• Chang, C.-P., C.-H. Liu, and H.-C. Kuo, 2003: Typhoon Vamei: An equatorial tropical cyclone formation. Geophys. Res. Lett., 30, 1150, https://doi.org/10.1029/2002GL016365.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Chang, C.-P., P. A. Harr, and H. J. Chen, 2005: Synoptic disturbances over the equatorial South China Sea and western Maritime Continent during boreal winter. Mon. Wea. Rev., 133, 489503, https://doi.org/10.1175/MWR-2868.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Charney, J. G., and A. Eliassen, 1964: On the growth of the hurricane depression. J. Atmos. Sci., 21, 6875, https://doi.org/10.1175/1520-0469(1964)021<0068:OTGOTH>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Chen, Y.-H., H.-C. Kuo, C.-C. Wang, and Y.-T. Yang, 2017: Influence of southwest monsoon flow and typhoon track on Taiwan rainfall during the exit phase: Modeling study of Typhoon Morakot (2009). Quart. J. Roy. Meteor. Soc., 143, 30143024, https://doi.org/10.1002/qj.3156.

    • Crossref
    • 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, https://doi.org/10.1175/1520-0450(1986)025<1658:NSOTEO>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Deardorff, J. W., 1980: Stratocumulus-capped mixed layers derived from a three-dimensional model. Bound.-Layer Meteor., 18, 495527, https://doi.org/10.1007/BF00119502.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Emanuel, K. A., 1986: An air-sea interaction theory for tropical cyclones. Part I: Steady-state maintenance. J. Atmos. Sci., 43, 585605, https://doi.org/10.1175/1520-0469(1986)043<0585:AASITF>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Epifanio, C. C., 2003: Lee vortices. Encyclopedia of Atmospheric Sciences, J. R. Holton, J. Pyle, and J. A. Curry, Eds., Elsevier Science Ltd., 1150–1160.

    • Crossref
    • Export Citation
  • Epifanio, C. C., and D. R. Durran, 2001: Three-dimensional effects in high-drag-state flows over long ridges. J. Atmos. Sci., 58, 10511065, https://doi.org/10.1175/1520-0469(2001)058<1051:TDEIHD>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Farfán, L. M., and J. A. Zehnder, 1997: Orographic influence on the synoptic-scale circulations associated with the genesis of Hurricane Guillermo (1991). Mon. Wea. Rev., 125, 26832698, https://doi.org/10.1175/1520-0493(1997)125<2683:OIOTSS>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Fine, C. M., R. H. Johnson, P. E. Ciesielski, and R. K. Taft, 2016: The role of topographically induced vortices in tropical cyclone formation over the Indian Ocean. Mon. Wea. Rev., 144, 48274847, https://doi.org/10.1175/MWR-D-16-0102.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Gray, W. M., 1968: Global view of the origins of tropical disturbances and storms. Mon. Wea. Rev., 96, 669700, https://doi.org/10.1175/1520-0493(1968)096<0669:GVOTOO>2.0.CO;2.

    • Crossref
    • 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.

  • Johnson, R. H., and P. E. Ciesielski, 2013: Structure and properties of Madden–Julian Oscillations deduced from DYNAMO sounding arrays. J. Atmos. Sci., 70, 31573179, https://doi.org/10.1175/JAS-D-13-065.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Kikuchi, K., and B. Wang, 2010: Formation of tropical cyclones in the northern Indian Ocean associated with two types of tropical intraseasonal oscillation modes. J. Meteor. Soc. Japan, 88, 475496, https://doi.org/10.2151/jmsj.2010-313.

    • Crossref
    • 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, https://doi.org/10.2151/jmsj1965.54.6_382.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Kuettner, J. P., 1967: The equatorial double vortex: Unique hydrodynamic role of Sumatra in atmospheric developments over the Indian Ocean. Bull. Amer. Meteor. Soc., 48, 637.

    • Search Google Scholar
    • Export Citation
  • Kuettner, J. P., 1989: Easterly flow over the cross equatorial island of Sumatra and its role in the formation of cyclone pairs over the Indian Ocean. Wetter Leben, 41, 4755.

    • Search Google Scholar
    • Export Citation
  • Kuo, H.-C., S. Tsujino, C.-C. Huang, C.-C. Wang, and K. Tsuboki, 2019: Diagnosis of the dynamic efficiency of latent heat release and the rapid intensification of Supertyphoon Haiyan (2013). Mon. Wea. Rev., 147, 11271147, https://doi.org/10.1175/MWR-D-18-0149.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Lee, C.-S., 1986: An observational study of tropical cloud cluster evolution and cyclogenesis in the western North Pacific. Department of Atmospheric Science Paper 403, Colorado State University, 250 pp.

  • Lee, C.-S., R. Edson, and W. M. Gray, 1989: Some large-scale characteristics associated with tropical cyclone development in the North Indian Ocean during FGGE. Mon. Wea. Rev., 117, 407426, https://doi.org/10.1175/1520-0493(1989)117<0407:SLSCAW>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Lin, Y.-L., and C.-S. Lee, 2011: An analysis of tropical cyclone formations in the South China Sea during the late season. Mon. Wea. Rev., 139, 27482760, https://doi.org/10.1175/2011MWR3495.1.

