• Armijo, L. 1969. A theory for the determination of wind and precipitation velocities with Doppler radars. J. Atmos. Sci. 26:570573.

  • Brandes, E. A. 1984. Relationships between radar-derived thermodynamic variables and tornadogenesis. Mon. Wea. Rev. 112:10331052.

  • Cai, H. and R. M. Wakimoto. 2001. Retrieved pressure field and its influence on the propagation of a supercell thunderstorm. Mon. Wea. Rev. 129:26952713.

    • Search Google Scholar
    • Export Citation
  • Chen, C-S. 1991. A numerical study of a squall line over the Taiwan strait during TAMEX IOP2. Mon. Wea. Rev. 119:26772698.

  • 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. 44:11801210.

    • Search Google Scholar
    • Export Citation
  • Fovell, R. G. and Y. Ogura. 1988. Numerical simulation of a midlatitude squall line in two dimensions. J. Atmos. Sci. 45:38463879.

  • Gal-Chen, T. 1978. A method for the initialization of the anelastic equations: Implications for matching models with observations. Mon. Wea. Rev. 106:587606.

    • Search Google Scholar
    • Export Citation
  • Gal-Chen, T. 1982. Errors in fixed and moving frame of reference: Application for conventional and Doppler radar analysis. J. Atmos. Sci. 39:22792300.

    • Search Google Scholar
    • Export Citation
  • Gal-Chen, T. and R. A. Kropfli. 1984. Buoyancy and pressure perturbations derived from dual-Doppler radar observations of the planetary boundary layer: Applications for matching models with observations. J. Atmos. Sci. 41:30073020.

    • Search Google Scholar
    • Export Citation
  • Hane, C. E. and P. S. Ray. 1985. Pressure and buoyancy fields derived from Doppler radar data in a tornadic thunderstorm. J. Atmos. Sci. 42:1835.

    • Search Google Scholar
    • Export Citation
  • Hane, C. E., R. B. Wilhelmson, and T. Gal-Chen. 1981. Retrieval of thermodynamic variables within deep convective clouds: Experiments in three dimensions. Mon. Wea. Rev. 109:564576.

    • Search Google Scholar
    • Export Citation
  • Hauser, D., F. Roux, and P. Amayenc. 1988. Comparison of two methods for the retrieval of thermodynamic and microphysical variables from Doppler radar measurements: Application to the case of a tropical squall line. J. Atmos. Sci. 45:12851303.

    • Search Google Scholar
    • Export Citation
  • Klemp, J. B. and R. B. Wilhelmson. 1978. The simulation of three-dimensional convective storm dynamics. J. Atmos. Sci. 35:10701096.

  • LeMone, M. A., G. M. Barnes, and E. J. Zipser. 1984. Momentum flux by lines of cumulonimbus over the tropical oceans. J. Atmos. Sci. 41:19141932.

    • Search Google Scholar
    • Export Citation
  • Lin, Y-J., T-C. Chen Wang, and J. H. Lin. 1986. Pressure and temperature perturbations within a squall-line thunderstorm derived from SESAME dual-Doppler data. J. Atmos. Sci. 43:23022327.

    • Search Google Scholar
    • Export Citation
  • Lin, Y-J., T-C. Chen Wang, R. Pasken, H. Shen, and Z-S. Deng. 1990. Characteristics of a subtropical squall line determined from TAMEX dual-Doppler data. Part II: Dynamic and thermodynamic structures and momentum budgets. J. Atmos. Sci. 47:23822399.

    • Search Google Scholar
    • Export Citation
  • Liou, Y-C. 2001. The derivation of absolute potential temperature perturbations and pressure gradients from wind measurements in three-dimensional space. J. Atmos. Oceanic Technol. 18:577590.

    • Search Google Scholar
    • Export Citation
  • Mohr, C. G., L. J. Miller, R. L. Vaughn, and H. W. Frank. 1986. The merges of mesoscale dataset into a common Cartesian format for efficient and systematic analysis. J. Atmos. Oceanic Technol. 3:143161.

    • Search Google Scholar
    • Export Citation
  • Parsons, D. B., C. G. Mohr, and T. Gal-Chen. 1987. A severe frontal rainband. Part III: Derived thermodynamic structure. J. Atmos. Sci. 44:16151631.

    • Search Google Scholar
    • Export Citation
  • Ray, P. S., C. L. Ziegler, and W. Bumgarner. 1980. Single- and multiple-Doppler radar observations of tornadic storms. Mon. Wea. Rev. 108:16071625.

    • Search Google Scholar
    • Export Citation
  • Rotunno, R., J. B. Klemp, and M. L. Weisman. 1988. A theory for strong, long-lived squall line. J. Atmos. Sci. 45:463485.

  • Roux, F. 1985. Retrieval of thermodynamic fields from multiple-Doppler radar data using the equations of motion and the thermodynamic equation. Mon. Wea. Rev. 113:21422157.

    • Search Google Scholar
    • Export Citation
  • Roux, F. 1988. The West African squall line observed on 23 June 1981 during COPT 81: Kinematics and thermodynamics of the convective region. J. Atmos. Sci. 45:406426.

