News from the polar regions in June includes speculation on the future of the Arctic sea ice and permafrost, unexpected behavior of an Antarctic ice stream, and new technology designed to assist in polar research. Missed these stories the first time? Read on!

In May, we reported on an international, three-week expedition designed to validate the upcoming CryoSat-2 mission – a 2008 satellite study of the polar ice cover. In another validation program, Alain Hubert and Dixie Dansercoer endured a grueling, 106-day trek from Siberia to northern Greenland via the North Pole. En route, the explorers braved harsh temperatures, polar bear encounters, and the physical challenges of dragging sledges over ridges of compressed sea ice and across fractured ice in open water. The pair paused every 50 kilometers (31 miles) to take snow-depth measurements – data that will be used by the CryoSat team to determine how overlying snow can affect ice elevation measurements. Satellite data also played an important role in the explorers’ safety near the end of the trek, when the sea ice began to break up “chaotically” near the coast of northern Greenland.

During the summer of 2007, Arctic sea ice shrank to more than 30 percent below average, and fall air temperatures (August – October) were more than 4 degrees Fahrenheit warmer than normal. Researchers at the National Center for Atmospheric Research (NCAR) and the National Snow and Ice Data Center (NSIDC) wondered if these two phenomena were related, prompting a study of climate change simulations. Researchers have concluded that during periods of rapid sea-ice loss, Arctic land as far as 900 miles inland is warming 3.5 times faster than average. Accelerated warming translates into rapidly thawing permafrost, which may in turn lead to significant carbon dioxide or methane emissions. An important, unanswered question, according to lead author David Lawrence of NCAR, is “how the delicate balance of life in the Arctic will respond to such a rapid warming.”

Unfortunately, that rapid warming may be closer than we’d like. Many research teams have projected that the summer sea-ice minimum in 2008 will be equally or more dramatic as that of 2007. Independent assessments and explanations can be found on the Study of Environmental Arctic Change (SEARCH) web site. The National Snow and Ice Data Center’s Arctic Sea Ice News and Data Analysis page provides monthly updates and images on ice conditions across the region. 

Scientists continue to analyze ice cores to better understand past warming events and predict future climate change in the face of increasing anthropogenic greenhouse gases. Analysis of a two-mile-long Greenland ice core reveals two large temperature spikes in the Northern Hemisphere. Temperatures jumped 22 degrees Fahrenheit in just 50 years about 14,700 years ago, and then returned to ice age conditions before another abrupt warming about 11,700 years ago. Ice core data revealed that massive “reorganization” of atmospheric circulation coincided with these temperature spikes. According to Jim White, a researcher at the University of Colorado at Boulder, “Since such rapid climate change would challenge even the most modern societies to successfully adapt, knowing how these massive events start and evolve is one of the most pressing climate questions we need to answer.”

Also looking to the past is Professor Eske Willerslev of the University of Copenhagen. He and his colleagues have analyzed a hair sample from the Disco Bay ice fjord area of northwest Greenland, finding a mitochondrial DNA match to a population in the Aleutian Islands. This finding suggests that the maternal line of immigrants came to Greenland via Alaska and Canada approximately 4,500 years ago. No connection exists between this DNA and that of the Thule immigration, the ancestors of the modern Greenlandic Inuit. Willerslev hopes to eventually reconstruct the “core” genome from the hair and thus trace the paternal lineage of the immigrants.

In addition, the advent of the summer field season in the Arctic means a host of new studies. Starting June 29, NASA aircraft will be deployed to study the chemistry of the lower Arctic atmosphere, including the smoke plumes of northern-latitude forest fires. Researchers hope to examine these fires’ contribution to Arctic pollution and the implications for climate change. The Alaska Space Grant Program and the Arctic Amateur Radio Club’s Balloon Experiment and Research Program (B.E.A.R) launched its first balloon on May 10, capturing more than 100 photos and videos. As the program expands, it will allow University of Alaska Fairbanks students to conduct atmospheric research of their own.

In Antarctica, paleontologists have discovered fossilized burrows of tetrapods (land vertebrates with four legs or leg-like appendages). The cast fossils date from the Early Triassic epoch, about 245 million years ago, a time when Antarctica was connected to South Africa in the supercontinent Pangea. These burrows predate previous finds of tetrapod bones in Victoria Land, Antarctica, by at least 15 million years. Though Antarctica was ice free at the time the burrows were dug, the temperatures would have still been quite cold, making the burrows necessary for the animals’ protection from the elements.

Seismological and GPS analyses of an Antarctic ice stream (a giant glacier 60 miles wide and one-half mile thick) revealed unexpected behavior. The ice moves about 18 inches over a ten-minute period, remains still for 12 hours, and then moves another 18 inches. As the ice stream moves, it emits seismic waves detected as far away as Australia and equivalent to a magnitude 7 earthquake. While glaciologists had believed that glaciers moved continuously by creep, this data indicates a “stick-slip” pattern of movement, the classic motion of earthquakes. The difference? The timing of the movement. While the “stick-slip” of an earthquake happens very rapidly, a glacier’s movement lasts much longer (in this case, a ten-minute period). Researchers hope that this phenomenon may provide clues to changes in the movement of ice streams of the West Antarctic Ice Sheet as this portion of the continent warms.

Such warming caused a large area (400 square kilometers, or 154 square miles) to break off from the Wilkins Ice Shelf on the Antarctic Peninsula in March. Now, despite the winter season’s colder temperatures, the shelf has experienced further break-up, with an area of about 160 square kilometers (61 square miles) breaking off in late May. Satellite images show a dwindling strip of ice, 2.7 kilometers (over 1 ½ miles) wide, that is protecting thousands of kilometers of the ice shelf from disintegration. Researchers believe that further break-up is very likely. Unlike the eastern portion of the continent, the Antarctic Peninsula has warmed in the past 50 years. In the past 20 years, seven ice shelves along the peninsula have either retreated or disintegrated, including the Larsen B Ice Shelf in 2002.

Finally, new technology will assist polar scientists in their efforts in the Arctic and Antarctica. New medical equipment will help researchers understand how the human body adapts to the physically challenging environment of Antarctica – and possibly help prepare for future missions to Mars. A new wireless sensor network will allow researchers to collect data and monitor environmental factors from a distance, enabling otherwise difficult or even impossible studies such as Arctic ice cap movements. And new robots called SnoMotes will traverse potentially dangerous ice sheets, allowing researchers to collect data while avoiding dangers posed by the cracking and shifting ice.

Know of another significant news story from June that you’d like to share? Reactions to one of the stories discussed here? Post a comment – we’d love to hear from you!