The Loma fire in California
Between 0900 and 1000 UTC on 27 September (2 AM and 3 AM PDT) Suomi NPP overflew the Loma fire that is burning in the high terrain between Santa Clara and Santa Cruz counties in northern California. (News Article 1; News Article 2) The toggle above shows the glow of the fire in the nighttime visible imagery from the Day/Night Band on the VIIRS instrument. This glow is along the border of the two counties, well removed from the glow of nearby cities. The fire hot spot as detected by the 3.7 micron channel is apparent as well. Smoke from the fire is difficult to detect in this low-light scene (the waxing quarter moon was below the horizon at the time of the image, shedding no light on the scene).GOES-15 can provide 3.9 µm imagery roughly 4 times per hour (when GOES-R is launched, shortwave infrared imagery will be produced every 5 minutes over the continental United States) allowing a better indication of how the fire is evolving with time. The animation below, from 0500 through 1530 UTC, shows a cooling trend in the warmest pixels (hottest pixels are colored red in the animation, then yellow, then black), which is expected as winds that drive the fire relax at night. There is notable motion in the navigation of this image. GOES-15 is operating with only 1 Star Tracker (vs. the usual 3), resulting in less-precise image navigation.
Visible Imagery from GOES-15 after sunrise on 27 September shows a long smoke plume moving southeastward from the fire source.