False fire is observed outside wildfire perimeters in some cases when a super heated smoke plume can set off false fire during nighttime detection. This false fire artifact has been observed in the past, and has been documented in the S-NPP fire product VNP14IMG. In these cases a hot plume is detected, which carries a signature that is easily confused with that of the "real" fire perimeter. The tall heat plume combined with the high view angle will be projected laterally on the surface, generating a false fire artifact. The artifacts are usually observed in the nighttime data as typically these super plumes tend to be flagged as clouds in the daytime scenes which prevents this detection. Users are advised to reference the VNP14 user guide in this LINK for more details.

The first image below is an example image from the FIRMS website, which shows the N20 (J1) VIIRS active fire product reporting a fire detected on July 14th, 2020 (2020.196) over Northern California, west of Coalinga. The blue dot highlights the projection of the false fire that is being detected by the active fire algorithm in the presence of a hot plume at high altitude over the true fire on the ground, which could be several kilometers away from the actual fire perimeter. This false fire is observed in granule J114IMG.A2020196.2206.002.2020197132020.nc.

Occurrence: Land SIPS AS 3194, JJ114IMG Active Fire product for the dates and times described above.

PGE: ?

Case Name: PM_N20_VAFIP_20199