Researchers have developed a remote sensing method of measuring the depth of permafrost by analyzing vegetation cover in boreal ecosystems.

But in boreal regions, which harbor a significant portion of the world’s permafrost, obscuring vegetation can stymy even the most advanced remote sensing technology.

In a study published in January, researchers in Germany and at the University of Alaska Fairbanks’ Geophysical Institute developed a method of using satellite imagery to measure the depth of thaw directly above permafrost in boreal ecosystems. Rather than trying to peer past vegetation, they propose a unique solution that uses variations in forest color to infer the depth of permafrost beneath.

The forest for the trees

Permafrost deposits in the northern hemisphere have been continuously frozen for hundreds of thousands of years. The soil layer directly above that of permafrost, however, is much more dynamic — freezing and thawing with the seasons and growing or shrinking as it interacts with different types of vegetation at the surface.

Because permafrost in boreal regions is often overlaid with thick forest cover, typical methods of measuring permafrost and the active layer that work well in tundra regions — like using pulsed lasers or radar that penetrate the soil — are ineffective and can give spurious results.

Story Source:
Materials provided by University of Alaska Fairbanks. Original written by Jerald Pinson. Note: Content may be edited for style and length.