported field camps setting up instruments to observe the ice shelf and glaciers.
“To have all of these different disciplines operate simultaneously from the Palmer is a real trick,” he said. “It’s a tribute to Raytheon, Eugene and other leads to organize this and to get it all fit together to be as active as we’re planning to be without getting in each other’s way.”
The good news is that because LARISSA is an integrated project, the scientists are all dependent on one another’s results, so each team has an appreciation for what the others are doing, according to Lisa Clough, current NSF program manager for the LARISSA project.
“Without a doubt this is a complicated logistic challenge, but when you hear the scientific interactions that have already taken place at planning meetings, on phone calls, and certainly the synergisms that will continue on the cruise and beyond, it’s worth it,” she noted.
Oceanographer Bruce Huber has worked in Antarctica for about three decades and has participated in other major ocean-going campaigns, including the 1992 Ice Station Weddell program with the Russians. That large, multi-disciplinary project put a science team on an ice floe that drifted along the western Weddell Sea taking measurements of the region.
“That was really the first time we got a comprehensive look at the oceanography along there,” he said.
While similar in scope to Ice Station Weddell, LARISSA is probably a “little more challenging perhaps because we’re trying to do so much from one platform,” Huber added. “I think therein lies the greatest challenge. We’re pushing the ship and the people on the ship to the absolute max, so everything has to be extremely well organized.”
Weather is the most obvious risk to the ambitious plan, particularly for flying the helicopters. There are also restraints on how the helos can operate even when the sun is shining, such as a range limit of 24 kilometers for flying over open water. “We’re very concerned about the weather to get everything done. By having two helicopters, with good weather and good conditions, we’re going full tilt,” Jenkins said.
Certain coring operations to collect seafloor sediments will also affect shipboard operations. Jenkins said the jumbo piston coring system will require a clear deck for safety reasons.
“That requires the helo deck be cleared because there’s a large turning block that we set on the deck to turn the cable for deploying that coring system,” he explained. “It’s a pretty dangerous, heavy, intensive operation.”
Other wild cards could come into play after the ship arrives at the site of the former ice shelf. Maria Vernet, a research biologist with Scripps Institution of Oceanography at UC San Diego, said sea ice could slow the expedition.
“This is a pretty high-risk approach in that we hope the sea ice is open enough so we can do the work we want,” Vernet said.
The Palmer is actually an icebreaker — and while there’s little chance the ship could become stuck a la Shackleton’s Endurance — thick sea ice will slow the ship and cause it to burn more fuel to forge a channel.
Said Scambos, “I’m not worried about getting trapped, but it may restrict what we can do. We’re planning like we can go anywhere we want, but we’ll see if that’s really the case.”
There is some good news on that front, according to Jenkins. He said sea ice conditions in the area are projected to be favorable when the Palmer arrives in January. “It’s been open water in a lot of that area and that’s kind of what we’re hoping for. But it could change,” he said.
A smooth trip and a successful science cruise for a project as large and complex as LARISSA will provide more than rich new datasets for this rapidly changing system, Mosley-Thompson noted.
“LARISSA is a very important project,” she said. “It’s imperative that we’re all successful individually, but it’s even more important that we’re collectively successful because this could be a new mode of scientific and logistical operation.”
NSF-funded research in this story: Eugene Domack, Hamilton College, Award No. 0732467; Arnold Gordon and Bruce Huber, Columbia University, Award No. 0732651; Ted Scambos, University of Colorado at Boulder, Award No. 0732921; Ellen Mosley-Thompson and Lonnie Thompson, Ohio State University, Award No. 0732655; Maria Vernet, University of California-San Diego Scripps Institution of Oceanography, Award No. 0732983.
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