Editorial Type:
Article
Article Type:
Research Article

Mobile Integrated Profiler System (MIPS) Observations of Low-Level Convergent Boundaries during IHOP

Haldun Karan University of Alabama in Huntsville, Huntsville, Alabama

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Kevin Knupp University of Alabama in Huntsville, Huntsville, Alabama

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Print Publication:
01 Jan 2006
DOI:
https://doi.org/10.1175/MWR3058.1
Page(s):
92–112
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Abstract

Characteristics of convergent boundary zones (CBZs) sampled by the Mobile Integrated Profiling System (MIPS) during the 2002 International H2O Project (IHOP_2002) are presented. The MIPS sensors (915-MHz wind profiler, 12-channel microwave profiling radiometer, ceilometer, and surface instrumentation) provide very fine temporal kinematic and thermodynamic profiles of the atmospheric boundary layer and CBZ properties, including enhanced 915-MHz backscatter within the CBZ updraft (equivalent to the radar fine line), a general increase in integrated water vapor within the updrafts of the CBZ, an increase in the convective boundary layer (CBL) depth, and changes in ceilometer backscatter that are typically coincident with arrival of cooler, moister air (the case for density current CBZ).

Three contrasting CBZs are analyzed. Convective initiation was associated with a slow-moving dryline as it passed over the MIPS on 19 June. Updrafts up to 6 m s−1 were measured, and the CBL attained its greatest depth within the CBZ. The CBZ in the other two cases were quite similar to density currents. The retrograding dryline of 18 June produced an enhancement in preexisting convection within 30 km of the MIPS. On 24 May, a shallow cold front, about 800 m deep, was sampled.

Corresponding author address: Haldun Karan, Dept. of Atmospheric Science, University of Alabama in Huntsville, NSSTC, 320 Sparkman Drive, Huntsville, AL 35805. Email: karan@nsstc.uah.edu

Abstract

Characteristics of convergent boundary zones (CBZs) sampled by the Mobile Integrated Profiling System (MIPS) during the 2002 International H2O Project (IHOP_2002) are presented. The MIPS sensors (915-MHz wind profiler, 12-channel microwave profiling radiometer, ceilometer, and surface instrumentation) provide very fine temporal kinematic and thermodynamic profiles of the atmospheric boundary layer and CBZ properties, including enhanced 915-MHz backscatter within the CBZ updraft (equivalent to the radar fine line), a general increase in integrated water vapor within the updrafts of the CBZ, an increase in the convective boundary layer (CBL) depth, and changes in ceilometer backscatter that are typically coincident with arrival of cooler, moister air (the case for density current CBZ).

Three contrasting CBZs are analyzed. Convective initiation was associated with a slow-moving dryline as it passed over the MIPS on 19 June. Updrafts up to 6 m s−1 were measured, and the CBL attained its greatest depth within the CBZ. The CBZ in the other two cases were quite similar to density currents. The retrograding dryline of 18 June produced an enhancement in preexisting convection within 30 km of the MIPS. On 24 May, a shallow cold front, about 800 m deep, was sampled.

Corresponding author address: Haldun Karan, Dept. of Atmospheric Science, University of Alabama in Huntsville, NSSTC, 320 Sparkman Drive, Huntsville, AL 35805. Email: karan@nsstc.uah.edu

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  • Angevine, W. M., S. K. Avery, and G. L. Kok, 1993: Virtual heat flux measurements from a boundary-layer profiler–RASS compared to aircraft measurements. J. Appl. Meteor, 32 , 1901–1907.

    • Search Google Scholar
    • Export Citation

  • Atkins, N. T., R. M. Wakimoto, and T. M. Weckwerth, 1995: Observations of the sea-breeze front during CaPE. Part II: Dual-Doppler and aircraft analysis. Mon. Wea. Rev, 123 , 944–969.

    • Search Google Scholar
    • Export Citation

  • Atkins, N. T., R. M. Wakimoto, and C. L. Ziegler, 1998: Observations of the finescale structure of a dryline during VORTEX 95. Mon. Wea. Rev, 126 , 525–550.

    • Search Google Scholar
    • Export Citation

  • Charba, J., 1974: Application of gravity current model to analysis of squall-line gust front. Mon. Wea. Rev, 102 , 140–156.

  • Cohn, S. A., and W. M. Angevine, 2000: Boundary layer height and entrainment zone thickness measured by lidars and wind-profiling radars. J. Appl. Meteor, 39 , 1233–1247.

