Atmospheric Chemistry and Physics
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10.5194/acp-7-645-2007
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http://www.atmos-chem-phys.net/7/645/2007/acp-7-645-2007.pdf
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2007-02-09
The Chisholm firestorm: observed microstructure, precipitation and lightning activity of a pyro-cumulonimbus
D. Rosenfeld
daniel.rosenfeld@huji.ac.il
M. Fromm
J. Trentmann
G. Luderer
M. O. Andreae
R. Servranckx
Institute of Earth Sciences, The Hebrew University of Jerusalem, Israel
Naval Research laboratory, Washington, D.C. 20375, USA
Institute for Atmospheric Physics, University of Mainz, Germany
Max Planck Institute for Chemistry, Mainz, Germany
Canadian Meteorological Centre, Meteorological Service of Canada, Montreal, Canada
now at: Umweltbundesamt, Dessau, Germany
A fire storm that occurred on 28 May 2001 and devastated the town of
Chisholm, ~150 km north of Edmonton, Alberta, induced a violent
fire-invigorated cumulonimbus cloud. This pyro-cumulonimbus (pyro-Cb) had
overshooting tops of 2.5–3 km above the tropopause, and injected massive
amounts of smoke into the lower stratosphere. Fortunately, this event
occurred under good coverage of radar, rain gauge, lightning and satellite
measurements, which allowed in-depth documentation of the event, and gave us
an opportunity to study the cloud top morphology and microstructure,
precipitation and cloud electrification of the pyro-Cb.
<br><br>
The combination of heat and smoke created a cloud with extremely small
drops, which ascended rapidly in violent updrafts. There appeared to be
little freezing up to the homogeneous freezing isotherm level of −38°C.
A cloud with such small and short-lived highly supercooled drops is
incapable of producing precipitation except for few large graupel and hail,
which produced the observed radar echoes and charged the cloud with positive
lightning. The small cloud drops froze homogeneously to equally small ice
particles, for which there is no mechanism to aggregate into precipitation
particles, and which hence remain in the anvil. The lack of significant
precipitation implies that only a small fraction of the smoke is scavenged,
so that most of it is exhausted through the anvil to the upper troposphere
and lower stratosphere.
<br><br>
Comparisons with other cases suggest that a pyro-Cb does not have to be as
violent as the Chisholm case for precipitation to be strongly suppressed.
However, this level of convective vigor is necessary to create the
overshooting updraft that injects the smoke into the lower stratosphere.
Andreae, M. O., Rosenfeld, D., Artaxo, P., Costa, A. A., Frank, G. P., Longo, K. M., and Silva-Dias, M. A. F.: Smoking rain clouds over the Amazon, Science, 303, 1337–1342, 2004.
ASRD: Final Documentation Report – Chisholm Fire (LWF-063), Forest Protection Division, ISBN 0-7785-1841-8, Tech. rep., Alberta Sustainable Resource Development, 53 p., 2001.
Burrows, W. R., King, P., Lewis, P. J., Kochubajda, B., Snyder, B., and Turcotte, V.: Lightning Occurrence Patterns over Canada and Adjacent United States from Lightning Detection Network Observations, Atmosphere-Ocean, 40, 59–81, 2002.
Carey, L. D., Petersen, W. A., and Rutledge, S. A.: Evolution of cloud-to-ground lightning and storm structure in the Spencer, South Dakota, tornadic supercell of 30 May 1998, Mon. Wea. Rev., 131, 1811–1831, 2003a.
Carey, L. D., Rutledge, S. A., and Petersen, W. A.: The relationship between severe storm reports and cloud-to-ground lightning polarity in the contiguous United States from 1989 to 1998, Mon. Wea. Rev., 131, 1211–1228, 2003b.
