Most mornings Chris Petrich’s biggest hurdle is staying off of the ski lift, which he passes on his way to work in the small town of Narvik in Northern Norway. But this German-born scientist (admirably) resists the temptation and continues to work at the Northern Research Institute (NORUT) Narvik, where he investigates the melting and breakup of Arctic ice. At NORUT, Petrich is the project manager of ColdTech, an initiative to develop sustainable Cold Climate technology. ColdTech is a multi-institutional research team led by NORUT Narvik, and funded by the NORDSATSING program of the Norwegian Research Council and eleven industry partners.
A future with less ice
Petrich's current research focuses on sea ice surrounding Svalbard, an archipelago in the Arctic north of Norway and in the Barents Sea, where oil exploration and vessel traffic can be significantly affected by sea ice. In addition, he studies the transition in ice conditions along the Northern Sea Route—the Arctic passage for sea traffic. The ability to predict how much ice will be where in the future will affect many industries and initiatives.
Alaskan training grounds
Arriving with experience in Antarctic sea ice, Petrich broadened his expertise during his time as a researcher at the University of Alaska, Fairbanks (UAF). There he studied the breakup of landfast ice in the Chukchi Sea together with UAF researcher Hajo Eicken, whose sea ice monitoring network, SIZONet, is funded by the U.S. National Science Foundation. The UAF group observes the ice via their own land-based radar, and up close in person by foot and boat. Based on this decade-long record of observations, Petrich developed a forecast of landfast ice breakup, distinguishing between the thermal and mechanical breakup of landfast ice. Solar radiation is the driving force behind thermal breakup of the ice. Mechanical breakup usually occurs as a result of large ice movement and/or ocean currents.
Looking beneath the ice surface
The key to understanding which process is dominant lies in the absence or presence of grounded pressure ridges. These ridges are large chunks of ice that become grounded, not unlike a ship on a sand bar, and essentially form a protective barrier between the near-shore landfast ice and the open ocean. When these ridges form, the landfast ice is mostly protected from the outside forces that would cause mechanical breakup and will breakup slowly with melting from solar radiation.
If the ridges are absent, the ice is more vulnerable to the outside forces responsible for mechanical breakup. During the ten-year study, every year grounded ridges were present, the ice breakup occurred later than when they were absent.
Culture based on ice
Understanding the timing and mechanics of ice breakup is critical for members of the local community of Barrow, who rely upon the ocean for food, as well as for maintaining their native cultural heritage. Native Alaskans fish and launch boats from the ice while it is still intact during the spring. Once the ice clears in summer, they are able to set the boats out directly from land, but must be on the lookout for drifting ice.
Knowing how and when the ice breaks up is not just important for planning, but for safety as well, since maneuvering boats and gear over melting ice can be very dangerous. Locals who rely upon the ice use data from the UAF SIZONet research team for information on ice breakup and movement, and in the modern digital age, this is possible like never before.
Petrich says, “There are people with their [smartphones] actually accessing real time data while they’re on the ice to get warning signs…if there’s a [floe] coming that might be very big and might impact onto the landfast ice and kick off a chunk.”
As the researchers provide information, the locals offer their own expertise, which Petrich says greatly enhances the effort.
“We use suggestions made by local experts, people who’ve been out hunting on the water for years…to tell us where to put our instruments…because sometimes you have very interesting phenomena, such as wind blowing from one direction, but ice actually drifting the opposite direction,” says Petrich. “And we follow their advice. We have a very close relationship there.”
This work on forecasting the breakup of landfast ice, and distinguishing between thermal and mechanical breakup, was published in the Journal of Geophysical Research in 2012. The implications for this study continue to pay off for Petrich in his new role in Norway.
Armed with a better understanding of the importance of grounded pressure ridges in ice mechanics, Petrich’s group at NORUT studies the impact of pressure ridges on structures in the ice, and on vessels traveling through icy seas. And as the local ice expert, Petrich is often asked to consult on unexpected projects. “I find myself involved in any project related to frozen material. Or thawing material. Once you know sea ice, anything else in the melting-freezing category is easy. Sea ice is quite a complex material. So in that sense I can put my sea ice background to good use here for industry, environmental, and offshore work.”
Results are still forthcoming, as Petrich’s role in this work is quite new. But from the breadth of his research, and excitement in his voice, Petrich is clearly a contender to become Norway’s new king of ice. —Bobby Reece