• Andrews, D. G., 1983: A finite amplitude Eliassen–Palm theorem in isentropic coordinates. J. Atmos. Sci.,40, 1877–1883.

  • Appenzeller, C., H. C. Davies, and W. A. Norton, 1996: Fragmentation of stratospheric intrusions. J. Geophys. Res.,101, 1435–1456.

  • Colton, D. E., 1973: Barotropic scale interactions in the tropical upper troposphere during the northern summer. J. Atmos. Sci.,30, 1287–1302.

  • Dritschel, D. G., 1989: On the stabilization of a two-dimensional vortex strip by adverse shear. J. Fluid Mech.,206, 193–221.

  • Gallimore, R. G., and D. R. Johnson, 1981: The forcing of the meridional circulation of the isentropic zonally averaged circumpolar vortex. J. Atmos. Sci.,38, 583–599.

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

  • ——, 1979: Hurricanes: Their formation, structure and likely role in the tropical circulation. Meteorology over the Tropical Oceans, D. B. Shaw, Ed., Royal Meteorological Society, 155–218.

  • Habjan, E. E., and G. J. Holland, 1995: Extratropical transitions of tropical cyclones in the western Australia region. Proc. 21st Conf. on Hurricanes and Tropical Meteorology, Miami, FL, Amer. Meteor. Soc., 310–311.

  • Hack, J. J., and R. Jakob, 1992: Description of a global shallow water model based on the transform method. NCAR Tech. Note NCAR/TN-343+STR, 39 pp. [Available from Climate and Global Dynamics Divisions, NCAR, P.O. Box 3000, Boulder, CO 80307.].

  • Held, I., and P. J. Phillips, 1987: Linear and nonlinear barotropic decay on the sphere. J. Atmos. Sci.,44, 200–207.

  • ——, and ——, 1990: A barotropic model of the interaction between the Hadley cell and a Rossby wave. J. Atmos. Sci.,47, 856–869.

  • Hodanish, S., and W. M. Gray, 1993: An observational analysis of tropical cyclone recurvature. Mon. Wea. Rev.,121, 2665–2689.

  • Holton, J. R., P. H. Haynes, M. E. McIntyre, A. R. Douglass, R. B. Rood, and L. Pfister, 1995: Stratosphere-troposphere exchange. Rev. Geophys.,33, 403–439.

  • Hoskins, B. J., and M. J. Rodwell, 1995: A model of the Asian summer monsoon. Part I: The global scale. J. Atmos. Sci.,52, 1329–1340.

  • ——, A. J. Simmons, and D. G. Andrews, 1977: Energy dispersion in a barotropic atmosphere. Quart. J. Roy. Meteor. Soc.,103, 553–567.

  • ——, M. E. McIntyre, and A. W. Robertson, 1985: On the use and significance of isentropic potential vorticity maps. Quart. J. Roy. Meteor. Soc.,111, 877–946.

  • Jakob-Chien, R. J., J. J. Hack, and D. L. Williamson, 1995: Spectral transform solutions to the shallow water test set. J. Comput. Phys.,119, 164–187.

  • Joly, A., and A. J. Thorpe, 1990: Frontal instability generated by tropospheric potential vorticity anomalies. Quart. J. Roy. Meteor. Soc.,116, 525–560.

  • Juckes, M. N., and M. E. McIntyre, 1987: A high-resolution one-layer model of breaking planetary waves in the stratosphere. Nature,328, 590–596.

  • Kelley, W. E., Jr., and D. R. Mock, 1982: A diagnostic study of upper tropospheric cold lows over the western North Pacific. Mon. Wea. Rev.,110, 471–480.

  • Laprise, R., 1992: The resolution of global spectral models. Bull. Amer. Meteor. Soc.,73, 1453–1454.

  • McIntyre, M. E., and T. N. Palmer, 1984: The “surf zone” in the stratosphere. J. Atmos. Terr. Phys.,46, 825–849.

  • Melander, M. V., J. C. McWilliams, and N. J. Zabusky, 1987: Axisymmetrization and vorticity-gradient intensification of an isolated two-dimensional vortex through filamentation. J. Fluid Mech.,178, 137–159.

  • Molinari, J., S. Skubis, and D. Vollaro, 1995: External influences on hurricane intensity. Part III: Potential vorticity structure. J. Atmos. Sci.,52, 3593–3606.

  • Montgomery, M. T., and B. F. Farrell, 1993: Tropical cyclone formation. J. Atmos. Sci.,50, 285–310.

  • Nakamura, M., and R. A. Plumb, 1994: The effects of flow asymmetry on the direction of Rossby wave breaking. J. Atmos. Sci.,51, 2031–2045.

  • Nieto Ferreira, R., and W. H. Schubert, 1997: Barotropic aspects of ITCZ breakdown. J. Atmos. Sci.,54, 261–285.

  • Peixoto, J. P., and A. H. Oort, 1992: Physics of Climate. American Institute of Physics, 520 pp.

  • Pfeffer, R. L., 1981: Wave-mean flow interactions in the atmosphere. J. Atmos. Sci.,38, 1340–1359.

  • ——, and M. Challa, 1992: The role of environmental asymmetries in Atlantic hurricane formation. J. Atmos. Sci.,49, 1051–1059.

  • Polvani, L. M., and R. A. Plumb, 1992: Rossby wave breaking, microbreaking, filamentation, and secondary vortex formation: The dynamics of a perturbed vortex. J. Atmos. Sci.,49, 462–476.

  • Price, J. D., and G. Vaughan, 1992: Statistical studies of cut-off-low systems. Ann. Geophys.,10, 96–102.

