• Carr, L. E., and R. L. Elsberry, 1994: Systematic and integrated approach to tropical cyclone forecasting. Part I. Approach overview and description of meteorological basis. Naval Postgraduate School Rep. NPS-MR-94-002, 273 pp. [Available from Naval Postgraduate School, Monterey, CA 93943.].

  • Chen, S. S., and W. Frank, 1993: A numerical study of the genesis of extratropical convective mesovortices. Part I: Evolution and dynamics. J. Atmos. Sci.,50, 2401–2426.

  • Davidson, N. E., and J. McAvaney, 1981: The ANMRC Tropical Analysis System. Aust. Meteor. Mag.,29, 155–168.

  • Depperman, C. E., 1947: Notes on the origin and structures of Philippine typhoons. Bull. Amer. Meteor. Soc.,28, 399–404.

  • Dunnavan, G. M., E. J. McKinley, P. A. Harr, E. A. Ritchie, M. A. Boothe, M. Lander, and R. L. Elsberry, 1992: Tropical Cyclone Motion (TCM-92): Mini-field experiment summary. Naval Postgraduate Rep. NPS-MR-93-001, 98 pp. [Available from Naval Postgraduate School, Monterey, CA 93943.].

  • Elsberry, R. L,, G. M. Dunnavan, and E. J. McKinley, 1992: Operations plan for the Tropical Cyclone Motion (TCM-92) mini-field experiment. Naval Postgraduate School Tech. Rep. NP-MR-92-002, 45 pp. [Available from Naval Postgraduate School, Monterey, CA 93943-5000.].

  • Emanuel, K. A., 1986: An air–sea interaction theory for tropical cyclones. Part I: Steady-state maintenance. J. Atmos. Sci.,43, 585–604.

  • ——, 1991: The theory of hurricanes. Ann. Rev. Fluid. Mech.,23, 179–196.

  • Fritsch, J. M., J. D. Murphy, and J. S. Kain, 1994: Warm corevortex amplification over land. J. Atmos Sci.,51, 1780–1807.

  • Gray, W. M., 1968: Global view of the origin of tropical disturbances and storms. Mon. Wea Rev.,96, 669–700.

  • Harr, P. A., and R. L. Elsberry, 1996: Structure of a mesoscale convective system embedded in Typhoon Robyn during TCM-93. Mon. Wea Rev.,124, 634–652.

  • Holland, G. J., 1995: Scale interaction in the western Pacific monsoon. Meteor. Atmos. Phys.,56, 52–79.

  • ——, 1997: The maximum potential intensity of tropical cyclones. J. Atmos. Sci., in press.

  • ——, and G. S. Dietachmayer, 1993: On the interaction of tropical-cyclone scale vortices. Quart. J. Roy. Meteor. Soc.,119, 1381–1398.

  • ——, and M. Lander, 1993: The meandering nature of tropical cyclone tracks. J. Atmos. Sci.,50, 1254–1266.

  • Houze, R. A., Jr., 1977: Structure and dynamics of a tropical squall-line system. Mon. Wea. Rev.,105, 1540–1567.

  • Kurihara, Y., R. E. Tuleya, M. A. Bender, and R. J. Ross, 1993: Advanced modeling of tropical cyclones. Tropical Cyclone Disasters, J. Lighthill, Zeng Zhemin, G. Holland, and K. Emanuel, Eds., Peking University Press, 190–201.

  • Lander, M., and G. J. Holland, 1993: On the interaction of tropical cyclone-scale vortices. I. Observations. Quart. J. Roy Meteor. Soc.,119, 1347–1361.

  • Malkus, J. S., 1958: On the structure and maintenance of the mature hurricane eye. J. Meteor.,15, 337–349.

  • ——, and H. Riehl, 1960: On the dynamics and energy transformations in steady state hurricanes. Tellus,12, 1–20.

  • McBride, J. L., 1996: Tropical cyclone formation. Global perspectives on tropical cyclones, World Meteorological Organization Tech. Document WMO/TD-No. 693, 63–105. [Available from World Meteorological Organization, Case Postale No. 5, HC-1211, Geneva 20, Switzerland.].

