Pyrocumulonimbus clouds produced by the Cameron Peak Fire in Colorado

By Scott Bachmeier • 6 September 2020

GOES-16 “Red” Visible (0.64 µm, top left), Shortwave Infrared (3.9 µm, top right), Fire Temperature RGB + GLM Flash Extent Density (bottom left) and “Clean” Infrared Window (10.35 µm, bottom right) [click to play animation | MP4]

This fire also produced a brief pyroCb cloud on the previous day (below), as shown by a single blue (-40ºC) pixel on the 10.35 µm image at 2301 UTC — however, since no Mesoscale Sector was positioned over the area, the fire was only sampled by 5-minute CONUS Sector images. The presence of cloud-top infrared brightness temperatures of -40ºC and colder assures heterogeneous nucleation of all supercooled water droplets to form ice crystals, thereby meeting the criteria of a pyroCb.

GOES-16 “Red” Visible (0.64 µm, top left), Shortwave Infrared (3.9 µm, top right), Fire Temperature RGB + GLM Flash Extent Density (bottom left) and “Clean” Infrared Window (10.35 µm, bottom right) [click to play animation | MP4]

===== 07 September Update =====

Suomi NPP VIIRS Shortwave Infrared (3.74 µm) and Day/Night Band (0.7 µm) images, with plots of METAR surface reports [click to enlarge]

A toggle between Shortwave Infrared images from Suomi NPP VIIRS (3.74 µm) and GOES-16 ABI (3.9 µm) is shown below — the shape of the Cameron Peak Fire thermal anomaly as well as locations of ongoing hot fires along its perimeter were more accurately seen in the 375-m resolution VIIRS image, compared to the 2-km resolution (at satellite sub-point) ABI image. The 2 images are time-matched to correspond to the 0922 UTC time of the Suomi NPP satellite’s overpass.

Shortwave Infrared images from Suomi NPP (3.74 µm) and GOES-16 (3.9 µm), with plots of METAR surface reports [click to enlarge]

Categories: Air quality, Fire detection, GOES-16, Suomi NPP, VIIRS