Every year, there’s a recurring weak spot in the ice around Kotzebue, in an area known as Kobuk Lake. The weak spot is well known by locals, but its cause hasn’t been clear. Jiaxu Zhang is trying to fill in the gaps.
Zhang is the co-lead researcher on a project surveying sea ice from the air. She’s still working on an answer for why the crack develops, but she has a working theory that it has to do with where the ice forms at the beginning of the season.
Beyond understanding that one weak spot, Zhang said the research is important for developing models that will help both locals and the Arctic as a whole.
“This is a very new type of model which simulates each piece of the ice flow, like little polygons moving around,” Zhang said. “So, when I first saw that model, I said, ‘Oh, this is really cool. It can be really useful for coastal communities to get the sense of how the ice moves around.’”
The project is called Arctic AIR. The “AIR” stands for “airborne investigations and research.” Zhang’s team uses aircraft to conduct a variety of surveys — from looking at ocean color to determine potential algal blooms, to measuring sea ice using specialized cameras.
“What we want to do is to combine observation, modeling capabilities and also Indigenous knowledge, and try to develop a new ice model that can help predict the ice breakup timing,” Zhang said.
The study is a collaboration with the University of Washington, the National Oceanic and Atmospheric Administration, and local observers Alex Whitting, Bobby Schaeffer and Tyler Kramer. It is funded through NOAA’s Arctic Research Program.
Last month, Zhang's team conducted the surveys in a Twin Otter plane owned by NOAA. Nearly a dozen pieces of specialized instruments were positioned throughout the aircraft, including in a customizable floor bay, on the wings, and atop the fuselage.
One of the team’s primary tools is called the LATIS system, which pairs a LIDAR sensor with visual, infrared, and other imaging instruments. This integrated setup enables measurements of snow and ice thickness, surface temperature, and also captures video imagery during flight.
Another specialized tool is a hyperspectral camera, which can capture a range of data – less like a regular photograph and more in a block of images, with information undetectable to a human eye.
“If you look at something with your eye, you're looking at the visible band, and it's just like one picture,” Zhang said. “But for a hyperspectral camera, when it looks, it's like a whole spectrum including visible and near-infrared bands across all wavelengths.”
Zhang said the ideal time for researchers to monitor the ice is when it's moving around, and that they have to plan the trip several months in advance. This year, they arrived in mid-May — a little early for breakup, which started later than normal.
“We were looking back at the past 25 years from the satellite images, so this year is relatively late,” Zhang said. “It has been pretty late in the past two, three years in a row.”
Still, Zhang said her team was able to get information about ice features and terrain which can help improve their models for when they return next year. They also worked with several community members who shared their observations about weather and ice conditions.
“The purpose of this research is to provide some sea ice breakup forecasts for the community so it makes people safer to fish, to hunt over the ice,” said Zheng Liu, a research scientist on the project. “We really appreciate the community members who can provide some in situ data for us.”
He said he hopes the project will include more input from the local community, like ice measurements when people are out ice fishing.
The researchers said they hope to be back next year, to collect more data that hopefully can inform both locals and the scientific community about how and when the ice will break.
