Abstract
Four distinct meteorological regimes in the Amazon basin have been examined to distinguish the contributions from boundary layer aerosol and convective available potential energy (CAPE) to continental cloud structure and electrification. The lack of distinction in the electrical parameters (peak flash rate, lightning yield per unit rainfall) between aerosol-rich October and aerosol-poor November in the premonsoon regime casts doubt on a primary role for the aerosol in enhancing cloud electrification. Evidence for a substantial role for the aerosol in suppressing warm rain coalescence is identified in the most highly polluted period in early October. The electrical activity in this stage is qualitatively peculiar. During the easterly and westerly wind regimes of the wet season, the lightning yield per unit of rainfall is positively correlated with the aerosol concentration, but the electrical parameters are also correlated with CAPE, with a similar degree of scatter. Here cause and effect are difficult to establish with available observations. This ambiguity extends to the ‘‘green ocean’’ westerly regime, a distinctly maritime regime over a major continent with minimum aerosol concentration, minimum CAPE, and little if any lightning.
Original language | English (US) |
---|---|
Article number | 8082 |
Journal | Journal of Geophysical Research: Atmospheres |
Volume | 107 |
Issue number | D20 |
DOIs | |
State | Published - 2002 |
All Science Journal Classification (ASJC) codes
- Geophysics
- Space and Planetary Science
- Earth and Planetary Sciences (miscellaneous)
- Atmospheric Science
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In: Journal of Geophysical Research: Atmospheres, Vol. 107, No. D20, 8082, 2002.
Research output: Contribution to journal › Article › peer-review
TY - JOUR
T1 - Contrasting convective regimes over the Amazon
T2 - Implications for cloud electrification
AU - Williams, E.
AU - Rosenfeld, D.
AU - Madden, N.
AU - Gerlach, J.
AU - Gears, N.
AU - Atkinson, L.
AU - Dunnemann, N.
AU - Frostrom, G.
AU - Antonio, M.
AU - Biazon, B.
AU - Camargo, R.
AU - Franca, H.
AU - Gomes, A.
AU - Lima, M.
AU - Machado, R.
AU - Manhaes, S.
AU - Nachtigall, L.
AU - Piva, H.
AU - Quintiliano, W.
AU - Machado, L.
AU - Artaxo, P.
AU - Roberts, G.
AU - Renno, N.
AU - Blakeslee, R.
AU - Bailey, J.
AU - Boccippio, D.
AU - Betts, A.
AU - Wolff, D.
AU - Roy, B.
AU - Halverson, J.
AU - Rickenbach, T.
AU - Fuentes, J.
AU - Avelino, E.
N1 - Funding Information: [64] Acknowledgments. Numerous individuals contributed to the success of the field program in Brazil. Generous logistical support from Joao Luiz Esteves (008) and Eduardo Conceicao de Locerda (007) of INCRA was invaluable. E. Amitai, R. Bowie, C. Christina, R. Ferreira, Z. Haddad, P. Kuchera, C Morales, E. Plows, L. Pereira, R. Toracinta, and J. Wang all devoted many hours to radar operations. Gilberto Fisch enthusiastically encouraged student participation. Coordination with the crew at the ABRACOS site, including M. Garstang, B. Ferrier, D. Penny, R. Heitz, J. Tota, and J. Sigler, enhanced the value of simultaneous data sets. Jim Wilson provided able assistance in selection of radar sites, Jon Lutz loaned radar equipment, Bob Boldi organized data acquisition systems, Elizangela de Araujo Silva filled gaps in the river record, Marx Brook and Dave Rust loaned field change antennae, John Hall and Karen Rothkin produced figures, and Jose Rosa provided assistance with the meteorological data archive in Brasilia. R. Barchet and N. Laulainin of Battelle Laboratories generously loaned the CCN counter for this field program. E. Betterton, S. Twomey, and G. Shaw provided valuable instruction and advice in its operation and maintenance. J. Beck, T. Germano, A. L. Loureiro, E. Fernandes, and A. Ribeiro devoted considerable