Active layer is measured c. 400 m south of the runway on a south facing slope at an elevation of 11-22 m a.s.l. Vegetation changes from dry dryas heath at the upper end to a waterlogged Eriophorum fen in the lower end. The site consists of 208 measuring points in a 120 m x 150 m grid (16 almost N-S oriented rows each with 13 points. There are 10 m between every point. Active layer is measured manually using a metal rod. The dataset was iniated in 1996. Measurements are started as soon as the one point is free of snow in the grid. Measurements are repeated every week until only the snow fan on the south-facing slope is left, thereafter measurements are repeated every second week until the upper part of the soil starts to freeze.
