Xuelong sets up record number of Arctic ice stations

Chinese research vessel Xuelong completed ice station survey operations at 12 sites during the country's 16th Arctic expedition, setting a record for the largest number of ice stations established by a single vessel in China's Arctic missions, according to the Ministry of Natural Resources.

The ice station operations began on July 25 and lasted 14 days. All 12 sites were located at latitudes north of 82 degrees and selected for thicker sea ice to ensure that unmanned instruments could remain operational through the summer melt season. More than 30 ice-based buoys of various types were deployed across the sites.

The operations involved integrated observations across multiple disciplines, including the atmospheric boundary layer, sea ice physics, sub-ice ecology and sub-ice ocean dynamics. The data will provide in situ, long-term observations and validation for research into the evolution of the coupled atmosphere-sea ice-ocean system amid the rapid decline of Arctic sea ice.

The 12-station network enables coordinated monitoring at multiple points, which is expected to improve understanding of the mechanisms driving rapid changes in the Arctic and enhance the accuracy of climate predictions. Xuelong 2 will establish about seven additional ice stations later in the expedition to further expand observational coverage.

During the operations, scientists used ice core drills and chainsaws to extract a block of sea ice measuring 1.3 meters thick and 1.2 meters on each side. The sample will be used to measure the mechanical properties of sea ice under Arctic conditions and further enrich the Arctic sea ice sample database.

"The mechanical properties of sea ice determine its strength," Sun Kai, an expedition member, told China Central Television. He said understanding ice mechanics is essential for ship design, as encountering particularly hard ice in ice-covered waters can impede a vessel's progress and cause structural damage.

The team also established an unmanned observation network in the Arctic Ocean and tested domestically produced marine observation equipment for operational application.

"This year's specialized tasks are particularly demanding," Qu Meng, leader of the sea ice team, told CCTV.

"The hydrology group has more than a dozen ice-based ocean profiling buoys, so we set up 12 ice stations to carry out array monitoring with these buoys," Qu said.

Among the most widely deployed instruments — ice-based shallow-water profiling buoys, ice-based deep-water profiling buoys and sea ice drift buoys — domestically produced equipment accounted for more than 90 percent on average. This level of domestic capability, combined with mature technologies, enabled the large-scale array deployment and automated networked monitoring achieved during the expedition.

"We've gradually moved from the simplest instruments, such as sea ice drift buoys and mass-balance buoys, to ecological unmanned ice stations. The range of domestically produced equipment will only keep growing," He Jianfeng, the expedition's chief scientist, told CCTV.

An ecological unmanned ice station, deployed for the first time in the Arctic, is expected to provide new insights into how organisms beneath the ice survive the polar night and respond to the polar day.

"The system uses integrated acoustic, optical and electrical sensing to carry out long-term, continuous observations of the atmosphere, ice, sea and ecology beneath the ice in the central Arctic," An Baobao, an expedition member, told CCTV.

An said this is the first time such acoustic-optical-electrical data collection has been conducted in the shallow subsurface layer beneath polar ice.

limenghan@chinadaily.com.cn