Fig. 1: Muskox Valley. Oblique aerial photograph of Muskox Valley showing a polygon-controlled stream channel.
From: High Arctic channel incision modulated by climate change and the emergence of polygonal ground
The full valley is 8 km long and 1 km wide and has a flattened U-shape. Oblique image taken by authors looking up the valley toward a lake near the drainage divide. The dashed white outlined area shows the approximate limits of high-resolution three-dimensional LiDAR data collected in July 2019 (“Methods”). Oblique image center coordinates: 8872800, 457600, UTM projection, Zone 16. Inset oblique low-altitude images illustrate channelization characteristics of the valley floor. The inset images were taken by the authors and are color-keyed with arrows pointing to the location and showing the general camera orientation of the photographs. The noted polygon length scale in the second-from-left inset image is consistent between the four images. The inset plot in the upper right shows average land surface air temperature (SAT) anomalies in degrees Celsius for the entire globe, the northern hemisphere and in the western hemisphere for latitudes from 55 to 90°N, and longitudes from −165 to 0°, including the 75th percentile SAT. CRUTEM5 alternative grid dataset, www.cru.uea.ac.uk/cru/data/temperature42. Trend lines are calculated using the Savgol Filter, SciPy library, with window size of 25 and a polynomial order of 2. Satellite image sources for upper left inset image: Esri | Maxar (DigitalGlobe) | GeoEye | Earthstar Geographics | CNES/Airbus DS | USDA |USGS | AeroGRID | IGN | IGP | | AEX | Getmapping | swisstopo | GIS User Community, Imagery ID: 10df2279f9684e4a9f6a7f08febac2a9.
