This paper benefited from interactions with several people, which included supplying the authors with impressions of GATE and COARE, and references to the relevant literature. Nearly daily conversations with David Jorgensen, Tom Matejka, and Bradley Smull helped germinate and nurture arguments in this paper; also Peter Hildebrand, Robert Houze Jr., Joanne Simpson, Wei-Kuo Tao, Gary Barnes, Xiaoqing Wu, and Garpee Barleszi provided encouragement and useful information. John Dougherty provided the radar composites we used for tracking systems away from the ship radars and for Figs. 1–9. William Skamarock, Thomas Matejka, Gary Barnes, David Parsons, and two anonymous reviewers made useful comments on the paper, contributing to its clarity. This work was made possible by the dedication and hard work of the flight and science crews of the NOAA P3s, the NCAR Electra, and the NASA DC-8, and the support people in Townsville and Honiara during TOGA COARE, as well as the radiosonde crews on ships and islands. LeMone and Trier acknowledge the support of NCAR and NSF Grant ATM921550; Zipser, NASA Grant NAG5-1569 and partial support from NCAR during the summer months.
Alexander, G. D., and G. S. Young, 1992: The relationship between EMEX mesoscale precipitation feature properties and their environmental characteristics. Mon. Wea. Rev.,120, 554–564.
Arkell, R., and R. Hudlow, 1977: GATE International Meteorological Radar Atlas. Center for Experiment Design and Data Analysis, NOAA, 222 pp. [Available from Superindent of Documents, U.S. Govt. Printing Office, Washington, DC 20402.].
Asai, T., 1970: Stability of a plane parallel flow with variable vertical shear and unstable stratification. J. Meteor. Soc. Japan,48, 129–139.
Balaji, V., J.-L. Redelsperger, and G. P. Klaasen, 1993: Mechanisms for the mesoscale organization of tropical cloud clusters in GATE Phase III. Part I: Shallow cloud bands. J. Atmos. Sci.,50, 3571–3589.
Barnes, G. M., and K. Sieckman, 1984: The environment of fast- and slow-moving tropical mesoscale convective cloud lines. Mon. Wea. Rev.,112, 1782–1794.
Betts, A. K., R. W. Grover, and M. W. Moncrieff, 1976: Structure and motion of tropical squall-lines over Venezuela. Quart. J. Roy. Meteor. Soc.,102, 395–404.
Blanchard, D. O., 1990: Mesoscale convective patterns of the southern high plains. Bull. Amer. Meteor. Soc.,71, 994–1005.
Bluestein, H. B., and M. H. Jain, 1985: Formation of mesoscale lines of precipitation: Severe squall lines in Oklahoma during the spring. J. Atmos. Sci.,42, 1711–1732.
——, G. T. Marx, and M. H. Jain, 1987: Formation of mesoscale lines of precipitation: Non-severe squall lines in Oklahoma during the spring. Mon. Wea. Rev.,115, 2719–2727.
Bolton, D., 1980: The computation of equivalent potential temperature. Mon. Wea. Rev.,108, 1046–1053.
Carbone, R. E., 1982: A severe frontal rainband. Part I: Stormwide hydrodynamic structure. J. Atmos. Sci.,39, 258–279.
Chisholm, A. J., and J. H. Renick, 1972: The kinematics of multicell and supercell Alberta hailstorms. Hail Studies Report No. 72-2, Alberta Hail Studies, Research Council of Alberta, 53 pp.
Clark, T. L., T. Hauf, and J. P. Kuettner, 1986: Convective-forced internal gravity waves: Results from two-dimensional experiments. Quart. J. Roy. Meteor. Soc.,112, 899–926.
Cole, H. L., and E. Miller, 1995: A correction for low-level radiosonde temperature. Preprints, Ninth Symp. on Meteorological Observations and Instrumentation, Charlotte, NC, Amer. Meteor. Soc., 32–39.
Dickey, J. A., 1996: Analysis of the atmospheric mixed layer over the western Pacific warm pool. Dept. of Atmos. Sci. Paper No. 609, Colorado State University, 84 pp. [Available from Dept. of Atmospheric Science, Colorado State University, Fort Collins, CO 80523.].