    • Crossref
    • 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, https://doi.org/10.1175/1520-0450(1983)022<1065:BPOTSF>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Louis, J. F., M. Tiedtke, and J. F. Geleyn, 1982: A short history of the operational PBL parameterization at ECMWF. Workshop on Planetary Boundary Layer Parameterization, Reading, United Kingdom, ECMWF, 59–79.

  • Love, G., 1985a: Cross-equatorial influence of winter hemisphere subtropical cold surges. Mon. Wea. Rev., 113, 14871498, https://doi.org/10.1175/1520-0493(1985)113<1487:CEIOWH>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Love, G., 1985b: Cross-equatorial interaction during tropical cyclone genesis. Mon. Wea. Rev., 113, 14991509, https://doi.org/10.1175/1520-0493(1985)113<1499:CEIDTC>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Moncrieff, M. W., D. E. Waliser, M. J. Miller, M. A. Shapiro, G. R. Asrar, and J. Caughey, 2012: Multiscale convective organization and the YOTC virtual global field campaign. Bull. Amer. Meteor. Soc., 93, 11711187, https://doi.org/10.1175/BAMS-D-11-00233.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Mozer, J. B., and J. A. Zehnder, 1996: Lee vorticity production by large-scale tropical mountain ranges. Part I: Eastern North Pacific tropical cyclogenesis. J. Atmos. Sci., 53, 521538, https://doi.org/10.1175/1520-0469(1996)053<0521:LVPBLS>2.0.CO;2.

    • Crossref
    • 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, https://doi.org/10.2151/jmsj1965.68.2_107.

    • Crossref
    • 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, https://doi.org/10.2151/jmsj1965.72.1_43.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Ooyama, K. V., 1982: Conceptual evolution of the theory and modeling of the tropical cyclone. J. Meteor. Soc. Japan, 60, 369380, https://doi.org/10.2151/jmsj1965.60.1_369.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Ritchie, E. A., and G. J. Holland, 1999: Large-scale patterns associated with tropical cyclogenesis in the western Pacific. Mon. Wea. Rev., 127, 20272043, https://doi.org/10.1175/1520-0493(1999)127<2027:LSPAWT>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Rotunno, R., and K. A. Emanuel, 1987: An air-sea interaction theory for tropical cyclones. Part II: Evolutionary study using a nonhydrostatic axisymmetric numerical model. J. Atmos. Sci., 44, 542561, https://doi.org/10.1175/1520-0469(1987)044<0542:AAITFT>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Rotunno, R., and P. K. Smolarkiewicz, 1991: Further results on lee vortices in low-Froude-number flow. J. Atmos. Sci., 48, 22042211, https://doi.org/10.1175/1520-0469(1991)048<2204:FROLVI>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Rydbeck, A. V., E. C. Maloney, and G. J. Alaka Jr., 2017: In situ initiation of East Pacific easterly waves in a regional model. J. Atmos. Sci., 74, 333351, https://doi.org/10.1175/JAS-D-16-0124.1.

    • Crossref
    • 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, https://doi.org/10.2151/JMSJ1965.67.5_907.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Smolarkiewicz, P. K., and R. Rotunno, 1989: Low Froude number flow past three-dimensional obstacles. Part I: Baroclinically generated lee vortices. J. Atmos. Sci., 46, 11541164, https://doi.org/10.1175/1520-0469(1989)046<1154:LFNFPT>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Subbaramayya, I., and S. R. M. Rao, 1984: Frequency of Bay of Bengal cyclones in the post-monsoon season. Mon. Wea. Rev., 112, 16401642, https://doi.org/10.1175/1520-0493(1984)112<1640:FOBOBC>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Takahashi, H. G., Y. Fukutomi, and J. Matsumoto, 2011: The impact of long-lasting northerly surges of the East Asian winter monsoon on tropical cyclogenesis and its seasonal march. J. Meteor. Soc. Japan, 89A, 181200, https://doi.org/10.2151/jmsj.2011-A12.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Tsuboki, K., and A. Sakakibara, 2002: Large-scale parallel computing of cloud resolving storm simulator. High Performance Computing, H. P. Zima et al., Eds., Springer, 243–259.

