The Arctic, the icy crown of the Earth, is experiencing an unprecedented climate crisis. It heats up incredibly quickly; four times faster than the rest of our planet. Sandia researchers are pulling back the curtain on the decrease in sunlight reflectance, or albedo, that is causing the Arctic to warm.

Scientists do not have parks and shovels. Instead, they used data from GPS satellite radiometers that capture sunlight reflected from the North Pole. This data dive could be the key to cracking the Arctic reinforcement code. His work was published in the journal Scientific Reports.

“Uneven warming in the Arctic is of scientific interest and current concern, leading us to question why this landscape is changing so dramatically,” said Sandia atmospheric and climatologist Erika Resler.

Previous studies have shown that sea ice albedo feedback likely contributes to strengthening in the Arctic. These albedo feedbacks can be divided into two main areas. First, there is a general decrease in sea ice, resulting in greater influence of the dark ocean absorbing more sunlight from the snow-covered ice, and temperatures are rising. A second factor is the reflectivity of the remaining sea ice, or local albedo, which includes water in ice pools due to melting.

Sandia researchers aimed to better understand the diminishing reflectivity in the Arctic. Senior Scientist Phil Drake worked with the U.S. Space Force to obtain permission for Sandia to analyze previously unpublished data from radiometers on GPS satellites.

“New observational climate datasets are unique. To be considered a climate dataset, observations must span many years. Small-scale science projects typically don’t last that long, making this dataset particularly valuable.” said Resler.

Amy Kaczmarowski, an engineer at Sandia, analyzed data from 2014-2019.

“There have been many local measurements and theoretical discussions about the impact of waterlogging on ice albedo. This study is one of the first comprehensive studies of annual effects in the Arctic region,” said Kaczmarovsky.

“Analysis of Sandia data found a 20-35% reduction in total reflectance during the Arctic summer. According to microwave measurements of sea ice collected during the same period, one-third of this reflectance loss is due to complete melting of the ice.”

The other two-thirds of the reflectance loss is likely due to erosion of remaining sea ice. “The most important discovery here is how much eroded ice reduces reflection,” Kaczmarovsky added. Weathered ice belongs to the rest of the sea ice, which may be thinner and contain melt ponds.

GPS satellites are expected to continue providing data until 2040. Sandia researchers hope other researchers will take their findings into account and incorporate them into their Arctic amplification models. They plan to continue taking GPS data and are excited to collaborate with other climate researchers for further analysis.

“We will continue to use this data to examine different regions of the world for climate applications,” Kaczmarowski said.