It represents annual permafrost warming, build with data from ESA Permafrost Climate Change Initiative (Permafrost_cci): Permafrost Ground Temperature for the Northern Hemisphere, v3.0. It was my entry to the European Space Agency little picture competition 2023, a call to “transform decades of satellite and climate data to compelling, impactful Little Pictures“.

I squeezed in hours during a weekend to envision it, plan it, refresh R, refresh .nc format files, and style it. It also involved some re-reading on permafrost warming, just to be sure I was going for the correct gist. Have you ever seen aerial pictures of tundra? Beautiful! My figure does aspire to look like that but I build it as an evocative abstraction.

Nerdish details:
–I had worked with permafrost (visually) before, so I found it an easy data to interpret, also I wanted to avoid using the ready-made data sets that ESA provided to the participants.
–The shapes representing the years are tessellated same-area irregular hexagons. These irregular shapes are reminiscent of the permafrost polygonal landscape.
–The colour of the background is reminiscent of a high organic matter soil. Could have been darker.
–The temperature time-series is shown in several channels, scaled within the max-min values of the series:
–  color of middle polygons: pale blue-pink (“cold” ice -“hot” ice)
–  color of foreground polygons green-yellowish (moist-dry)
– scale of the foreground polygons big-small (structured-unstructured). So small for the last years that it does not show.
–Based on the pale blue colour, the rest were decided based on complementarity, contrast, and readability.
–Small text for start and end year are placed to help understand the reading direction of the series.