Wildfire in the Seward Peninsula of Alaska

June 16th, 2019 |

GOES-17

GOES-17 “Red” Visible (0.64 µm) and Shortwave Infrared (3.9 µm) images [click to play animation | MP4]

1-minute Mesoscale Domain Sector GOES-17 (GOES-West) “Red” Visible (0.64 µm) and Shortwave Infrared (3.9 µm) images (above) showed a smoke plume and pyrocumulus clouds in addition to the thermal anomaly (or “hot spot”) associated with the lightning-initiated North River wildfire burning in the far eastern Seward Peninsula of Alaska on 16 June 2019. It is interesting to note that shortly after the wildfire exhibited a peak Shortwave Infrared brightness temperature of 94.5ºC at 2124 UTC, a distinct pyrocumulus cloud “jump” was seen in the Visible imagery (which appeared to peak in vertical extent around 2131 UTC, as seen in this short animation).

A sequence of 3 Suomi NPP VIIRS Shortwave Infrared (3.74 µm) and Visible (0.64 µm) images (below) also showed the fire thermal anomaly (black to red pixels) and the smoke plume.

Suomi NPP VIIRS Shortwave Infrared (3.74 µm) and Visible (0.64 µm) images, with surface observations plotted in yellow [click to enlarge]

Suomi NPP VIIRS Shortwave Infrared (3.74 µm) and Visible (0.64 µm) images, with surface observations plotted in yellow [click to enlarge]

In fact, the south-southwestward transport of smoke restricted the surface visibility to 5 miles at Unalakeet and 4 miles at St. Michael (below), located about 100 to 150 miles from the fire respectively.

Time series plot of surface observation data from Unalakeet [click to enlarge]

Time series plot of surface observation data from Unalakeet [click to enlarge]

Time series plot of surface observation data from St. Michael [click to enlarge]

Time series plot of surface observation data from St. Michael [click to enlarge]

A NOAA-20 VIIRS True Color Red-Green-Blue (RGB) image viewed using RealEarth (below) showed significant residual smoke aloft (from the previous day of that wildfire’s growth) arcing westward then southward over the Bering Sea; however, since smoke is effectively transparent at the 11.45 µm Infrared Window wavelength, there was no smoke signature seen in that particular image.

NOAA-20 VIIRS True Color RGB and Infrared Window (11.45 µm) images [click to enlarge]

NOAA-20 VIIRS True Color RGB and Infrared Window (11.45 µm) images [click to enlarge]