  • ——, and R. Zehr, 1981: Observational analysis of tropical cyclone formation. Part II: Comparison of non-developing versus developing systems. J. Atmos. Sci.,38, 1132–1151.

  • ——, and T. D. Keenan, 1982: Climatology of tropical cyclone genesis in the Australian region. J. Climatol.,2, 13–33.

  • McRae, J. N., 1956: The formation and development of tropical cyclones during the 1955–1956 summer in Australia. Proc. Tropical Cyclone Symp., Brisbane, Australia, Bureau of Meteorology, 233–262.

  • Menard, R. O., and J. M. Fritsch, 1989: A mesoscale convective complex-generated inertially stable warm core vortex. Mon. Wea. Rev.,117, 1237–1261.

  • Miller, D., and J. M. Fritsch, 1991: Mesoscale convective complexes in the western Pacific region. Mon. Wea. Rev.,119, 2978–2992.

  • Miller, E., 1993: TOGA COARE dropsonde data report. National Center for Atmospheric Research, Boulder, CO, 75 pp. [Available from NCAR, Surface and Sounding Facility, Boulder, CO 80307-3000.].

  • Ooyama, K. V., 1982: Conceptual evolution of the theory and modeling of the tropical cyclone. J. Meteor. Soc. Japan,60, 369–380.

  • Raymond, D. J., and H. Jiang, 1990: A theory for long-lived mesoscale convective systems. J. Atmos Sci.,47,3067–3077.

  • Riehl, H., 1954: Tropical Meteorology. McGraw-Hill, 392 pp.

  • Ritchie, E. A., 1995: Mesoscale aspects of tropical cyclone formation. Ph.D. dissertation, Monash University, 167 pp. [Available from Centre for Dynamical Meteorology and Oceanography, Monash University, Melbourne, VIC 3168, Australia.].

  • ——, and G. J. Holland, 1993: On the interaction of tropical-cyclone scale vortices. II: Interacting vortex patches. Quart. J. Roy. Meteor. Soc.,119, 1363–1397.

  • ——, and ——, 1997: Scale interactions during the formation of Typhoon Irving. Mon. Wea, Rev.,125, 1377–1396.

  • Schubert, W. H., and J. J. Hack, 1982: Inertial stability and tropical cyclone development. J. Atmos. Sci.,39, 1688–1697.

  • ——, ——, P. L. Silva Dias, and S. R. Fulton, 1980: Geostrophic adjustment in an axisymmetric vortex. J. Atmos. Sci.,37, 1464–1484.

  • Stewart, S. R., and S. W. Lyons, 1996: A WSR-88D radar view of Tropical Cyclone Ed. Wea. Forecasting,11, 115–135.

  • TOGA COARE International Project Office, 1993: TOGA COARE intensive observing period observations summary. 313 pp. [Available from UCAR, Library No. 28470, Boulder, CO 80307-3000.].

  • Velden, C. S., and J. A. Young, 1994: Satellite observations during TOGA COARE: Large-scale descriptive overview. Mon. Wea. Rev.,122, 2426–2441.

  • Wang, Y., and G. J. Holland, 1995: On the interaction of tropical-cyclone-scale vortices. IV: Baroclinic vortices. Quart. J. Roy. Meteor. Soc.,121, 95–126.

  • ——, ——, and L. M. Leslie, 1993: Some baroclinic aspects of tropical cyclone motion. Tropical Cyclone Disasters, J. Lighthill, Z. Zheng, G. J. Holland, and K. Emanuel, Eds., Peking University Press, 280–285.

