• Akter, N., and K. Tsuboki, 2012: Numerical simulation of Cyclone Sidr using a cloud-resolving model: Characteristics and formation process of an outer rainband. Mon. Wea. Rev., 140, 789810.

    • Search Google Scholar
    • Export Citation
  • Asselin, R., 1972: Frequency filter for time integrations. Mon. Wea. Rev., 100, 487490.

  • Chan, J. C.-L., 1984: An observational study of the physical processes responsible for tropical cyclone motion. J. Atmos. Sci., 41, 10361048.

    • Search Google Scholar
    • Export Citation
  • Chan, J. C.-L., F. M. F. Ko, and Y. M. Lei, 2002: Relationship between potential vorticity tendency and tropical cyclone motion. J. Atmos. Sci., 59, 13171336.

    • Search Google Scholar
    • Export Citation
  • Chang, C.-P., T.-C. Yeh, and J.-M. Chen, 1993: Effects of terrain on the surface structure of typhoons over Taiwan. Mon. Wea. Rev., 121, 734752.

    • Search Google Scholar
    • Export Citation
  • Chanson, H., 2010: The impact of Typhoon Morakot on the southern Taiwan coast. Shore Beach, 78 (2), 3337.

  • Chen, T.-C., and Coauthors, 2010: The characteristics of radar-observed mesoscale rainbands of Typhoon Morakot (in Chinese). Scientific report on Typhoon Morakot (2009), H.-H. Hsu et al., Eds., National Science Council, 53–81.

  • Chien, F.-C., and H.-C. Kuo, 2011: On the extreme rainfall of Typhoon Morakot (2009). J. Geophys. Res., 116, D05104, doi:10.1029/2010JD015092.

    • Search Google Scholar
    • Export Citation
  • Corbosiero, K. L., and J. Molinari, 2002: The effects of vertical wind shear on the distribution of convection in tropical cyclones. Mon. Wea. Rev., 130, 21102123.

    • Search Google Scholar
    • Export Citation
  • Corbosiero, K. L., and J. Molinari, 2003: The relationship between storm motion, vertical wind shear, and convective asymmetries in tropical cyclones. J. Atmos. Sci., 60, 366376.

    • Search Google Scholar
    • Export Citation
  • Cotton, W. R., G. J. Tripoli, R. M. Rauber, and E. A. Mulvihill, 1986: Numerical simulation of the effects of varying ice crystal nucleation rates and aggregation processes on orographic snowfall. J. Climate Appl. Meteor., 25, 16581680.

    • Search Google Scholar
    • Export Citation
  • Fang, X., Y.-H. Kuo, and A. Wang, 2011: The impact of Taiwan topography on the predictability of Typhoon Morakot’s record-breaking rainfall: A high-resolution ensemble simulation. Wea. Forecasting, 26, 613633.

    • Search Google Scholar
    • Export Citation
  • Fiorino, M., and R. L. Elsberry, 1989: Some aspects of vortex structure related to tropical cyclone motion. J. Atmos. Sci., 46, 975990.

    • Search Google Scholar
    • Export Citation
  • Gall, R., 1976: The effects of released latent heat in growing baroclinic waves. J. Atmos. Sci., 33, 16861701.

  • Ge, X., T. Li, S. Zhang, and M. S. Peng, 2010: What causes the extremely heavy rainfall in Taiwan during Typhoon Morakot (2009)? Atmos. Sci. Lett., 11, 4650.

    • Search Google Scholar
    • Export Citation
  • Hendricks, E. A., J. R. Moskaitis, Y. Jin, R. M. Hodur, J. D. Doyle, and M. S. Peng, 2011: Prediction and diagnosis of Typhoon Morakot (2009) using the Naval Research Laboratory’s mesoscale tropical cyclone model. Terr. Atmos. Oceanic Sci., 22, 579594, doi:10.3319/TAO.2011.05.30.01(TM).

    • Search Google Scholar
    • Export Citation
  • Hong, C.-C., M.-Y. Lee, H.-H. Hsu, and J.-L. Kuo, 2010: Role of submonthly disturbance and 40–50 day ISO on the extreme rainfall event associated with Typhoon Morakot (2009) in southern Taiwan. Geophys. Res. Lett., 37, L08805, doi:10.1029/2010GL042761.

