The 'pyrocumulonimbus' (pyroCb) is a type of cumulus cloud formed above a source of heat such as a
wildfire and may sometimes even extinguish the fire that formed it. It is the most extreme manifestation of
pyrocumulus. According to the
American Meteorological Society’s Glossary of Meteorology, a pyrocumulus is a cumulus cloud formed by a rising thermal from a fire, or enhanced by buoyant plume emissions from an industrial combustion process
[1]. Analogous to the meteorological distinction between
cumulus and
cumulonimbus, the pyrocumulonimbus is a fire-aided or –caused convective cloud but with considerable vertical development. The pyroCb reaches the upper
troposphere or even lower
stratosphere and may involve
precipitation (although usually light),
hail, lightning, extreme low-level
winds, and in some cases even
tornadoes
[2]. The pyroCb was named following the discovery that extreme manifestations of this pyroconvection caused direct injection of large abundances of smoke into the lower stratosphere
[3]>
[4]
Alternate spelling and abbreviations for pyrocumulonimbus that may be found in the literature include pyro-cumulonimbus, pyro-cb, pyro-Cb and pyrocb.
References
1. Pyrocumulus entry in the AMS Glossay
2. Fromm, M., A. Tupper, D. Rosenfeld, R. Servranckx, and R. McRae, Violent pyro-convective storm devastates Australia's capital and pollutes the stratosphere. Geophysical Research Letters, 2006. 33: p. L05815, doi:10.1029/2005GL025161
3. Fromm, M., et al., Observations of boreal forest fire smoke in the stratosphere by POAM III, SAGE II, and lidar in 1998. Geophysical Research Letters, 2000. 27: p. 1407-1410.
4. Fromm, M. and R. Servranckx, Transport of forest fire smoke above the tropopause by supercell convection. Geophysical Research Letters, 2003. 30(10): p. 1542.