Skip to main content
Log in

An observational study of 300 mb winds in the tropical belt. Part I: Kinematic parameters

  • Published:
pure and applied geophysics Aims and scope Submit manuscript

Abstract

This study is diagnostic in character and entails a systematic investigation of the kinematic parameters of the mean monthly 300 mb horizontal-motion field for the global tropical region during January, April, and October.

The kinematic parameters analysed include the horizontal velocity divergence, relative vorticity, velocity potential, and stream function. The magnitude of relative voritcity has been observed to be nearly equal to that of the horizontal velocity divergence in the equatorial latitudes and an order of magnitude larger in the subtropics. The magnitudes of∂u/∂x, ∂v/∂y, and horizontal velocity divergence are comparable and vary very little with latitude, while that of∂u/∂y is an order of magnitude larger than that of∂v/∂x, confirming its dominance in the computation of relative vorticity.

The latitudinal position of zero absolute vorticity isopleth fluctuates within 5 degrees of the equator and is confined more to the winter hemisphere than to the summer hemisphere.

The rotational component of wind is large compared with the divergent wind component. The magnitude of the rotational vector wind is four times that of the divergent vector wind in the equatorial latitudes and an order of magnitude larger in the subtropical latitudes.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

References

  • Corby, C. A. (1961),Some experiments in objective analysis of contour charts, Quart. J. Roy. Meteorol. Soc.87, 34–42.

    Article  Google Scholar 

  • Freeman, M. H. (1963),The computation of geostrophic winds by objective analysis, Met. Mag.92, 329–332.

    Google Scholar 

  • Gilchrist, B., andCressman, G. P. (1954),An experiment in objective analysis, Tellus6, 309–318.

    Article  Google Scholar 

  • Haltiner, G. H., andMartin, F. L.,Dynamical and Physical Meteorology (McGraw-Hill, New York 1957) pp. 381–382.

    Google Scholar 

  • Hawkins, H. F., andRosenthal, S. L. (1965),On the computation of stream functions from the wind field, Mon. Wea. Rev.93, 245–252.

    Google Scholar 

  • Hess, S. L.,Introduction to theoretical meteorology, (Holt, New York 1959), pp. 306–309.

    Google Scholar 

  • Krishnamurti, T. N., andRodgers, E. G. (1970),200 Millibar Wind Field June, July, August 1967, Report No. 70-2, (Dept. Meteorol. Florida State Univ., U.S.A.).

    Google Scholar 

  • Krishnamurti, T. N. (1971a),Tropical east-west circulations during the northern summer, J. Atmos. Sci.28, 1342–1347.

    Article  Google Scholar 

  • Krishnamurti, T. N. (1971b),Observational study of the tropical upper tropospheric motion field during the northern hemisphere summer, J. Appl. Met.10, 1066–1096.

    Article  Google Scholar 

  • Krishnamurti, T. N., Kanamitsu, M., Koss, W. J., andLee, J. (1973),Tropical east-west circulations during the northern winter, J. Atmos. Sci.30, 780–787.

    Article  Google Scholar 

  • Newell, R. E., Kidson, J. W., Vincent, D. G., andBoer, J. G.,The General Circulation of the Tropical Atmosphere and Interactions with Extra-Tropical Latitudes (MIT Press, Cambridge, Mass. 1972), Vol. 1, pp. 26–130.

    Google Scholar 

  • Ramanathan, Y., andBassi, M. R. (1976),Computation of divergence and vorticity from observed winds over the Indian region during monsoon, Indian J. Meteorol. Hydrol. Geophys.27, 409–416.

    Google Scholar 

  • Rayleigh, L. (1916),On the dynamics of revolving fluids, Proc. Roy. Soc. LondonA93, 148–154.

    Google Scholar 

  • Riehl, H.,Tropical Meteorology (McGraw-Hill, New York 1954), p. 392.

    Google Scholar 

  • Sadler, J. C. (1975),The Upper Tropospheric Circulation over the Global Tropics (Dept. Meteorology, Univ. Hawaii).

  • Sajnani, P. P. (1968),Use of Observed Winds for Computation of Divergence and Vorticity over India, InProc. WMO/IVGG Sym. Numer. Wea. Pred. (Tokyo), pt. VI, pp. 45–52.

  • Sangster, W. E. (1960),A method of representing the horizontal pressure force without reduction of station pressures to sea-level, J. Meteorol.17, 166–176.

    Google Scholar 

  • Solberg, H.,Le Mouvement d’Inertie de l’Atmosphère stable et son Rôle dans la Théorie de Cyclones, Memoir presented Meteor. Ass. UGGI, Lisbon, (Dupont Press 1933), pp. 66–82.

    Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Rights and permissions

Reprints and permissions

About this article

Cite this article

Pyuzza, N.D., Asnani, G.C. & Kiangi, P.M.R. An observational study of 300 mb winds in the tropical belt. Part I: Kinematic parameters. PAGEOPH 121, 655–683 (1983). https://doi.org/10.1007/BF02590160

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Issue Date:

  • DOI: https://doi.org/10.1007/BF02590160

Key words

Navigation