Aboard the ‘Snow Dragon’
UTSA geoscientist spent two months in the Arctic to study sea ice changes
On a 2008 expedition to the Arctic, Chinese investigators saw about 14 polar bears. However, on his first-time trip to the icy region for a research mission during the summer of 2010, Hongjie Xie saw only one. The lack of sightings of these magnificent bears roaming the frozen wasteland in search of food hinted at what Xie’s research ultimately confirmed: global warming is melting sea ice at a rapid rate and negatively impacting the Arctic’s inhabitants.
“We have found that sea ice is changing very fast in terms of thickness, concentration and area. It’s shrinking,” said Xie, UTSA associate professor of geological sciences. “Our ship was able to move a lot easier through open water because the concentration [of ice] is 60 to 80 percent. It should be 90 to 100 percent.”
"We were less than 100 miles from the North Pole because of the thinning of the sea ice."
Xie (pronounced “she”) was one of only two Americans invited by the Chinese government to spend two months aboard the vessel Xuelong, or “Snow Dragon,” as part of the Fourth Chinese Arctic Expedition to examine oceanice- atmosphere interaction and the marine ecosystem’s response to climate change in the region.
The professor, who represented the U.S. National Oceanic and Atmospheric Administration’s Sea Ice Outlook Program, was assigned the task of studying ice concentration, floe size, melt pond coverage, sea ice and snow thickness.
The purpose of his mission was to study how and why the sea ice has been melting so rapidly, and to help answer these questions: Does the sea ice retreat evenly everywhere or is it retreating faster in some areas than in others? Does the thinning of the sea ice always occur in the same way or do geographic factors influence the process?
The Chinese are interested in the mechanisms of sea ice melting, as well as its impact on the Arctic ecosystem and possible effects on the Chinese climate.
“The Chinese are extremely interested because they and others would be able to sail their cargo ships through the Arctic Ocean to North America and Europe with much reduced cost,” he said. “At the melting rate we are observing now, they may be able to do so in 30 to 50 years.
“With that said, an ice-free Arctic would open new trade routes and will benefit some countries and may help the economy for the regions, but in the long term it will cause environmental pollution and damage to the Arctic regions and ecosystem.”
As global warming accelerates and causes Arctic sea ice to melt and thin, Xie predicts the Arctic Ocean could be free of ice in the summer in the next 20 to 30 years even though sea ice will still cover the entire Arctic Ocean in the winter.
“I think an ice-free summer in the Arctic Ocean will be bad and will impact the current arctic ecosystem,” he said. “Polar bears, seals and walruses might have difficulty surviving. But other species from other areas might make this their new territory. An ice-less Arctic in the summer will further warm the nearby air and water and will make global warming even worse.”
Years ago, travelers could only get to the lowest Arctic latitudes in the summer, Xie added, but because the ice has melted so much, large ships can navigate into the higher latitudes.
On Xie’s trip, Xuelong traveled to 88.4 degrees latitude with no problems, the professor said. That is closer to the North Pole than San Antonio is to Dallas. A few years ago, this would not have been possible. The ship would have run into ice blocks three meters or more in thickness.
Xie, who oversees UTSA’s Laboratory for Remote Sensing and Geoinformatics, boarded the Xuelong on July 3 in Korea and set sail for the Arctic Ocean with 121 people, including 61 researchers, 54 crew members and six journalists. Five countries were represented including Estonia, Finland, France, Taiwan, and the United States.
Xie’s fact-finding duties involved using a variety of instruments to measure the changes of sea ice. He used an electromagnetic induction device to measure the thickness of the ice, as well as a spectroradiometer to measure the optical characteristics of the snow and ice on the surface of water. He also was in charge of a video camera attached to the ship that recorded images of sea ice changes every 10 to 15 seconds.
Xie and teammate Huajun Wang drill to measure the snow depth and ice thickness.
Walruses bask in the summer sun.
Xie and teammate Changqing Ke measure reflection power of snow and ice.
“We also did sea ice observations every 30 minutes,” he said. “We used this information to compare to and validate the accuracy of data collected by satellites.”
