Summary
Using ECMWF analyses and daily rain amounts of 569 stations in Western Africa for summer 1989, the study documents the composite structure of the 6–9 day oscillation and its influence on rain. Rain is modulated by vorticity as displayed in the wave composite. There are rainfall maxima coincident with cyclonic vorticity and rainfall minima coincident with anticyclonic vorticity at the 700hPa level, at 17.5°N and 7.5°N.
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References
Burpe, R. W., 1975: Some features of synoptic-scale waves based on a compositing analysis of GATE data.Mon. Wea. Rev.,103, 921–925.
Chang, C. P., Chen, J. M., Harr, P. A., Carr, L. E., 1996: Northwestward propagating wave patterns over the tropical western north Pacific during summer.Mon. Wea. Rev.,124, 2245–2266.
De Félice, P., Viltard, A., Monkam, D., Ouss, C., 1990: Characteristics of North African 6–9 day waves during summer 1981.Mon. Wea. Rev.,118, 2624–2633.
De Félice, P., Viltard, A., Oubuih, J., 1993: A synoptic-scale wave of 6–9 day period in the Atlantic tropical troposphere during summer 1981.Mon. Wea. Rev.,121, 1291–1298.
Krishnamurti, T. N., Subramaniam, M., Oosterhof, D. K., Daughenbough, G., 1990: Predictability of low frequency modes.Meteorol. Atmos. Phys.,44, 63–83.
Nicholson, S. E., Kim, J., Hoopingarner, J., 1988:Atlas of African Rainfall and its Interannual Variability. Department of Meteorology. The Florida State University Tallahassee, Florida 32306, 237 p.
Reed, R. J., Recker, E. E., 1977: Structures and properties of synoptic-scale wave disturbances in the equatorial western Pacific.J. Atmos. Sci.,128, 1117–1133.
Reed, R. J., Norquist, D. C., Recker, E. E., 1977: The structure and properties of African wave disturbances as observed during Phase III of GATE.Mon. Wea. Rev.,105, 317–333.
Riehl, H., 1948: On the formation of typhoons.J. Meteor.,5, 247–264.
Viltard, A., de Félice, P., 1997: Comparison of the African and 6–9 day wave-like disturbances patterns over West-Africa and the tropical Atlantic during summer 1985.Meteorol. Atmos. Phys.,62, 91–99.
Yanaï, M. O., Murakami, M., 1970: Spectrum analysis of symmetric antisymmetric equatorial waves.J. Meteor. Soc. Japan,48, 331–346.
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Viltard, A., Oubuih, J., de Felice, P. et al. Rainfall and the 6–9 day wave-like disturbance in West-Africa during summer 1989. Meteorl. Atmos. Phys. 66, 229–234 (1998). https://doi.org/10.1007/BF01026635
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DOI: https://doi.org/10.1007/BF01026635