    • Search Google Scholar
    • Export Citation
  • Hsu, H.-H., and Coauthors, Eds., 2010: Scientific report on Typhoon Morakot (2009) (in Chinese). National Science Council, 192 pp.

  • Hsu, J., 1998: ARMTS up and running in Taiwan. Väisälä News, 146, 2426.

  • Huang, C.-Y., C.-S. Wong, and T.-C. Yeh, 2011: Extreme rainfall mechanisms exhibited by Typhoon Morakot (2009). Terr. Atmos. Oceanic Sci., 22, 613632, doi:10.3319/TAO.2011.07.01.01(TM).

    • Search Google Scholar
    • Export Citation
  • Ikawa, M., and K. Saito, 1991: Description of a nonhydrostatic model developed at the Forecast Research Department of the MRI. MRI Tech. Rep. 28, 238 pp.

  • Jou, B. J.-D., C.-S. Lee, M.-D. Cheng, L. Feng, and Y.-C. Yu, 2010: Analysis on the synoptic environment and rainfall characteristics of Typhoon Morakot (in Chinese). Scientific report on Typhoon Morakot (2009), H.-H. Hsu et al., Eds., National Science Council, 1–26.

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

    • Search Google Scholar
    • Export Citation
  • Kondo, J., 1976: Heat balance of the China Sea during the air mass transformation experiment. J. Meteor. Soc. Japan, 54, 382398.

  • Kuo, H.-C., Y.-T. Yang, and C.-P. Chang, 2010: Typhoon Morakot (2009): Interplay of southwest monsoon, terrain, and mesoscale convection. Int. Workshop on Typhoon Morakot (2009), Taipei, Taiwan, National Science Council and National Applied Research Laboratories, 55–73.

  • Kuo, Y.-H., R. Reed, and Y. Liu, 1996: The ERICA IOP 5 storm. Part III: Mesoscale cyclogenesis and precipitation parameterization. Mon. Wea. Rev., 124, 14091434.

    • Search Google Scholar
    • Export Citation
  • Liang, J., L. Wu, X. Ge, and C.-C. Wu, 2011: Monsoonal influence on Typhoon Morakot (2009). Part II: Numerical study. J. Atmos. Sci., 68, 22222235.

    • Search Google Scholar
    • Export Citation
  • Lin, Y.-L., R. D. Farley, and H. D. Orville, 1983: Bulk parameterization of the snow field in a cloud model. J. Climate Appl. Meteor., 22, 10651092.

    • Search Google Scholar
    • Export Citation
  • Louis, J. F., M. Tiedtke, and J. F. Geleyn, 1981: A short history of the operational PBL parameterization at ECMWF. Workshop on Planetary Boundary Layer Parameterization, Reading, United Kingdom, ECMWF, 59–79.

  • Mellor, G. L., and T. Yamada, 1974: A hierarchy of turbulent closure models for planetary boundary layers. J. Atmos. Sci., 31, 17911806.

    • Search Google Scholar
    • Export Citation
  • Miller, C. A., and A. G. Davenport, 1998: Guidelines for the calculation of wind speed-ups in complex terrain. J. Wind Eng. Ind. Aerodyn., 74–76, 189197.

    • Search Google Scholar
    • Export Citation
  • Moncrieff, M. W., 2010: The multiscale organization of moist convection and the intersection of weather and climate. Why Does Climate Vary?, Geophys. Monogr., Vol. 189, Amer. Geophys. Union, 3–26.

  • Mullen, S. L., and D. P. Baumhefner, 1988: Sensitivity of numerical simulations of explosive oceanic cyclogenesis to changes in physical parameterization. Mon. Wea. Rev., 116, 22892329.

    • Search Google Scholar
    • Export Citation
  • Murakami, M., 1990: Numerical modeling of dynamical and microphysical evolution of an isolated convective cloud—The 19 July 1981 CCOPE cloud. J. Meteor. Soc. Japan, 68, 107128.

    • Search Google Scholar
    • Export Citation
  • Murakami, M., T. L. Clark, and W. D. Hall, 1994: Numerical simulations of convective snow clouds over the Sea of Japan: Two-dimensional simulation of mixed layer development and convective snow cloud formation. J. Meteor. Soc. Japan, 72, 4362.

