active layer

American  

noun

1. (in Arctic or subarctic regions) the layer of soil, above the permafrost, that thaws during the summer.

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Example Sentences

As the Arctic warms, the active layer is getting thicker, and Rawlins wanted to know how that thickening, combined with warming and an intensified water cycle, would affect the terrestrial Arctic environment.

From Science Daily • Mar. 5, 2024

In aspect ratio phase trapping, defects, as well as the undesirable hexagonal phase, are "trapped" inside the grooves so that the surface of the active layer is a perfect cubic-phase material.

From Science Daily • Jan. 23, 2024

Permafrost still covers 85 percent of the state, but “almost everywhere, the depth of the active layer is increasing over the last few decades,” said Thoman.

From Slate • Mar. 11, 2015

This sequence of steps is affected by the morphology of the active layer.

From Nature • Aug. 15, 2012

Because the frozen permafrost was just a half meter beneath the active layer of soil, all the water on the tundra stayed near the surface.

From "Two Degrees" by Alan Gratz