On November 4, 2021, the US Forest service conducted a 1,282 prescribed burn in the Ocala National Forest in north central Florida. Prescribed burns are effective at reducing wildfire risk because the controlled burn removes excess fuel loads and decreases forest overgrowth. The Florida Forestry service duly notified the public ahead of time via Twitter (Figure 1).
A 1,282 acre fire would be exceedingly radiant to a satellite hot spot detection sensor. However, due to widespread cloud coverage over the Florida peninsula, there was no effective way for MODIS and VIIRS satellites to detect the prescribed burn. See the GOES satellite animation (Figure 2) below that shows overcast skies. That the MODIS/VIIRS hot spot detection lacked a detection for the prescribed burn can be seen in Figure 3.
Weather radars are primarily designed to detect hydrometeors (water targets), but in this situation the weather radar in Jacksonville, Florida (WSR-88D KJAX) detected the prescribed burn's smoke plume (Figure 4). The primary hypothesis is that scattering on weather radar is due to ash, though very few studies have documented the scattering properties of pyrometeors (i.e., partially burnt vegetation ash and debris). However, use of weather radar in smoke plume detection is not completely new. Weather radar detected many of the 2021 wildfires in the western United States and there is empirical evidence of positive correlation between the radar detected ash plume with fire intensity. See Wildfire and Weather Radar: A Review for a scientific discussion on the topic.
This use case of using more than one type of sensor/data source to detect wildfires, demonstrates the untapped potential in today's world of abundant weather and climate data. 81 Degrees, LLC is exploring new ways to leverage data and technology to improve its customers lives and businesses. Check out our recent video on Google Cloud's Earth Engine. Contact us if you need support leveraging multiple sources of weather and climate data.
This article is also posted on 81 Degrees, LLC's fireAlert.app platform.