    • Search Google Scholar
    • Export Citation

  • Cotton, W. R., and G. J. Tripoli, 1978: Cumulus convection in shear flow—Three-dimensional numerical experiments. J. Atmos. Sci, 35 , 1503–1521.

    • Search Google Scholar
    • Export Citation

  • Droegemeier, K. K., and R. B. Wilhelmson, 1987: Numerical simulation of thunderstorm outflow dynamics. Part I: Outflow sensitivity experiments and turbulence dynamics. J. Atmos. Sci, 44 , 1180–1210.

    • Search Google Scholar
    • Export Citation

  • Geerts, B., R. Damiani, and S. Haimov, 2006: Finescale vertical structure of a cold front as revealed by an airborne Doppler radar. Mon. Wea. Rev, 234 , 251–271.

    • Search Google Scholar
    • Export Citation

  • Grimsdell, A. W., and W. M. Angevine, 1998: Convective boundary layer height measurement with wind profilers and comparison to cloud base. J. Atmos. Oceanic Technol, 15 , 1331–1338.

    • Search Google Scholar
    • Export Citation

  • Grimsdell, A. W., and W. M. Angevine, 2002: Observations of the afternoon transition of the convective boundary layer. J. Appl. Meteor, 41 , 3–11.

    • Search Google Scholar
    • Export Citation

  • Güldner, J., and D. Spänkuch, 2001: Remote sensing of the thermodynamic state of the atmospheric boundary layer by ground-based microwave radiometry. J. Atmos. Oceanic Technol, 18 , 925–933.

    • Search Google Scholar
    • Export Citation

  • Hane, C. E., R. M. Rabin, T. M. Crawford, H. B. Bluestein, and M. E. Baldwin, 2002: A case study of severe storm development along a dryline within a synoptically active environment. Part II: Multiple boundaries and convective initiation. Mon. Wea. Rev, 130 , 900–920.

    • Search Google Scholar
    • Export Citation

  • Hogg, D. C., F. O. Guiraud, J. B. Snider, M. T. Decker, and E. R. Westwater, 1983: A steerable dual-channel microwave radiometer for measurement of water vapor and liquid in the troposphere. J. Appl. Meteor, 22 , 789–806.

    • Search Google Scholar
    • Export Citation

  • Kingsmill, D. E., and N. A. Crook, 2003: An observational study of atmospheric bore formation from colliding density currents. Mon. Wea. Rev, 131 , 2985–3002.

    • Search Google Scholar
    • Export Citation

  • Martner, B. E., 1997: Vertical velocities in a thunderstorm gust front and outflow. J. Appl. Meteor, 36 , 615–622.

  • May, P. T., 1999: Thermodynamic and vertical velocity structure of two gust fronts observed with a wind profiler/RASS during MCTEX. Mon. Wea. Rev, 127 , 1796–1807.

    • Search Google Scholar
    • Export Citation

  • Murphey, H. V., R. M. Wakimoto, C. Flamant, and D. E. Kingsmill, 2006: Dryline on 19 June 2002 during IHOP. Part I: Airborne Doppler and LEANDRE II analyses of the thin line structure and convective initiation. Mon. Wea. Rev, 134 , 406–430.

    • Search Google Scholar
    • Export Citation

  • Neiman, P. J., F. M. Ralph, R. L. Weber, T. Uttal, L. B. Nance, and D. H. Levinson, 2001: Observations of nonclassical frontal propagation and frontally forced gravity waves adjacent to steep topography. Mon. Wea. Rev, 129 , 2633–2659.

    • Search Google Scholar
    • Export Citation

  • Parsons, D. B., M. A. Shapiro, R. M. Hardesty, R. J. Zamora, and J. M. Intrieri, 1991: The finescale structure of a west Texas dryline. Mon. Wea. Rev, 119 , 1242–1258.

    • Search Google Scholar
    • Export Citation

  • Ralph, F. M., P. J. Neiman, and T. L. Keller, 1999: Deep-tropospheric gravity waves created by leeside cold fronts. J. Atmos. Sci, 56 , 2986–3009.

    • Search Google Scholar
    • Export Citation

  • Rasmussen, E. N., S. Richardson, J. M. Straka, P. M. Markowski, and D. O. Blanchard, 2000: The association of significant tornadoes with a baroclinic boundary on 2 June 1995. Mon. Wea. Rev, 128 , 174–191.

    • Search Google Scholar
    • Export Citation

  • Reuter, G. W., and M. K. Yau, 1987: Mixing mechanisms in cumulus congestus clouds. Part II: Numerical simulations. J. Atmos. Sci, 44 , 798–827.

