Pyrocumulonimbus cloud

The pyrocumulonimbus cloud (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 [ [http://amsglossary.allenpress.com/glossary/search?p=1&query=pyrocumulus&submit=Search Pyrocumulus entry in the AMS Glossay] ] . 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 [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] . 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 [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.] [Fromm, M. and R. Servranckx, Transport of forest fire smoke above the tropopause by supercell convection. Geophysical Research Letters, 2003. 30(10): p. 1542.]

Alternate spelling and abbreviations for pyrocumulonimbus that may be found in the literature include pyro-cumulonimbus, pyro-cb, pyro-Cb and pyrocb.

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