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@Article{PickeringTWTMKHSBGB:1996:CoTrBi,
               author = "Pickering, K. E. and Thompson, A. M. and Wang, Y. and Tao, W. K. 
                         and McNamara, D. P. and Kirchhoff, Volker Walter Johann Heinrich 
                         and Heikes, B. G. and Sachse, G. W. and Bradshaw, J. D. and 
                         Gregory, G. L. and Blake, D. R",
                title = "Convective transport of biomass burning emissions over Brazil 
                         during TRACE A",
              journal = "Journal of Geophysical Research",
                 year = "1996",
               volume = "101",
               number = "(D19)",
                pages = "23993--24012",
                month = "Oct.",
             keywords = "GEOF{\'{\I}}SICA ESPACIAL, Brasil, transporte de gas, biomassa, 
                         combust{\~a}o, emiss{\~a}o, troposfera, oz{\^o}nio, gas 
                         transport, biomass, combustion, emission, troposphere, ozone.",
             abstract = "A series of large mesoscale convective systems that occurred 
                         during the Brazilian phase of GTE/TRACE A (Transport and 
                         Atmospheric Chemistry near the Equator-Atlantic) provided an 
                         opportunity to observe deep convective transport of trace gases 
                         from biomass burning. This paper reports a detailed analysis uf 
                         flight 6, on September 27, 1992, which sampled cloud- and 
                         biomass-burning-perturbed regions north of Brasilia. 
                         High-frequency sampling of cloud outflow at 9-12 km from the NASA 
                         DC-8 showed enhancement of CO mixing ratios typically a factor of 
                         3 above background (200-300 parts per billion by volume (ppbv) 
                         versus 90 ppbv) and significant increases in NO, and hydrocarbons, 
                         Clear signals of lightning-generated NO were detected; we estimate 
                         that at least 40of NOx at the 9.5-km level and 32 at 11.3 km 
                         originated from lightning, Four types of model studies have been 
                         performed to analyze the dynamical and photochemical 
                         characteristics of the series of convective events. (1) Regional 
                         simulations for the period have been performed with the NCAR/Penn 
                         State mesoscale model (MM5), including tracer transport of carbon 
                         monoxide, initialized with observations. Middle-upper tropospheric 
                         enhancements of a factor of 3 above background are reproduced. (2) 
                         A cloud-resolving model (the Goddard cumulus ensemble (GCE) model) 
                         has been run for one representative convective cell during the 
                         September 26-27 episode. (3) Photochemical calculations (the 
                         Goddard tropospheric chemical model), initialized with trace gas 
                         observations (e.g., CO, NOx, hydrocarbons, O-3) observed in cloud 
                         outflow, show appreciable O-3 formation postconvection, initially 
                         up to 7-8 ppbv O-3/d. (4) Forward trajectories from cloud outflow 
                         levels (postconvective conditions) put the ozone-producing air 
                         masses in eastern Brazil and the tropical Atlantic within 2-4 days 
                         and over the Atlantic, Africa, and the Indian Ocean in 6-8 days, 
                         Indeed, 3-4 days after the convective episode (September 30, 
                         1992), upper tropospheric levels in the Natal ozone sounding show 
                         an average increase of similar to 30 ppbv (3 Dobson units (DU) 
                         integrated) compared to the September 28 sounding. Our simulated 
                         net O-3 production rates in cloud outflow are a factor of 3 or 
                         more greater than those in air undisturbed by the storms, 
                         Integrated over the 8- to 16-km cloud outflow layer, the 
                         postconvection net O-3 production (similar to 5-6 DU over 8 days) 
                         accounts for similar to 25 of the excess O-3 (15-25 DU) over the 
                         South Atlantic. Comparison of TRACE A Brazilian ozonesondes and 
                         the frequency of deep convection with climatology [Kirchhoff et 
                         al., this issue] suggests that the late September 1992 conditions 
                         represented an unusually active period for both convection and 
                         upper tropospheric ozone formation.",
                 issn = "0148-0227 and 2156-2202",
                label = "9620",
           targetfile = "8682.pdf",
        urlaccessdate = "22 jan. 2021"
}


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