Scientists have been following the images collected by the MODIS instruments mounted onboard NASA’s Aqua and Terra satellites, which reveal a significant fire in western Greenland.
MODIS, or Moderate Resolution Imaging Spectroradiometer, is a 36-channel visible- to thermal-infrared sensor. MODUS’s thermal camera, called VIIRS for visible infrared imaging radiometer suite, is used to identify anomalous temperatures, which can be caused by volcanoes and gas flares as well as fires. Anomalies are classified based on temperature variation from background, so detection is enhanced at night time when air and soil temperatures drop, as well as at high latitudes.
MODIS was launched initially in 1999 on board the Terra satellite, and later in 2002 onboard the Aqua satellite. While MODUS imagery is relatively low resolution compared to other satellite images (250 m for visible light and 375 m for VIIRS), its near daily capture and rapid delivery via projects like LANCE (Land, Atmosphere Near real-time Capability for EOS) makes it one of the best remote sensing solutions for fire tracking and observation.
For ultra-remote areas like Greenland, these fires would often go undetected, but the accessible nature of the MODIS datasets means anyone with an internet connection can view and download the imagery online. Several sources are reporting that the fire is vast. It is approximately 15-20 km2, which is about 2000 hectares. To provide a sense of scale, that’s about 100 time smaller than any of the individual fires currently burning in British Columbia. While the fire is small by all sensible standards, any fire in Greenland is noteworthy.
The type of vegetation found on Greenland, most of which is underfoot or very low, is not conducive to the spread of fire. Scientists believe the vegetation that is fueling the fire to be primarily peat that was formerly frozen within the permafrost. The significance of thawed, dried peat might be lost on the average observer, but to arctic ecologists, it suggests the ground is warm. There is not enough evidence to say this summer’s unusually active fires are caused by global warming, but you can bet more eyes will be on Greenland’s thermal imagery from now on.