time toward sustaining the operation of both particle counters. The Brazil Lightning Detection Network was established through the able assistance of Evandro Ferraz, Osmar Pinto, and the hard work of dozens of unnamed contributors in the Rondonian towns of Guajara-Mirim, Machadinho do Oeste, Vilhena, and Ouro Preto. Additional financial support for the BLDN was provided by Augusto Cesar Vaz de Athayde at INMET in Brasilia. We also thank Alaor Dell’Antonia for assistance with the meteorological data there. Valuable discussions on problems of aerosol and tropical convection with M. Andreae, M. Silva Dias, M. Baker, E. Betterton, L. Carey, A. Detwiler, J. Dye, P. Dias, B. Ferrier, M. Garstang, J. Hallett, L. Harrison, G. Heymsfeld, A. Hogan, J. Hudson, A. Khain, G. Lala, W. Lyons, D. MacGorman, R. Markson, R. Orville, S. Rutledge, R. Sagalyn, V. Schroeder, J. Stith, S. Twomey, G. Vali, J. Willett, and E. Zipser are appreciated. Steve Rutledge led the way across the Amazon from the U.S. side to make this program happen. Ramesh Kakar and Otto Thiele of NASA GSFC paid for it, on NASA grant NAG5-4778. P. Artaxo acknowledges support from FAPESP. M. de Agostinho acknowledges support from NASA Ames and from FAPESP. G. Roberts was supported by the Max Planck Institute of Chemistry. D. Rosenfeld and E. Williams acknowledge support from the U.S.-Israel Binational Science Foundation, grant 037-8274. Last, but far from least, the first author extends his appreciation to the families Carvalho de Souza, Dutra, and Vitorino (Ouro Preto); Esteves (Ji Parana); Avelino (Porto Velho); and Rosa, Coelho, and Oliveira (Brasilia) for their kind hospitality during the adventure in Brazil. Funding Information: Numerous individuals contributed to the success of the field program in Brazil. Generous logistical support from Joao Luiz Esteves (008) and Eduardo Conceicao de Locerda (007) of INCRA was invaluable. E. Amitai, R. Bowie, C. Christina, R. Ferreira, Z. Haddad, P. Kuchera, C Morales, E. Plows, L. Pereira, R. Toracinta, and J. Wang all devoted many hours to radar operations. Gilberto Fisch enthusiastically encouraged student participation. Coordination with the crew at the ABRACOS site, including M. Garstang, B. Ferrier, D. Penny, R. Heitz, J. Tota, and J. Sigler, enhanced the value of simultaneous data sets. Jim Wilson provided able assistance in selection of radar sites, Jon Lutz loaned radar equipment, Bob Boldi organized data acquisition systems, Elizangela de Araujo Silva filled gaps in the river record, Marx Brook and Dave Rust loaned field change antennae, John Hall and Karen Rothkin produced figures, and Jose Rosa provided assistance with the meteorological data archive in Brasilia. R. Barchet and N. Laulainin of Battelle Laboratories generously loaned the CCN counter for this field program. E. Betterton, S. Twomey, and G. Shaw provided valuable instruction and advice in its operation and maintenance. J. Beck, T. Germano, A. L. Loureiro, E. Fernandes, and A. Ribeiro devoted considerable time toward sustaining the operation of both particle counters. The Brazil Lightning Detection Network was established through the able assistance of Evandro Ferraz, Osmar Pinto, and the hard work of dozens of unnamed contributors in the Rondonian towns of Guajara-Mirim, Machadinho do Oeste, Vilhena, and Ouro Preto. Additional financial support for the BLDN was provided by Augusto Cesar Vaz de Athayde at INMET in Brasilia. We also thank Alaor Dell’Antonia for assistance with the meteorological data there. Valuable discussions on problems of aerosol and tropical convection with M. Andreae, M. Silva Dias, M. Baker, E. Betterton, L. Carey, A. Detwiler, J. Dye, P. Dias, B. Ferrier, M. Garstang, J. Hallett, L. Harrison, G. Heymsfeld, A. Hogan, J. Hudson, A. Khain, G. Lala, W. Lyons, D. MacGorman, R. Markson, R. Orville, S. Rutledge, R. Sagalyn, V. Schroeder, J. Stith, S. Twomey, G. Vali, J. Willett, and