Diner, D. J., Beckert, J. C., Reilly, T. H., Bruegge, C. J., Conel, J. E., Kahn, R., Martonchik, J. V., Ackerman, T. P., Davies, R., Gerstl, S. A. W., Gordon, H. R., Muller, J.-P., Myneni, R. B., Sellers, R. J., Pinty, B., and Verstraete, M. M.: Multiangle Imaging SpectroRadiometer (MISR) description and experiment overview, IEEE Trans. Geosc. Rem. Sens., 36, 1072–1087, 1988.
Fromm, M., Bevilacqua, R., Servranckx, R., Rosen, J., Thayer, J. P., Herman, J., and Larko, D.: Pyro-cumulonimbus injection of smoke to the stratosphere: Observations and impact of a super blowup in northwestern Canada on 3–4 August 1998, J. Geophys. Res., 110, D08205, doi:10.1029/2004JD005350, 2005.
Fromm, M., Tupper, A., Rosenfeld, D., Servranckx, R., and McRae, R., Violent pyro-convective storm devastates Australia's capital and pollutes the stratosphere: Geophys. Res. Lett., 33, L05815, doi:10.1029/2005GL025161, 2006.
Fromm, M. D. and Servranckx, R.: Transport of forest fire smoke above the tropopause by supercell convection, Geophys. Res. Lett., 30, 1542, doi:10.1029/2002GL016820, 2003.
Hallett, J., Hudson, J. G., and Rogers, C. F.: Characterization of combustion aerosols for haze and cloud formation, Aerosol Sci. Technol., 10, 70–83, 1989.
Inoue, T.: A cloud type classification with NOAA 7 split-window measurements, J. Geophys. Res., 92, 3991–4000, 1987.
Jost, H.-J., Drdla, K., Stohl, A., et al.: In-situ observations of mid-latitude forest fire plumes deep in the stratosphere, Geophys. Res. Lett., 31, L11101, doi:10.1029/2003GL019253, 2004.
Jungwirth, P., Rosenfeld, D., and Buch, V.: A possible new molecular mechanism of thundercloud Electrification, Atmos. Res., 76, 190–205, 2005.
Kaufman, Y. J. and Fraser, R. S.: The Effect of Smoke Particles on Clouds and Climate Forcing, Science, 277, 1636–1639, 1977.
Kochtubjada, B., Stewart, R. E., Gyakum, J. R., and Flannigan, M. D.: Summer convection and lightning over the Mackenzie River basin and their impacts during 1994 and 1995, Atmosphere-Ocean, 40, 199–220, 2002.
Lang, T. J. and Rutledge, S. A.: Cloud-to-ground lightning downwind of the 2002 Hayman forest fire in Colorado, Geophys. Res. Lett., 33, L03804, doi:10.1029/2005GL024608, 2006.
Latham, D. J.: Lightning flashes from a prescribed fire influenced cloud, J. Geophys. Res., 96, 17 151–17 157, 1991.
Latham, D. J.: Space charge generated by wind tunnel fires, Atmos. Res., 51, 267–278, 1999.
Latham, D. and Williams, E. R.: Lightning and Forest Fires, in: Forest Fires – Behavior and Ecological Effects, edited by: Johnson, E. A. and Miyanashi, K., Academic Press, New York, 2001.
LavouĂ©,~D., Liousse, C., Cachier,~H., Stocks, B. J., and Goldammer, J. G.: Modeling of carbonaceous particles emitted by boreal and temperature wildfires at northern latitudes, J. Geophys. Res., 105, 26 871–26 890, doi:10.1029/2000JD900180.
Leroy, D., Monier, M., Wobrock, W., and Flossmann, A. I.: A numerical study of the effects of the aerosol particle spectrum on the development of the ice phase and precipitation formation, Atmos. Res., 80, 15–45, 2006.
Luderer, G., Trentmann, J., Winterrath, T., Textor, C., Herzog, M., Graf, H.-F., and Andreae, M. O.: Modeling of biomass smoke injection into the lower stratosphere by a large forest fire (part II): Sensitivity studies, Atmos. Chem. Phys., 6, 5261–5277, 2006.