Dudhia, J., and M. W. Moncrieff, 1987: A numerical simulation of quasi-stationary tropical convective bands. Quart. J. Roy. Meteor. Soc.,113, 929–967.
Etling, D., and R. A. Brown, 1993: Roll vortices in the planetary boundary layer: A review. Bound.-Layer Meteor.,65, 215–248.
Fairall, C. W., E. F. Bradley, D. P. Rogers, J. B. Edson, and G. S. Young, 1996: Bulk parameterization of air–sea fluxes for the Tropical Ocean Global Atmosphere Coupled Ocean–Atmosphere Response Experiment. J. Geophys. Res.,101, 3747–3765.
Fitzjarrald, D. R., and M. Garstang, 1981: Vertical structure of the tropical boundary layer. Mon. Wea. Rev.,109, 1512–1526.
Gamache, J. F., and R. A. Houze Jr., 1982: Mesoscale air motions associated with a tropical squall line. Mon. Wea. Rev.,110, 118–135.
——, and ——, 1983: Water budget of a mesoscale convective system in the tropics. J. Atmos. Sci.,40, 1835–1850.
——, and ——, 1985: Further analysis of the composite wind and thermodynamic structure of the 12 September GATE squall line. Mon. Wea. Rev.,113, 1241–1259.
Geldmeier, M. F., and G. M. Barnes, 1997: The “footprint” under a decaying tropical mesoscale convective system. Mon. Wea. Rev.,125, 2879–2895.
Halverson, J. B., B. S. Ferrier, J. Simpson, and W.-K. Tao, 1996:Two-dimensional numerical modeling investigation of the February 11, 1993 TOGA COARE mesoscale convective system. Preprints, Seventh Conf. on Mesoscale Processes, Reading, United Kingdom, Amer. Meteor. Soc., 165–167.
Hildebrand, P., 1998: Shear-parallel moist convection over the tropical ocean: A case study from 18 February 1993 TOGA COARE. Mon. Wea. Rev.,126, 192–216.
——, W.-C. Lee, C. A. Walther, C. Frush, M. Randall, E. Loew, R. Neitzel, R. Parsons, J. Testud, F. Baudin, and A. LeCornec, 1996: The ELDORA/ASTRAIA Airborne Doppler Weather Radar: High-resolution observations from TOGA-COARE. Bull. Amer. Meteor. Soc.,77, 213–232.
Hobbs, P. A., and P. O. G. Perrson, 1982: The mesoscale and microscale structure and organization of clouds and precipitation in midlatitude cyclones. Part V: The substructure of narrow cold-frontal rainbands. J. Atmos. Sci.,39, 280–295.
Houze, R. A., Jr., 1977: Structure and dynamics of a tropical squall-line system. Mon. Wea. Rev.,105, 1540–1567.
——, and C.-P. Cheng, 1977: Radar characteristics of tropical convection observed during GATE. Mon. Wea. Rev.,105, 964–980.
——, and E. N. Rappaport, 1984: Air motions and precipitation of an early summer squall line over the eastern tropical Atlantic. J. Atmos. Sci.,41, 553–574.
——, B. F. Smull, and P. Dodge, 1990: Mesoscale organization of springtime rainstorms in Oklahoma. Mon. Wea. Rev.,118, 613–654.
Hu, J., and G. M. Barnes, 1994: A fast-moving MCS parallel to the environmental shear over the oceanic warm pool. Preprints, Sixth Conf. on Mesoscale Processes, Portland, OR, Amer. Meteor. Soc., 33–35.
Johnson, R. H., and M. E. Nicholls, 1983: A composite analysis of the boundary layer accompanying a tropical squall line. Mon. Wea. Rev.,111, 308–319.
Jorgensen, D. P., M. A. LeMone, and S. B. Trier, 1997: Structure and evolution of the 22 February 1993 TOGA COARE squall line: Aircraft observations of precipitation, circulation, and surface energy fluxes. J. Atmos. Sci.,54, 1961–1985.
Keenan, T. D., and R. E. Carbone, 1992: A preliminary morphology of precipitation systems in tropical northern Australia. Quart. J. Roy. Meteor. Soc.,118, 283–326.