E. Zipser are appreciated. Steve Rutledge led the way across the Amazon from the U.S. side to make this program happen. Ramesh Kakar and Otto Thiele of NASA GSFC paid for it, on NASA grant NAG5-4778. P. Artaxo acknowledges support from FAPESP. M. de Agostinho acknowledges support from NASA Ames and from FAPESP. G. Roberts was supported by the Max Planck Institute of Chemistry. D. Rosenfeld and E. Williams acknowledge support from the U.S. Israel Binational Science Foundation, grant 037-8274. Last, but far from least, the first author extends his appreciation to the families Carvalho de Souza, Dutra, and Vitorino (Ouro Preto); Esteves (Ji Parana); Avelino (Porto Velho); and Rosa, Coelho, and Oliveira (Brasilia) for their kind hospitality during the adventure in Brazil. Publisher Copyright: © 2002 by the American Geophysical Union.
PY - 2002
Y1 - 2002
N2 - Four distinct meteorological regimes in the Amazon basin have been examined to distinguish the contributions from boundary layer aerosol and convective available potential energy (CAPE) to continental cloud structure and electrification. The lack of distinction in the electrical parameters (peak flash rate, lightning yield per unit rainfall) between aerosol-rich October and aerosol-poor November in the premonsoon regime casts doubt on a primary role for the aerosol in enhancing cloud electrification. Evidence for a substantial role for the aerosol in suppressing warm rain coalescence is identified in the most highly polluted period in early October. The electrical activity in this stage is qualitatively peculiar. During the easterly and westerly wind regimes of the wet season, the lightning yield per unit of rainfall is positively correlated with the aerosol concentration, but the electrical parameters are also correlated with CAPE, with a similar degree of scatter. Here cause and effect are difficult to establish with available observations. This ambiguity extends to the ‘‘green ocean’’ westerly regime, a distinctly maritime regime over a major continent with minimum aerosol concentration, minimum CAPE, and little if any lightning.
AB - Four distinct meteorological regimes in the Amazon basin have been examined to distinguish the contributions from boundary layer aerosol and convective available potential energy (CAPE) to continental cloud structure and electrification. The lack of distinction in the electrical parameters (peak flash rate, lightning yield per unit rainfall) between aerosol-rich October and aerosol-poor November in the premonsoon regime casts doubt on a primary role for the aerosol in enhancing cloud electrification. Evidence for a substantial role for the aerosol in suppressing warm rain coalescence is identified in the most highly polluted period in early October. The electrical activity in this stage is qualitatively peculiar. During the easterly and westerly wind regimes of the wet season, the lightning yield per unit of rainfall is positively correlated with the aerosol concentration, but the electrical parameters are also correlated with CAPE, with a similar degree of scatter. Here cause and effect are difficult to establish with available observations. This ambiguity extends to the ‘‘green ocean’’ westerly regime, a distinctly maritime regime over a major continent with minimum aerosol concentration, minimum CAPE, and little if any lightning.
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UR - http://www.scopus.com/inward/citedby.url?scp=84925662475&partnerID=8YFLogxK
U2 - 10.1029/2001JD000380
DO - 10.1029/2001JD000380
M3 - Article
AN - SCOPUS:84925662475
SN - 2169-897X
VL - 107
JO - Journal of Geophysical Research: Atmospheres
JF - Journal of Geophysical Research: Atmospheres
IS - D20
M1 - 8082
ER -