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Mesoscale Interactions in Tropical Cyclone Genesis

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  • 1 Earth Sciences Directorate, NASA/Goddard Space Flight Center, Greenbelt, Maryland
  • | 2 Department of Meteorology, Naval Postgraduate School, Monterey, California
  • | 3 Bureau of Meteorology Research Centre, Melbourne, Australia
  • | 4 Visiting Fellow, University Space Research Association, NASA/Goddard Space Flight Center, Greenbelt, Maryland
  • | 5 NEXRAD OSF/OTB, National Weather Service, NOAA, Norman, Oklahoma
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Abstract

With the multitude of cloud clusters over tropical oceans, it has been perplexing that so few develop into tropical cyclones. The authors postulate that a major obstacle has been the complexity of scale interactions, particularly those on the mesoscale, which have only recently been observable. While there are well-known climatological requirements, these are by no means sufficient.

A major reason for this rarity is the essentially stochastic nature of the mesoscale interactions that precede and contribute to cyclone development. Observations exist for only a few forming cases. In these, the moist convection in the preformation environment is organized into mesoscale convective systems, each of which have associated mesoscale potential vortices in the midlevels. Interactions between these systems may lead to merger, growth to the surface, and development of both the nascent eye and inner rainbands of a tropical cyclone. The process is essentially stochastic, but the degree of stochasticity can be reduced by the continued interaction of the mesoscale systems or by environmental influences. For example a monsoon trough provides a region of reduced deformation radius, which substantially improves the efficiency of mesoscale vortex interactions and the amplitude of the merged vortices. Further, a strong monsoon trough provides a vertical wind shear that enables long-lived midlevel mesoscale vortices that are able to maintain, or even redevelop, the associated convective system.

The authors develop this hypothesis by use of a detailed case study of the formation of Tropical Cyclone Oliver observed during . In this case, two dominant mesoscale vortices interacted with a monsoon trough to separately produce a nascent eye and a major rainband. The eye developed on the edge of the major convective system, and the associated atmospheric warming was provided almost entirely by moist processes in the upper atmosphere, and by a combination of latent heating and adiabatic subsidence in the lower and middle atmosphere. The importance of mesoscale interactions is illustrated further by brief reference to the development of two typhoons in the western North Pacific.

Corresponding author address: Dr. Joanne Simpson, Earth Sciences Directorate, Code 912, NASA/GSFC, Greenbelt, MD 20771.

Email: simpson@agnes.gsfc.nasa.gov

Abstract

With the multitude of cloud clusters over tropical oceans, it has been perplexing that so few develop into tropical cyclones. The authors postulate that a major obstacle has been the complexity of scale interactions, particularly those on the mesoscale, which have only recently been observable. While there are well-known climatological requirements, these are by no means sufficient.

A major reason for this rarity is the essentially stochastic nature of the mesoscale interactions that precede and contribute to cyclone development. Observations exist for only a few forming cases. In these, the moist convection in the preformation environment is organized into mesoscale convective systems, each of which have associated mesoscale potential vortices in the midlevels. Interactions between these systems may lead to merger, growth to the surface, and development of both the nascent eye and inner rainbands of a tropical cyclone. The process is essentially stochastic, but the degree of stochasticity can be reduced by the continued interaction of the mesoscale systems or by environmental influences. For example a monsoon trough provides a region of reduced deformation radius, which substantially improves the efficiency of mesoscale vortex interactions and the amplitude of the merged vortices. Further, a strong monsoon trough provides a vertical wind shear that enables long-lived midlevel mesoscale vortices that are able to maintain, or even redevelop, the associated convective system.

The authors develop this hypothesis by use of a detailed case study of the formation of Tropical Cyclone Oliver observed during . In this case, two dominant mesoscale vortices interacted with a monsoon trough to separately produce a nascent eye and a major rainband. The eye developed on the edge of the major convective system, and the associated atmospheric warming was provided almost entirely by moist processes in the upper atmosphere, and by a combination of latent heating and adiabatic subsidence in the lower and middle atmosphere. The importance of mesoscale interactions is illustrated further by brief reference to the development of two typhoons in the western North Pacific.

Corresponding author address: Dr. Joanne Simpson, Earth Sciences Directorate, Code 912, NASA/GSFC, Greenbelt, MD 20771.

Email: simpson@agnes.gsfc.nasa.gov

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