Eric A. Miller, Benjamin M. Jones, Carson A. Baughman, Randi R. Jandt, Jennifer L. Jenkins, and David A. Yokel
Relatively few fires have burned in the tundra of the Arctic Slope north of the Brooks Range in Alaska, USA. A total of 90 fires between 1969 and 2022 are known. Since fire has been rare, old burns can be found by the traces of thermokarst and distinct vegetation they leave in otherwise uniform tundra which are visible in archives of aerial photographs. Several prehistoric tundra burns have been found in this way. Detection of tundra fires in this sparsely populated, remote area has been historically inconsistent and opportunistic, relying on reports by aircraft pilots. Fire reports have been logged into an administrative database which necessarily has been used to scientifically evaluate changes in the fire regime. To improve the consistency of the record, we completed a systematic search of Landsat Collection 2 for the Brooks Range Foothills ecoregion over the period 1972-2022 and found 58 unrecorded tundra burns, about 42% of the total, which now numbers 139. Only 16 and 33% of all fires appear in MODIS and VIIRS satellite-borne thermal anomaly products, respectively. The fire frequency in the first 37 years of the record is 0.89 y−1 for natural ignitions that spread ≥10 ha. Frequency in the last 13 years is 2.6 y−1, indicating a nearly three-fold increase in fire frequency.
The webinar will be recorded and archived for later viewing.