Detection and Monitoring of Intense Pyroconvection from New Generation Geostationary Sensors

Intense fire-triggered thunderstorms, known as pyrocumulonimbus (or pyroCb), can alter fire behavior, influence smoke plume trajectories, and hinder fire suppression efforts.  PyroCb are also known for injecting a significant quantity of aerosol mass into the upper-troposphere and lower-stratosphere (UTLS).  The Naval Research Laboratory (NRL) has developed the first automated near-real-time pyroCb detection algorithm using the current generation of GOES imagers in North America, providing evidence that pyroCb are likely an endemic feature of regional summer climate.  This algorithm was recently applied to the new generation Advanced Himawari Imager (AHI), extending pyroCb detection capabilities to Asia and Australia.  PyroCb detection from AHI also provides an important test of future pyroCb detection capabilities over North America from the Advanced Baseline Imager (ABI) aboard GOES-R and GOES-S.  The algorithm uses multispectral infrared observations to isolate deep convective clouds with the distinct microphysical signal of pyroCb.  Imagery is posted immediately to an NRL-maintained web page for rapid analysis of potential pyroCb events.  Application of this algorithm in regions known to have a high frequency of pyroCb occurrence resulted in detection of individual intense events, pyroCb embedded within traditional convection, and multiple, short-lived pulses of activity.  Comparisons with a community inventory indicate that this algorithm captures the majority of pyroCb.  The primary limitation of the current system in North America is that pyroCb anvils can be small relative to satellite effective pixel size, especially in regions with large viewing angles.  The algorithm is also sensitive to some false positives from traditional convection that either ingests smoke or exhibits extreme updraft velocities.  New generation geostationary sensors with improved spatial resolution and multispectral capabilities, such as AHI and ABI, will therefore offer significant advantages for achieving the goal of global near-real-time pyroCb detection.