Kingsmill, D. E., and R. A. Houze Jr., 1998a: Inflow and outflow characteristics of convection in TOGA COARE. Part I: Velocity structures. Quart. J. Roy. Meteor. Soc., in press.
——, and ——, 1998b: Inflow and outflow characteristics of convection in TOGA COARE. Part II: Thermodynamics. Quart. J. Roy. Meteor. Soc., in press.
Koch, S. E., 1984: The role of an apparent mesoscale frontogenetic circulation in squall line initiation. Mon. Wea. Rev.,112, 2090–2111.
Krishnamurti, T. N., V. Wong, H. L. Pan, G. Van Dam, and D. McClellan, 1976: Sea surface temperatures for GATE. Report No. 76-3, Dept. of Meteorology, The Florida State University, 268 pp. [Available from Dept. of Meteorology, The Florida State University, Tallahassee, FL 32306.].
Lau, K.-M., L. Peng, C.-H. Sui, and T. Nakazawa, 1989: Dynamics of super cloud clusters, westerly wind burst, 30–60 day oscillation, and ENSO: An unified view. J. Meteor. Soc. Japan,67, 205–219.
Leary, C. A., 1984: Precipitation structure of the cloud clusters in a tropical easterly wave. Mon. Wea. Rev.,112, 313–325.
——, and R. A. Houze Jr., 1979a: The structure and evolution of convection in a tropical cloud cluster. J. Atmos. Sci.,36, 437–457.
——, and ——, 1979b: Melting and evaporation of hydrometeors in precipitation from the anvil clouds of deep tropical convection. J. Atmos. Sci.,36, 669–679.
LeMone, M. A., 1983: Momentum transport by a line of cumulonimbus. J. Atmos. Sci.,40, 1815–1834.
——, and R. J. Meitin, 1981: Mesoscale motion fields associated with a slowly moving GATE convective band. J. Atmos. Sci.,38, 1725–1750.
——, and M. W. Moncrieff, 1994: Momentum and mass transport by convective bands: Comparisons of highly idealized dynamical models to observations. J. Atmos. Sci.,51, 281–305.
——, G. M. Barnes, E. J. Szoke, and E. J. Zipser, 1984a: The tilt of the leading edge of mesoscale tropical convective lines. Mon. Wea. Rev.,112, 512–519.
——, ——, and E. J. Zipser 1984b: Momentum fluxes by lines of cumulonimbus over the tropical oceans. J. Atmos. Sci.,41, 1914–1932.
Lewis, S. A., M. A. LeMone, and D. P. Jorgensen, 1998: Evolution and dynamics of a late-stage squall line that occurred on 20 February 1993, during TOGA COARE. Mon. Wea. Rev.,126, 3189–3212.
Lin, X., and R. H. Johnson, 1996: Kinematic and thermodynamic characteristics of the flow over the western Pacific warm pool during TOGA COARE. J. Atmos. Sci.,53, 695–715.
Lucas, C., and E. J. Zipser, 1996: The variability of vertical profiles of wind, temperautre, and moisture during TOGA COARE. Preprints, Seventh Conf. on Mesoscale Processes, Reading, United Kingdom, Amer. Meteor. Soc., 125–127.
——, ——, and M. A. LeMone, 1994: Vertical velocity in oceanic convection off tropical Australia. J. Atmos. Sci.,51, 3183–3103.
Madden, R. A., and P. Julian, 1972: Description of global scale circulation cells in the tropics with a 40–50 day period. J. Atmos. Sci.,29, 1109–1123.
Malkus, J. S., 1958: On the structure of the trade wind moist layer. Papers Phys. Ocean Meteor. 13, Woods Hole Oceanographic Institution, 47 pp. [Available from Woods Hole Oceanographic Institution, Woods Hole, MA 02543.].
——, and H. Riehl, 1964: Cloud structure and distributions over the tropical Pacific Ocean. Tellus,16, 275–287.
Mapes, B. E., 1993: Gregarious tropical convection. J. Atmos. Sci.,50, 2026–2037.
——, and R. A. Houze Jr., 1993: Cloud clusters and superclusters over the oceanic warm pool. Mon. Wea. Rev.,121, 1398–1415.