Xie said that data collected from the research mission will help him better interpret the satellite-derived data and develop better algorithms to convert satellite data to geophysical data. The results and experience will also help him write proposals so that he and students can continue their research.
“I am working on two papers based on the data collected there, and one Ph.D. student is processing data and will develop a dissertation topic,” Xie said. “We have submitted several proposals seeking further funding support. Corroborative data processing and interpretation and analysis with Chinese colleagues are underway.”
The geophysical data combined with satellite information will also be used to assist researchers around the globe gain a better understanding of Arctic and global climate change.
Xie offered one explanation for why the region’s sea ice is melting so rapidly.
“It’s a positive feedback system,” he said. “Sea ice melts both from the bottom up, due to increased ocean temperature, and from the top down. When that happens, the melted ice leaves more open water, which absorbs more solar radiation and raises the temperature of the water even more. The temperature increase causes even more ice to melt.”
He offered a grim outlook for the ice bears.
“Polar bears depend on ice to move around to hunt for seals and walruses, but if the ice is gone, they have no place to live or search for food to eat.
Although the recent mission was Xie’s first trip to the Arctic, he had been to Antarctica in 2006 on one of the research expeditions involving Stephen Ackley, UTSA research associate professor, and several graduate students.
Ackley, a sea ice scientist, has to date secured more than $1.5 million in funding from NASA’s Cryosphere Science Program and the National Science Foundation’s Office of Polar Programs for expeditions that offer students the rare opportunity to travel to the polar regions
Ackley explained that the college’s graduate students are doing research in applied geology or environmental science with a component of using remote sensing from space. The measurements taken in the field, from ships, and on the ice surface, provide the details on the physical properties of the snow and sea ice that affect the signals received in space. Then, satellite data from remote and inaccessible areas can be compared to physical data and correctly interpreted.
“Particularly, we want to characterize the changes that are ongoing in these recent times, which the students also are able to witness first-hand in these field trips.”
For Xie, living aboard the Snow Dragon from July 3 to Sept. 20 had its pros – and a couple of cons.
“I made a lot of new friends from different countries,” he said. “We will continue to collaborate and work on proposals for the National Science Foundation and NASA.”
The expedition had excellent hosts, Xie said, who took great care to ensure that their guests had ample opportunity for rest and recreation as they passed the time, when they weren’t busy working off-ship. Social activities included karaoke, basketball, ping-pong, card playing, and swimming in the ship’s indoor pool. Passengers even put their culinary skills to the test when they came together to make dumplings.
“We had lots of good Chinese food,” Xie said with a big smile, adding that he and his teammates even enjoyed an outdoor barbecue with lots of grilled fish and meat.
Presentations were organized, so that each scientist or researcher could report on his or her work and findings.
If there was one thing Xie would have liked, it would have been to spend more time outside for experiments. “We wanted to spend more time on research, but we had a schedule,” Xie said, adding that temperatures generally hovered around zero degrees, dangerous for prolonged exposure.
The researchers would go out at 9 a.m. for morning work and come back to the ship at noon for lunch. They would go back out from 1:30 to 4:30 p.m., and then return to the ship for the rest of day. “We could have done more, but the guides would tell us we had to go back to the ship because the polar bears might be getting near,” he said.
Guides with guns were charged with watching out for danger, so Xie and the rest of the researchers never were in fear of the polar bears while outside.
During the first few weeks in the Arctic Ocean, Xie’s sleep was often interrupted by the grinding noise of the Xuelong cutting through blocks of ice. “Our cabin was at the front of the ship,” Xie said, “but after a while I got used to it.”
A visit near the North Pole made the two-month sojourn well worth any small inconveniences for the professor, such as missing his sister’s June wedding in China that his wife and three children attended without him, or the mounds of paperwork that awaited him when he returned to UTSA.
“We were less than 100 miles from the North Pole because of the thinning of the sea ice,” Xie said. “Our ship probably could have continued to the North Pole, but then they thought we might not have enough fuel to return. Some flew there in the helicopter and placed the Chinese flag and the team flag there.
Xie, who has been on the faculty since 2004, earned a Ph.D. in remote sensing and geographic information systems from the University of Texas at El Paso in 2002.