Abstract
TROPICAL heating associated with El Niño events influences weather patterns around the globe1–4, in part by generating wave-like disturbances of vorticity (a measure of local fluid circulation about the vertical) in the upper troposphere which extend into the mid-latitude regions. But these waves do not account well for the observed mid-latitude consequences of E1 Niño5–8 events. Here we show that a secondary interaction of these waves with mid-latitude mountains contributes significantly to the observed flow patterns. On encountering a mountain, a column of rotating air is compressed vertically, spreads horizontally, and its net vorticity is thereby reduced. For a realistic distribution of E1 Niño-related tropical heating, we find that vortex compression, primarily in the Himalayan–Tibetan region, generates a vorticity contribution at mid-latitudes with an amplitude up to one-half that of the directly propagating wave-train. Mountains therefore play a significant role in determining the structure of the extratropical response to E1 Niño.
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References
Bjerknes, J. Mon. Weath. Rev. 97, 163–172 (1969).
Ropelewski, C. F. & Halpert, M. S. Mon. Weath. Rev. 115, 1606–1629 (1987).
Hoskins, B. J. & Karoly, D. J. J. atmos. Sci. 38, 1179–1196 (1981).
Lau, N.-C. Mon. Weath. Rev. 113, 1970–1996 (1985).
Geisler, J. E., Blackmon, M. L., Bates, G. T. & Munoz, S. J. atmos. Sci. 42, 865–883 (1985).
Held, I. M. & Kang, I.-S. J. atmos. Sci. 44, 3576–3586 (1987).
Kok, C. J. & Opsteegh, J. D. J. atmos. Sci. 42, 677–694 (1985).
Held, I. M., Lyons, S. W. & Nigam, S. J. atmos. Sci. 46, 163–174 (1989).
Holton, J. R. An Introduction to Dynamic Meteorology (Academic, New York, 1992).
Sardeshmukh, P. D. & Hoskins, B. J. Q. J. R. met. Soc. 113, 339–360 (1987).
Schneider, E. K. Pure appl. Geophys. 126, 137–140 (1988).
Held, I. M. in Large-Scale Dynamical Processes in the Atmosphere (eds Hoskins, B. J. & Pearce, R. P.) 127–168 (Academic, New York, 1983).
Hoskins, B. J. & Ambrizzi, T. J. atmos. Sci. 50, 1661–1671 (1993).
Simmons, A. J., Wallace, J. M. & Branstator, G. J. atmos. Sci. 40, 1363–1392 (1983).
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DeWeaver, E., Nigam, S. Influence of mountain ranges on the mid-latitude atmospheric response to El Niño events. Nature 378, 706–708 (1995). https://doi.org/10.1038/378706a0
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DOI: https://doi.org/10.1038/378706a0
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