    • Search Google Scholar
    • Export Citation
  • Roux, F. and J. Sun. 1990. Single-Doppler observations of a West African squall line on 27–28 May 1981 during COPT 81: Kinematics, thermodynamics and water budget. Mon. Wea. Rev. 118:18261854.

    • Search Google Scholar
    • Export Citation
  • Roux, F., V. Marecal, and D. Hauser. 1993. The 12/13 January 1998 narrow cold-frontal rainband observed during MFDP/FRONTS 87. Part I: Kinematics and thermodynamics. J. Atmos. Sci. 50:951974.

    • Search Google Scholar
    • Export Citation
  • Sun, J. and F. Roux. 1988. Thermodynamic structure of the trailing stratiform regions of two West African squall lines. Ann. Geophys. 6:659670.

    • Search Google Scholar
    • Export Citation
  • Sun, J. and R. A. Houze Jr.. 1992. Validation of a thermodynamic retrieval technique by application to a simulated squall line with trailing stratiform precipitation. Mon. Wea. Rev. 120:10031018.

    • Search Google Scholar
    • Export Citation
  • Sun, J. and N. A. Crook. 1996. Comparison of thermodynamic retrieval by the adjoint method with the traditional retrieval method. Mon. Wea. Rev. 124:308324.

    • Search Google Scholar
    • Export Citation
  • Tao, W-K., J. Simpson, and S-T. Soong. 1991. Numerical simulation of a subtropical squall line over the Taiwan strait. Mon. Wea. Rev. 119:26992723.

    • Search Google Scholar
    • Export Citation
  • Wang, T-C. C., Y-J. Lin, R. Pasken, and H. Shen. 1990. Characteristics of a subtropical squall line determined from TAMEX dual-Doppler data. Part I: Kinematic structure. J. Atmos. Sci. 47:23572381.

    • Search Google Scholar
    • Export Citation
  • Yu, C-K., B. J-D. Jou, and D. P. Jorgensen. 2001. Retrieved thermodynamic structure of a subtropical, orographically influenced, quasi-stationary convective line. Mon. Wea. Rev. 129:10991116.

    • Search Google Scholar
    • Export Citation
All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 199 30 1
PDF Downloads 25 17 2

A Three-Dimensional Variational Approach for Deriving the Thermodynamic Structure Using Doppler Wind Observations—An Application to a Subtropical Squall Line

View More View Less
  • 1 Department of Atmospheric Sciences, National Central University, Chung-Li, Taiwan
Restricted access

Abstract

A newly designed retrieval scheme based on three-dimensional variational analysis is used to extract the thermodynamic field of a weather system from Doppler wind measurements. As compared with the traditional retrieval method, with this formulation the proposed scheme is able to find a set of optimal solutions for the pressure and buoyancy perturbations that, in the least squares sense, will simultaneously satisfy three momentum equations and a simplified thermodynamic equation. Therefore, the products of the retrieval are the complete thermodynamic fields in three dimensions. To test the performance of this method in real cases, it is applied to the analysis of a subtropical squall line. The required wind data were synthesized by two C-band Doppler radars during the 1987 Taiwan Area Mesoscale Experiment (TAMEX). The emphasis of this study is devoted to an examination of the validity of the retrieved thermodynamic structure, especially along the vertical direction. The results indicate that the distributions of the retrieved thermodynamic parameters are consistent with the kinematic structure and can be reasonably explained by the conceptual model of a squall line. Evidence is collected that strongly supports the validity of the derived thermodynamic structure. Thus, the applicability of this new retrieval scheme is demonstrated.

Corresponding author address: Dr. Yu-Chieng Liou, Department of Atmospheric Sciences, National Central University, Chung-Li, 320, Taiwan. tyliou@atm.ncu.edu.tw

Abstract

A newly designed retrieval scheme based on three-dimensional variational analysis is used to extract the thermodynamic field of a weather system from Doppler wind measurements. As compared with the traditional retrieval method, with this formulation the proposed scheme is able to find a set of optimal solutions for the pressure and buoyancy perturbations that, in the least squares sense, will simultaneously satisfy three momentum equations and a simplified thermodynamic equation. Therefore, the products of the retrieval are the complete thermodynamic fields in three dimensions. To test the performance of this method in real cases, it is applied to the analysis of a subtropical squall line. The required wind data were synthesized by two C-band Doppler radars during the 1987 Taiwan Area Mesoscale Experiment (TAMEX). The emphasis of this study is devoted to an examination of the validity of the retrieved thermodynamic structure, especially along the vertical direction. The results indicate that the distributions of the retrieved thermodynamic parameters are consistent with the kinematic structure and can be reasonably explained by the conceptual model of a squall line. Evidence is collected that strongly supports the validity of the derived thermodynamic structure. Thus, the applicability of this new retrieval scheme is demonstrated.

Corresponding author address: Dr. Yu-Chieng Liou, Department of Atmospheric Sciences, National Central University, Chung-Li, 320, Taiwan. tyliou@atm.ncu.edu.tw

Save