Orville, R. E., Huffines, G. R., Burrows, W. R., Holle, R. L., and Cummins, K. L.: The North American Lightning Detection Network (NALDN) – First Results: 1998–2000, Mon. Wea. Rev., 130, 2098–2109, 2002.
Radke, L. F., Ward, D. E., and Riggan, P. J.: A prescription for controlling the air pollution resulting from the use of prescribed biomass fire: clouds, Int. J. Wildland Fire, 10, 103–111, 2001.
Rogers, C. F., Hudson, J. G., Zielinska, B., Tanner, R. L., Hallett, J., and Watson, J. G.: Cloud condensation nuclei from biomass burning, in: Global Biomass Burning: Atmospheric, Climatic and Biospheric Implications, edited by: Levine, J. S., pp. 431–438, MIT Press, Cambridge, Mass., 1991.
Rosenfeld, D.: TRMM observed first direct evidence of smoke from forest fires inhibiting rainfall, Geophys. Res. Lett., 26, 3105–3108, 1999.
Rosenfeld, D.: Suppression of rain and snow by urban and industrial air pollution, Science, 287, 1793–1796, 2000.
Rosenfeld, D. and Gutman, G.: Retrieving microphysical properties near the tops of potential rain clouds by multispectral analysis of AVHRR data, Atmos. Res., 34, 259–283, 1994.
Rosenfeld, D. and Lensky, I. M.: Satellite-based insights into precipitation formation processes in continental and maritime convective clouds, Bull. Am. Meteorol. Soc., 79, 2457–2476, 1998.
Rosenfeld, D. and Woodley, W. L.: Deep convective clouds with sustained supercooled liquid water down to −37.5°C, Nature, 405, 440–442, 2000.
Rosenfeld, D. and Woodley, W. L.: Closing the 50-year circle: From cloud seeding to space and back to climate change through precipitation physics, in: Cloud Systems, Hurricanes, and the Tropical Rainfall Measuring Mission (TRMM), edited by: Tao, W.-K. and Adler, R., pp. 59–80, AMS, 2003.
Rosenfeld, D., Woodley, W. L., Krauss, T. W., and Makitov, V.: The Structure of Severe Convective Storms in Mendoza, Argentina, J. Appl. Meteorol. Climatol., 45, 1261–1281, 2006.
Setvak, M., Rabin, R. M., Doswell, C. A., and Levizzani, V.: Satellite observations of convective storm tops in the 1.6, 3.7 and 3.9 $\mu $m spectral bands, Atmos. Res., 67-8, 607–627, 2003.
Takahasi, T. M. and Miyawaki, K.: Reexamination of riming electrification in a wind tunnel, J. Atmos. Sci., 59, 1018–1025, 2002.
Trentmann, J., Luderer, G., Winterrath, T., Fromm, M., Servranckx, R., Textor, C., Herzog, M., Graf, H.-F., and Andreae, M. O.: Modeling of biomass smoke injection into the lower stratosphere by a large forest fire (part I): Reference simulation, Atmos. Chem. Phys., 6, 5247–5260, 2006.
Vonnegut, B., Latham, D. J., Moore, C. B., and Hunyady, S. J.: An explanation for anomalous lightning from forest fire clouds, J. Geophys. Res., 100, 5037–5050, 1995.
Warner, J. and Twomey, S.: The production of cloud nuclei by cane fires and the effect on cloud drop concentrations, J. Atmos. Sci., 24, 704–706, 1967.
Williams, E., Mushtak, V., Rosenfeld, D., Goodman, S., and Boccippio, D.: Thermodynamic conditions favorable to superlative thunderstorm updraft, mixed phase microphysics and lightning flash rate, Atmos. Res., 76, 288–306, 2005.
Williams, E., Rosenfeld, D., Madden, N., et al.: Contrasting convective regimes over the Amazon: Implications for cloud electrification, J. Geophys. Res., 107, 8082, doi:10.1029/2001JD000380, 2002.