    • Crossref
    • Export Citation
  • Tsuboki, K., and A. Sakakibara, 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 et al. , 2012: The “year” of tropical convection (May 2008–April 2010): Climate variability and weather highlights. Bull. Amer. Meteor. Soc., 93, 11891218, https://doi.org/10.1175/2011BAMS3095.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Wang, C.-C., 2015: The more rain, the better the model performs—The dependency of quantitative precipitation forecast skill on rainfall amount for typhoons in Taiwan. Mon. Wea. Rev., 143, 17231748, https://doi.org/10.1175/MWR-D-14-00137.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Wang, C.-C., H.-C. Kuo, Y.-H. Chen, H.-L. Huang, C.-H. Chung, and K. Tsuboki, 2012: Effects of asymmetric latent heating on typhoon movement crossing Taiwan: The case of Morakot (2009) with extreme rainfall. J. Atmos. Sci., 69, 31723196, https://doi.org/10.1175/JAS-D-11-0346.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Wang, C.-C., Y.-H. Chen, H.-C. Kuo, and S.-Y. Huang, 2013: Sensitivity of typhoon track to asymmetric latent heating/rainfall induced by Taiwan topography: A numerical study of Typhoon Fanapi (2010). J. Geophys. Res. Atmos., 118, 32923308, https://doi.org/10.1002/JGRD.50351.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Wang, C.-C., H.-C. Kuo, R. H. Johnson, C.-Y. Lee, S.-Y. Huang, and Y.-H. Chen, 2015: A numerical study of convection in rainbands of Typhoon Morakot (2009) with extreme rainfall: Roles of pressure perturbations with low-level wind maxima. Atmos. Chem. Phys., 15, 11 09711 115, https://doi.org/10.5194/acp-15-11097-2015.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Wang, C.-C., S.-Y. Huang, S.-H. Chen, C.-S. Chang, and K. Tsuboki, 2016: Cloud-resolving typhoon rainfall ensemble forecasts for Taiwan with large domain and extended range through time-lagged approach. Wea. Forecasting, 31, 151172, https://doi.org/10.1175/WAF-D-15-0045.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Zehnder, J. A., D. M. Powell, and D. L. Ropp, 1999: The interaction of easterly waves, orography, and the intertropical convergence zone in the genesis of eastern Pacific tropical cyclones. Mon. Wea. Rev., 127, 15661585, https://doi.org/10.1175/1520-0493(1999)127<1566:TIOEWO>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
All Time Past Year Past 30 Days
Abstract Views 95 95 20
Full Text Views 25 25 5
PDF Downloads 28 28 3

A Numerical Study on the Influences of Sumatra Topography and Synoptic Features on Tropical Cyclone Formation over the Indian Ocean

View More View Less
  • 1 Department of Earth Sciences, National Taiwan Normal University, Taipei, Taiwan
  • | 2 Department of Atmospheric Sciences, Colorado State University, Fort Collins, Colorado
© Get Permissions
Restricted access

Abstract

Spanning across the equator with a northwest–southeast orientation, the island of Sumatra can exert significant influences on low-level flow. Under northeasterly flow, in particular, lee vortices can form and some of them may subsequently develop into tropical cyclones (TCs) in the Indian Ocean (IO). Building upon the recent work of Fine et al., this study investigates the roles of the Sumatra topography and other common features on the formation of selected cases for analysis and numerical experiments. Four cases in northern IO were selected for analysis and two of them [Nisha (2008) and Ward 2009)] for simulation at a grid size of 4 km. Sensitivity tests without the Sumatra topography were also performed. Our results indicate that during the lee stage, most pre-TC vortices tend to be stronger with a clearer circulation when the topography is present. However, the island’s terrain is a helpful but not a deciding factor in TC formation. Specifically, the vortices in the no-terrain tests also reach TC status, but just at a later time. Some common ingredients contributing to a favorable environment for TC genesis are identified. They include northeasterly winds near northern Sumatra, westerly wind bursts along the equator, and migratory disturbances (TC remnants or Borneo vortices) to provide additional vorticity/moisture from the South China Sea. These factors also appear in most of the 22 vortices in northern IO during October–December in 2008 and 2009. For the sole case (Cleo) examined in southern IO, the deflection of equatorial westerlies into northwesterlies by Sumatra (on the windward side) is also helpful to TC formation.

Corresponding author: Prof. Chung-Chieh Wang, cwang@ntnu.edu.tw

Abstract

Spanning across the equator with a northwest–southeast orientation, the island of Sumatra can exert significant influences on low-level flow. Under northeasterly flow, in particular, lee vortices can form and some of them may subsequently develop into tropical cyclones (TCs) in the Indian Ocean (IO). Building upon the recent work of Fine et al., this study investigates the roles of the Sumatra topography and other common features on the formation of selected cases for analysis and numerical experiments. Four cases in northern IO were selected for analysis and two of them [Nisha (2008) and Ward 2009)] for simulation at a grid size of 4 km. Sensitivity tests without the Sumatra topography were also performed. Our results indicate that during the lee stage, most pre-TC vortices tend to be stronger with a clearer circulation when the topography is present. However, the island’s terrain is a helpful but not a deciding factor in TC formation. Specifically, the vortices in the no-terrain tests also reach TC status, but just at a later time. Some common ingredients contributing to a favorable environment for TC genesis are identified. They include northeasterly winds near northern Sumatra, westerly wind bursts along the equator, and migratory disturbances (TC remnants or Borneo vortices) to provide additional vorticity/moisture from the South China Sea. These factors also appear in most of the 22 vortices in northern IO during October–December in 2008 and 2009. For the sole case (Cleo) examined in southern IO, the deflection of equatorial westerlies into northwesterlies by Sumatra (on the windward side) is also helpful to TC formation.

Corresponding author: Prof. Chung-Chieh Wang, cwang@ntnu.edu.tw
Save