    • Search Google Scholar
    • Export Citation
  • Nguyen, H. V., and Y.-L. Chen, 2011: High-resolution initialization and simulations of Typhoon Morakot (2009). Mon. Wea. Rev., 139, 14631491.

    • Search Google Scholar
    • Export Citation
  • Reynolds, R. W., N. A. Rayner, T. M. Smith, D. C. Stokes, and W. Wang, 2002: An improved in situ and satellite SST analysis for climate. J. Climate, 15, 16091625.

    • Search Google Scholar
    • Export Citation
  • Segami, A., K. Kurihara, H. Nakamura, M. Ueno, I. Takano, and Y. Tatsumi, 1989: Operational mesoscale weather prediction with Japan Spectral Model. J. Meteor. Soc. Japan, 67, 907924.

    • Search Google Scholar
    • Export Citation
  • Tsuboki, K., and A. Sakakibara, 2002: Large-scale parallel computing of cloud resolving storm simulator. High Performance Computing: 4th International Symposium, H. P. Zima et al., Eds., Lecture Notes in Computer Science, Vol. 2327, Springer, 243–259.

  • Tsuboki, K., and A. Sakakibara, Eds., 2007: Numerical Prediction of High-Impact Weather Systems: The Textbook for the Seventeenth IHP Training Course in 2007. Hydrospheric Atmospheric Research Center, Nagoya University, and UNESCO, 273 pp.

  • Waliser, D. E., and M. Moncrieff, 2007: Year of tropical convection—A Joint WCRP-THORPEX activity to address the challenge of tropical convection. GEWEX News, No. 2, International GEWEX Project Office, Silver Spring, MD, 8–9.

  • Wang, C.-C., and W.-M. Huang, 2009: High-resolution simulation of a nocturnal narrow convective line off the southeastern coast of Taiwan in the mei-yu season. Geophys. Res. Lett., 36, L06815, doi:10.1029/2008GL037147.

    • Search Google Scholar
    • Export Citation
  • Wang, C.-C., G. T.-J. Chen, and S.-Y. Huang, 2011: Remote trigger of deep convection by cold outflow over the Taiwan Strait in the mei-yu season: A modeling study of the 8 June 2007 case. Mon. Wea. Rev., 139, 28542875.

    • Search Google Scholar
    • Export Citation
  • Wang, Y., and G. J. Holland, 1996: Tropical cyclone motion and evolution in vertical shear. J. Atmos. Sci., 53, 33133332.

  • Willoughby, H. E., 1992: Linear motion of a shallow-water barotropic vortex as an initial-value problem. J. Atmos. Sci., 47, 242264.

  • Wu, C.-C., and Y.-H. Kuo, 1999: Typhoons affecting Taiwan: Current understanding and future challenges. Bull. Amer. Meteor. Soc., 80, 6780.

    • Search Google Scholar
    • Export Citation
  • Wu, C.-C., T.-H. Yen, Y.-H. Kuo, and W. Wang, 2002: Rainfall simulation associated with Typhoon Herb (1996) near Taiwan. Part I: The topographic effect. Wea. Forecasting, 17, 10011015.

    • Search Google Scholar
    • Export Citation
  • Wu, L., and B. Wang, 2001: Effects of convective heating on movement and vertical coupling of tropical cyclones: A numerical study. J. Atmos. Sci., 58, 36393649.

    • Search Google Scholar
    • Export Citation
  • Wu, L., J. Liang, and C.-C. Wu, 2011: Monsoonal influence on Typhoon Morakot (2009). Part I: Observational analysis. J. Atmos. Sci., 68, 22082221.

    • Search Google Scholar
    • Export Citation
  • Yen, T.-H., C.-C. Wu, and G.-Y. Lien, 2011: Rainfall simulations of Typhoon Morakot with controlled translation speed based on EnKF data assimilation. Terr. Atmos. Oceanic Sci., 22, 647660, doi:10.3319/TAO.2011.07.05.01(TM).