    • Search Google Scholar
    • Export Citation

  • Rogers, R. R., W. L. Ecklund, D. A. Carter, K. S. Gage, and S. A. Ethier, 1993: Research applications of a boundary-layer wind profiler. Bull. Amer. Meteor. Soc, 74 , 567–580.

    • Search Google Scholar
    • Export Citation

  • Rotunno, R., J. B. Klemp, and M. L. Weisman, 1988: A theory for strong, long-lived squall lines. J. Atmos. Sci, 45 , 463–485.

  • Schroeder, J. A., 1990: A comparison of temperature soundings obtained from simultaneous radiometrics, radio-acoustic, and rawinsonde measurements. J. Atmos. Oceanic Technol, 7 , 495–503.

    • Search Google Scholar
    • Export Citation

  • Solheim, F., J. R. Godwin, E. R. Westwater, Y. Han, S. J. Keihm, K. Marsh, and R. Ware, 1998: Radiometric profiling of temperature, water vapor and cloud liquid water using various inversion methods. Radio Sci, 33 , 393–404.

    • Search Google Scholar
    • Export Citation

  • Wakimoto, R. M., 1982: The life cycle of thunderstorm gust fronts as viewed with Doppler radar and rawinsonde data. Mon. Wea. Rev, 110 , 1060–1082.

    • Search Google Scholar
    • Export Citation

  • Wakimoto, R. M., H. V. Murphey, E. Browell, and S. V. Asmail, 2006: The “triple point” on 24 May 2002 during IHOP. Part I: Airborne Doppler and LASE analyses of the frontal boundaries and convective initiation. Mon. Wea. Rev, , in press.

    • Search Google Scholar
    • Export Citation

  • Weckwerth, T. M., and D. B. Parsons, 2006: A review of convection initiation and motivation for IHOP_2002. Mon. Wea. Rev, 134 , 5–22.

  • Weckwerth, T. M., T. W. Horst, and J. W. Wilson, 1999: An observational study of the evolution of horizontal convective rolls. Mon. Wea. Rev, 127 , 2160–2179.

    • Search Google Scholar
    • Export Citation

  • Weckwerth, T. M., and Coauthors, 2004: An overview of the International H2O project (IHOP_2002) and some preliminary highlights. Bull. Amer. Meteor. Soc, 85 , 253–277.

    • Search Google Scholar
    • Export Citation

  • Weisman, L. M., and R. Rotunno, 2004: “A theory for strong long-lived squall lines” revisited. J. Atmos. Sci, 61 , 361–382.

  • Weiss, C. C., and H. B. Bluestein, 2002: Airborne pseudo–dual Doppler analysis of a dryline–outflow boundary intersection. Mon. Wea. Rev, 130 , 1207–1226.

    • Search Google Scholar
    • Export Citation

  • White, A. B., C. W. Fairall, and D. W. Thomson, 1991: Radar observations of humidity variability in and above the marine atmospheric boundary layer. J. Atmos. Oceanic Technol, 8 , 639–658.

    • Search Google Scholar
    • Export Citation

  • Wilson, J. W., and W. E. Schreiber, 1986: Initiation of convective storms at radar-observed boundary-layer convergence lines. Mon. Wea. Rev, 114 , 2516–2536.

    • Search Google Scholar
    • Export Citation

  • Wilson, J. W., and D. L. Megenhardt, 1997: Thunderstorm initiation, organization, and lifetime associated with Florida boundary layer convergence lines. Mon. Wea. Rev, 125 , 1507–1525.

    • Search Google Scholar
    • Export Citation

  • Wilson, J. W., T. M. Weckwerth, J. Vivekanandan, R. M. Wakimoto, and R. W. Russell, 1994: Boundary layer clear-air radar echoes: Origin of echoes and accuracy of derived winds. J. Atmos. Oceanic Technol, 11 , 1184–1206.

    • Search Google Scholar
    • Export Citation

  • Wurman, J., 2002: The multiple-vortex structure of a tornado. Wea. Forecasting, 17 , 473–505.

  • Ziegler, C. L., and C. E. Hane, 1993: An observational study of a dryline. Mon. Wea. Rev, 121 , 1134–1151.

  • Ziegler, C. L., and E. N. Rasmussen, 1998: The initiation of moist convection at the dryline: Forecasting issues from a case study perspective. Wea. Forecasting, 13 , 1106–1131.

    • Search Google Scholar
    • Export Citation

  • Ziegler, C. L., W. J. Martin, R. A. Pielke, and R. L. Walko, 1995: A modeling study of the dryline. J. Atmos. Sci, 52 , 263–285.

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