——, and P. Zuidema, 1996: Radiative–dynamical consequenes of dry tongues in the tropical troposphere. J. Atmos. Sci.,53, 620–638.
Martin, D. W., and A. J. Schreiner, 1981: Characteristics of west African and east Atlantic cloud clusters: A survey from GATE. Mon. Wea. Rev.,109, 1671–1688.
Matejka, T., and G. Stossmeister, 1986: Convective–mesoscale interaction in a squall line. Preprints, 23d Conf. on Radar Meteorology and Conf. on Cloud Physics, Vol. III, Snowmass, CO, Amer. Meteor. Soc., J135–J138.
——, and S. A. Lewis, 1997: Improving research aircraft navigation by incorporating INS and GPS information in a variational solution. J. Atmos. Oceanic Technol.,14, 495–511.
Moncrieff, M. W., 1978: The dynamical structure of two-dimensional steady convection in constant vertical shear. Quart. J. Roy. Meteor. Soc.,104, 543–567.
——, 1981: A theory of organised steady convection and its transport properties. Quart. J. Roy. Meteor. Soc.,107, 29–50.
——, 1992: Organised mesoscale convective systems: Archetypal dynamical models, mass and momentum flux theory, and parametrisation. Quart. J. Roy. Meteor. Soc.,118, 819–850.
——, and J. S. A. Green, 1972: The propagation and transfer properties of steady convective overturning in shear. Quart. J. Roy. Meteor. Soc.,98, 336–352.
——, and M. J. Miller, 1976: The dynamics and simulation of tropical cumulonimbus and squall lines. Quart. J. Roy. Meteor. Soc.,102, 373–394.
Nakazawa, T., 1988: Tropical superclusters within intraseasonal variations over the western Pacific. J. Meteor. Soc. Japan,66, 823–839.
Newton, C. W., 1950: Structure and mechanism of the prefrontal squall line. J. Meteor.,7, 210–222.
——, 1963: Dynamics of severe convective storms. Severe Local Storms, Meteor. Monogr., No. 27, Amer. Meteor. Soc., 33–58.
Nicholls, M. E., R. H. Johnson, and W. R. Cotton, 1988: The sensitivity of two-dimensional simulations of tropical squall lines to environmental profiles. J. Atmos. Sci.,45, 3626–3649.
Nicholls, S., and M. A. LeMone, 1980: The fair weather boundary layer in GATE: The relationship of subcloud fluxes and structure to the distribution and enhancement of cumulus clouds. J. Atmos. Sci.,37, 2051–2067.
——, ——, and G. Sommeria, 1982: The simulation of a fair weather marine boundary layer in GATE using a three dimensional model. Quart. J. Roy. Meteor. Soc.,108, 167–190.
Pandya, R. E., and D. R. Durran, 1996: The influence of convectively generated thermal forcing on the mesoscale circulation around squall lines. J.Atmos. Sci.,53, 2924–2951.
Pestaina-Haynes, M., and G. L. Austin, 1976: Comparison between maritime tropical (GATE and Barbados) and continental mid-latitude (Montreal) precipitation lines. J. Appl. Meteor.,15, 1077–1082.
Reed, R. J., D. C. Norquist, and E. E. Recker, 1977: The structure and properties of African wave disturbances as observed during Phase III of GATE. Mon. Wea. Rev.,105, 317–333.
Rickenbach, T. M., and S. A. Rutledge, 1998: Convection in TOGA COARE: Horizontal scale, morphology, and rainfall production. J. Atmos. Sci.,55, 2715–2729.
Robe, F. R., 1996a: Sea, sun, and shear: A recipe for precipitating convection, tropical rainbands, and hurricane spiral arms. Ph.D. dissertation, Massachusetts Institute of Technology, 242 pp. [Available from MIT Libraries, Rm. 14-0551, Cambridge, MA 02139-4307.].
——, 1996b: Sea, sun, and shear: A recipe for tropical rainbands. Preprints, Seventh Conf. on Mesoscale Processes, Amer. Meteor. Soc., 174–175.
Rotunno, R., J. B. Klemp, and M. L. Weisman, 1988: A theory for strong, long-lived squall lines. J. Atmos. Sci.,45, 463–485.
