Inaugural address. Stationary aspects of the tropical general circulation.
Main Article Content
Abstract
At first, the mean summer circulation is surveyed for three meteorological regimes near the surface and at 200 mb: the Atlantic trade, the Pacific trade and the Asiatic monsoon. There is a complete inversion of atmospheric structure comparing the trades with the monsoon. In the trades the lower winds are steady and diverging; at 200-mb high cyclonic vorticity along narrow shearlines with convergence is found. The air is cold relative to the surroundings in these shearlines. Frequently the flow is quite unsteady, with large or small cyclonic vortices travelling west along the shear line. The monsoon has the same structure, inverted. Here the steady easterlies with divergent anticyclonic flow are found in the high troposphere above the well known monsoon or equatorial low pressure trough with strong cyclonic shear and moving disturbances. Temperatures in the trough are very high, especially in the upper troposphere. Computations are performed to determine whether the stationary part of trade and monsoon regimes can provide for balance of heat, moisture and kinetic energy. It is found that this is the case and that unsteady flow features or forcing from extra tropical latitude~ need not be invoked to maintain the tropical summer circulation systems. In particular, the efficiency of conversion of latent heat release to production of kinetic energy by the mean circulation is found to be 2.5 per cent, about the same as computed for conversion of potential to kinetic energy in extratropical disturbances.
Article Details
This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.
References
ALAKA, M. A. 1958. A Case Study of an Easterly Jet Stream in the Tropics. Tellus, 10 : 24. DOI: https://doi.org/10.1111/j.2153-3490.1958.tb01983.x
BIGELOW, F. H. 1904. Results of the Nephoscope Observation in the West Indies during the Years 1899-1903. Mo. Wea. Rev., 32 : 166.
CRUTCHER, H. L. 1961. Meridional Cross Sections: Upper Winds over the Northern Hemisphere. U. S. Department of Commerce, Weather Burcau, Tech. Paper No. 41. (Washington, D. C.).
FICKER, H. 1936a. Veröff. Meteor. Inst. (Berlin), Vol. I, No.4.
----. 1936b. Preussische Akad. Wiss., Phys. Math. Kl. (Berlin), No. 11.
FLOHN, H. 1963. (In preparation).
GEORGII & SEILKOPF, 1926. Archiv d. Deutschen Seewarte, 17, Vol. 33.
JACOBS, W. C. 1951. The Energy Exchange between Sea and Atmosphere and some of its Consequences. Bull. Scripps Inst. Occanogr. Unit'. California, 6 : 27.
KOTESWARAM, P. 1958. The Subtropical Jet Stream of Summer. Tellus, 10 : 43. DOI: https://doi.org/10.1111/j.2153-3490.1958.tb01984.x
KRISHNAMURTI, T. N. 1961a. The Subtropical Jet Stream of Winter. Jour. Meteor., 18 : 172. DOI: https://doi.org/10.1175/1520-0469(1961)018<0172:TSJSOW>2.0.CO;2
----. 1961b. On the Role of the Subtropical Jet Stream of Winter in the Atmospheric General Circulation. Jour. Meteor., 18 : 657. DOI: https://doi.org/10.1175/1520-0469(1961)018<0657:OTROTS>2.0.CO;2
NEIBURGER, M. 1960. The Relation of Air Mass Structure to the Field of Motion over the Eastern North Pacific Ocean in Summer. Tellus, 11 : 21. DOI: https://doi.org/10.1111/j.2153-3490.1960.tb01281.x
PALMÉN, E. 1955. On the Mean Meridional Circulation in Low Latitudes of the Northern Hemisphere in Winter and the Associated Meridional and Vertical Flux of Angular Momentum. Soc. Sci. Fennica Comm., Phys.-Math., 17 (No.8).
PALMÉN, E., H. RIEHL, & L. A. VUORELA. 1958. On the Meridional Circulation and Release of Kinetic Energy in the Tropics. Jour. Meteorology, 15 : 271. DOI: https://doi.org/10.1175/1520-0469(1958)015<0271:OTMCAR>2.0.CO;2
PALMÉN, E. & L. A. VUORELA. 1963. On the Mean Meridional Circulations in the Northern Hemisphere during the Winter Season. Quart. Jour. Royal Meteor. Soc., 8 9 : 131. DOI: https://doi.org/10.1002/qj.49708937910
RIEHL, H. 1950. On the Role of the Tropics in the General Circulation of the Atmosphere. Tellus, 2 : 1. DOI: https://doi.org/10.1111/j.2153-3490.1950.tb00306.x
----. 1954. Tropical Meteorology. New York (McGraw Hill Book Co.), 392 pp.
RIEHL, H., T. C. YEH, J. S. MALKUS & N. E. LASEUR. 1951. The Northeast Trade of the Pacific Ocean. Quart. Jour. Royal Meteor. Soc., 77 : 598. DOI: https://doi.org/10.1002/qj.49707733405
RIEHL, H. & J. S. MALKUS, 1957. On the Heat Balance and Maintenance of Circulation in the Trades. Quart. Jour. Royal Meteor. Soc., 83 : 21. DOI: https://doi.org/10.1002/qj.49708335503
----. 1958. On the Heat Balance in the Equatorial Trough Zone. Geophysics, 6 : 503.
STONE, R. M. 1942. On the Mean Circulation of the Atmosphere over the Caribbean. Bull. American Meteor. Soc., 23 : 4. DOI: https://doi.org/10.1175/1520-0477-23.1.4
U. S. NAVY. 1956. Marine Climatic Atlas of the World, Vol. II : North Pacific Ocean. Washington, D. C. (U. S. Government Printing Office), 1 vol., il.
U. S. NAVY JOINT TASK FORCE SEVEN. 1961. Mean Monthly Upper Tropospheric Circulation over the Tropical Pacific during 1954-1959. Volume 4 : 1956. University of Hawaii, Meteorological Center, Honolulu, H. I.