Scala, John R.Garstang, MichaelTao, Wei-kuoPickering, Kenneth E.Thompson, Anne M.Simpson, JoanneKirchhoff, Volker W. J. H.Browell, Edward V.Sachse, Glen W.Torres, Arnold L.Gregory, Gerald L.Rasmussen, R. A.Khalil, M. a K.2024-07-262024-07-261990-09-20Scala, John R., Michael Garstang, Wei-kuo Tao, Kenneth E. Pickering, Anne M. Thompson, Joanne Simpson, Volker W. J. H. Kirchhoff, et al. “Cloud Draft Structure and Trace Gas Transport.” Journal of Geophysical Research: Atmospheres 95, no. D10 (1990): 17015–30. https://doi.org/10.1029/JD095iD10p17015.https://doi.org/10.1029/JD095iD10p17015http://hdl.handle.net/11603/35032Field observations obtained during the second NASA Amazon Boundary Layer Experiment (ABLE 2B), and two-dimensional moist cloud model simulations are used to determine the dominant transport pathways within a continental tropical squall line. A surface-based network triangle provided the focus for a multi-instrumental sampling of the May 6, 1987, squall line which propagated through the central Amazon basin at a rate of 40–50 km h⁻¹. Extensive use is made of the vertical distribution of specific trace gases that are representative of the prestorm and poststorm environment. One-dimensional photochemical model results suggest the observed poststorm changes in ozone concentration can be attributed to convective transports rather than photochemical production. Two-dimensional cloud model results detail the dynamic and thermodynamic attributes of the simulated squall convection. The well-mixed moist troposphere in which the observed squall system developed may have hindered strong downdraft development. Parcel trajectory analyses are conducted to investigate the flow patterns of convective transports. A significant proportion (> 50%) of the air transported to the anvil region originated at or above 6 km, not from the boundary layer via undilute cores. The presence of a midlevel inflow and a strong melting layer at 5.5 km reduced the vertical development of the core updraft and aided in the maintenance of a rotor circulation. The predicted absence of more than one active cell in the model cloud field, the lack of a well-organized downdraft in the presence of model estimated net upward mass flux, and the initial wind profile suggest the May 6 squall line was unicell in character.16 pagesen-USThis work was written as part of one of the author's official duties as an Employee of the United States Government and is therefore a work of the United States Government. In accordance with 17 U.S.C. 105, no copyright protection is available for such works under U.S. Law.Public Domainhttps://creativecommons.org/publicdomain/mark/1.0/Text