Skamarock, W. C., S. B. Trier, and M. A. LeMone, 1996: The dynamics of slow and fast-moving convective lines in TOGA COARE. Preprints, Seventh Conf. on Mesoscale Processes, Reading, United Kingdom, Amer. Meteor. Soc., 301–303.
Smull, B. F., T. J. Matejka, and M. A. LeMone, 1996: Airflow trajectories within a slow-moving convective system observed during TOGA-COARE. Preprints, Seventh Conf. on Mesoscale Processes, Reading, United Kingdom, Amer. Meteor. Soc., 289–291.
Srivastiva, R. C., T. J. Matejka, and T. J. Lorello, 1986: Doppler radar study of the trailing anvil region associated with a squall line. J. Atmos. Sci.,43, 356–377.
Sun, W.-Y., 1978: Stability analysis of deep cloud streets. J. Atmos. Sci.,35, 466–483.
Thorpe, A. J., M. J. Miller, and M. W. Moncrieff, 1982: Two-dimensional convection in non-constant shear: A model of mid-latitude squall lines. Quart. J. Roy. Meteor. Soc.,108, 739–762.
Trier, S. B., D. B. Parsons, and J. H. E. Clark, 1991: Environment and evolution of a cold-frontal mesoscale convective system. Mon. Wea. Rev.,119, 2429–2455.
——, W. C. Skamarock, M. A. LeMone, D. B. Parsons, and D. P. Jorgensen, 1996: Structure and evolution of the 22 February 1993 TOGA-COARE squall line: Numerical simulations. J. Atmos. Sci.,53, 2861–2886.
——, ——, and M. A. LeMone, 1997: Structure and evolution of the 22 Feburary 1993 TOGA COARE squall line: Organization mechanisms inferred from numerical simulation. J. Atmos. Sci.,54, 386–407.
——, M. A. LeMone, and W. C. Skamarock, 1998: Effect of three-dimensional structure on the stormwide horizontal accelerations and momentum budget or a simulated squall line. Mon. Wea. Rev.,126, 2580–2598.
Webster, P. J., and R. Lukas, 1992: TOGA COARE: The Coupled Ocean–Atmosphere Response Experiment. Bull. Amer. Meteor. Soc.,73, 1377–1416.
Wei, T., and R. A. Houze Jr., 1987: The GATE squall line of 9–10 August 1974. Adv. Atmos. Sci.,4, 85–92.
Weisman, M. L., and J. B. Klemp, 1982: The dependence of numerically simulated convective storms on vertical wind shear and buoyancy. Mon. Wea. Rev.,110, 504–520.
——, and ——, 1984: The structure and classification of numerically simulated convective storms in directionally varying wind shears. Mon. Wea. Rev.,112, 2479–2498.
——, and ——, 1986: Characteristics of convective storms. Mesoscale Meteorology and Forecasting, P. S. Ray, Ed., Amer. Meteor. Soc., 331–358.
Yuter, S. E., R. A. Houze Jr., B. F. Smull, F. D. Marks Jr., J. R. Daugherty, and S. R. Brodzik, 1995: TOGA COARE aircraft mission summary images: An electronic atlas. Bull. Amer. Meteor. Soc.,76, 319–328.
Zipser, E. J., and M. A. LeMone, 1980: Cumulonimbus and vertical events in GATE. Part II: Synthesis and model core structure. J. Atmos. Sci.,37, 2458–2469.
——, and R. H. Johnson, 1998: Systematic errors in radiosonde humidities. A global problem? Preprints, 10th Symp. on Meteorological Observations and Instrumentation, Phoenix, AZ, Amer. Meteor. Soc., 72–73.
——, R. J. Meitin, and M. A. LeMone, 1981: Mesoscale motion fields associated with a slowly moving GATE convective band. J. Atmos. Sci.,38, 1725–1750.
——, Y.-L. Chen, and E. J. Szoke, 1983: On the generation of heavy precipitation with the anvil system of a tropical squall line. Proc. 21st Conf. on Radar Meteorology, Edmonton, AB, Canada, Amer. Meteor. Soc., 50–56.