  • ——, and ——, 1993: The potential for stratosphere-troposphere exchange in cut-off-low systems. Quart. J. Roy. Meteor. Soc.,119, 343–365.

  • Sadler, J., 1975: The upper tropospheric circulation over the global tropics. UHMET 75-02, 103 pp. [Available from the Department of Meteorology, University of Hawaii at Manoa, 2525 Correa Rd., Honolulu, HI 96822.].

  • Shapiro, L. J., and K. V. Ooyama, 1990: Barotropic vortex evolution on a beta plane. J. Atmos. Sci.,47, 170–187.

  • Silva Dias, P. L., W. H. Schubert, and M. DeMaria, 1983: Large-scale response of the tropical atmosphere to transient convection. J. Atmos. Sci.,40, 2689–2707.

  • Thorncroft, C. D., B. J. Hoskins, and M. E. McIntyre, 1993: Two paradigms of baroclinic-wave life-cycle behaviour. Quart. J. Roy. Meteor. Soc.,119, 17–55.

  • Thorpe, A. J., 1985: Diagnosis of balanced vortex structure using potential vorticity. J. Atmos. Sci.,42, 397–406.

  • Tung, K. K., 1986: Nongeostrophic theory of zonally averaged circulation. Part I: Formulation. J. Atmos. Sci.,43, 2600–2618.

  • Webster, P. J., 1972: Response of the tropical atmosphere to local steady forcing. Mon. Wea. Rev.,100, 518–541.

  • Whitfield, M. B., and S. W. Lyons, 1992: An upper-level low over Texas during summer. Wea. Forecasting,7, 89–106.

All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 351 110 20
PDF Downloads 223 87 5

The Role of Tropical Cyclones in the Formation of Tropical Upper-Tropospheric Troughs

Rosana Nieto FerreiraUniversities Space Research Association, NASA/GSFC Laboratory for Atmospheres, Greenbelt, Maryland

Search for other papers by Rosana Nieto Ferreira in
Current site
Google Scholar
PubMed
Close
and
Wayne H. SchubertDepartment of Atmospheric Science, Colorado State University, Fort Collins, Colorado

Search for other papers by Wayne H. Schubert in
Current site
Google Scholar
PubMed
Close
Restricted access

Abstract

Tropical upper-tropospheric troughs (TUTTs), also known as midoceanic troughs, are elongated troughs that appear in summer monthly averaged maps of the upper-tropospheric flow over the oceans. The transient part of these climatological features is composed of TUTT cells and their origin is the subject of this study.

TUTT cells often occur to the east of tropical cyclones. A nonlinear shallow water model on the sphere was used in a simplified study of the interactions between tropical cyclones and the circumpolar vortex. Based on the results of these simulations and keeping in mind their limitations, it is proposed that dispersion of short Rossby wave energy is a possible mechanism to explain the formation of TUTT cells to the east of tropical cyclones. The model simulations suggest that two types of TUTT cells may form to the east of tropical cyclones. When embedded in cyclonic or weak anticyclonic shear, the trough to the east of the tropical cyclone may broaden, resulting in the formation of an intense TUTT cell that has a strong signature in the wind and mass fields. In the presence of stronger anticyclonic shear, the trough to the east of the tropical cyclone may become a thin and elongated TUTT cell that has a comparatively negligible signature in the mass and flow fields. Moreover, the model simulations indicate that the mode of evolution of TUTT cells that form to the east of a tropical cyclone is strongly dependent on the intensity and relative location of midlatitude waves.

Wave–mean flow interaction calculations indicated that tropical cyclones produced a westerly acceleration of the mean zonal flow in the latitudinal band through which they move and an easterly acceleration elsewhere. These calculations also indicated that broadening TUTT cells may cause an easterly acceleration of the zonal mean flow.

Corresponding author address: Dr. Rosana Nieto Ferreira, NASA/GSFC, Mailcode 913.0, Greenbelt, MD 20771.

Email: ferreira@janus.gsfc.nasa.gov

Abstract

Tropical upper-tropospheric troughs (TUTTs), also known as midoceanic troughs, are elongated troughs that appear in summer monthly averaged maps of the upper-tropospheric flow over the oceans. The transient part of these climatological features is composed of TUTT cells and their origin is the subject of this study.

TUTT cells often occur to the east of tropical cyclones. A nonlinear shallow water model on the sphere was used in a simplified study of the interactions between tropical cyclones and the circumpolar vortex. Based on the results of these simulations and keeping in mind their limitations, it is proposed that dispersion of short Rossby wave energy is a possible mechanism to explain the formation of TUTT cells to the east of tropical cyclones. The model simulations suggest that two types of TUTT cells may form to the east of tropical cyclones. When embedded in cyclonic or weak anticyclonic shear, the trough to the east of the tropical cyclone may broaden, resulting in the formation of an intense TUTT cell that has a strong signature in the wind and mass fields. In the presence of stronger anticyclonic shear, the trough to the east of the tropical cyclone may become a thin and elongated TUTT cell that has a comparatively negligible signature in the mass and flow fields. Moreover, the model simulations indicate that the mode of evolution of TUTT cells that form to the east of a tropical cyclone is strongly dependent on the intensity and relative location of midlatitude waves.

Wave–mean flow interaction calculations indicated that tropical cyclones produced a westerly acceleration of the mean zonal flow in the latitudinal band through which they move and an easterly acceleration elsewhere. These calculations also indicated that broadening TUTT cells may cause an easterly acceleration of the zonal mean flow.

Corresponding author address: Dr. Rosana Nieto Ferreira, NASA/GSFC, Mailcode 913.0, Greenbelt, MD 20771.

Email: ferreira@janus.gsfc.nasa.gov

Save