    • Search Google Scholar
    • Export Citation
All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 420 190 7
PDF Downloads 278 124 2

Effects of Asymmetric Latent Heating on Typhoon Movement Crossing Taiwan: The Case of Morakot (2009) with Extreme Rainfall

View More View Less
  • 1 * Department of Earth Sciences, National Taiwan Normal University, Taipei, Taiwan
  • | 2 Department of Atmospheric Sciences, National Taiwan University, Taipei, Taiwan
  • | 3 Hydrospheric Atmospheric Research Center, Nagoya University, Nagoya, Japan
Restricted access

Abstract

Typhoon Morakot struck Taiwan during 6–9 August 2009, and it produced the highest rainfall (approaching 3000 mm) and caused the worst damage in the past 50 yr. Typhoon–monsoon flow interactions with mesoscale convection, the water vapor supply by the monsoon flow, and the slow moving speed of the storm are the main reasons for the record-breaking precipitation. Analysis of the typhoon track reveals that the steering flow, although indeed slow, still exceeded the typhoon moving speed by approximately 5 km h−1 (1 km h−1 = 0.28 m s−1) during the postlandfall period on 8 August, when the rainfall was the heaviest. The Cloud-Resolving Storm Simulator (CReSS) is used to study the dynamics of the slow storm motion toward the north-northwest upon leaving Taiwan. The control simulations with 3-km grid size compare favorably with the observations, including the track, slow speed, asymmetric precipitation pattern, mesoscale convection, and rainfall distribution over Taiwan. Sensitivity tests with reduced moisture content reveal that not only did the model rainfall decrease but also the typhoon translation speed increased. Specifically, the simulations consistently show a discernible impact on storm motion by as much as 50%, as the storms with full moisture move slower (~5 km h−1), while those with limited moisture (≤25%) move faster (~10 km h−1). Thus, in addition to a weak steering flow, the prolonged asymmetric precipitation in Typhoon Morakot also contributed to its very slow motion upon leaving Taiwan, and both lengthened the heavy-rainfall period and increased the total rainfall amount. The implications of a realistic representation of cloud microphysics from the standpoint of tropical cyclone track forecasts are also briefly discussed.

Corresponding author address: Prof. Chung-Chieh Wang, Department of Earth Sciences, National Taiwan Normal University, No. 88, Sec. 4, Tingzhou Rd., Taipei 11677, Taiwan. E-mail: cwang@ntnu.edu.tw

Abstract

Typhoon Morakot struck Taiwan during 6–9 August 2009, and it produced the highest rainfall (approaching 3000 mm) and caused the worst damage in the past 50 yr. Typhoon–monsoon flow interactions with mesoscale convection, the water vapor supply by the monsoon flow, and the slow moving speed of the storm are the main reasons for the record-breaking precipitation. Analysis of the typhoon track reveals that the steering flow, although indeed slow, still exceeded the typhoon moving speed by approximately 5 km h−1 (1 km h−1 = 0.28 m s−1) during the postlandfall period on 8 August, when the rainfall was the heaviest. The Cloud-Resolving Storm Simulator (CReSS) is used to study the dynamics of the slow storm motion toward the north-northwest upon leaving Taiwan. The control simulations with 3-km grid size compare favorably with the observations, including the track, slow speed, asymmetric precipitation pattern, mesoscale convection, and rainfall distribution over Taiwan. Sensitivity tests with reduced moisture content reveal that not only did the model rainfall decrease but also the typhoon translation speed increased. Specifically, the simulations consistently show a discernible impact on storm motion by as much as 50%, as the storms with full moisture move slower (~5 km h−1), while those with limited moisture (≤25%) move faster (~10 km h−1). Thus, in addition to a weak steering flow, the prolonged asymmetric precipitation in Typhoon Morakot also contributed to its very slow motion upon leaving Taiwan, and both lengthened the heavy-rainfall period and increased the total rainfall amount. The implications of a realistic representation of cloud microphysics from the standpoint of tropical cyclone track forecasts are also briefly discussed.

Corresponding author address: Prof. Chung-Chieh Wang, Department of Earth Sciences, National Taiwan Normal University, No. 88, Sec. 4, Tingzhou Rd., Taipei 11677, Taiwan. E-mail: cwang@ntnu.edu.tw
Save