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Discussion of ‘thermals over the sea and gull flight behavior’ by A. H. Woodcock

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Abstract

Woodcock's (1975) refined plot of herring gull flight behavior on a diagram of wind speed versus sea-air temperature difference is shown to agree very satisfactorily with expectations derived from free-convection scaling arguments. However, his conclusion that under certain very weak wind conditions, a flock of gulls floating at sea can take off and quickly create a tall thermal suitable for soaring flight was not supported by a causal mechanism. A different hypothesis is that under those conditions, the gulls while on the sea surface can detect the near approach of a dominant thermal, as by sensing the occurrence of an essentially calm region marking the base of the updraft, and then can take off, circle, and quickly locate the nearby thermal.

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Authors and Affiliations

  1. National Center for Atmospheric Research, Boulder, Colorado, U.S.A.

    J. W. Deardorff

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  1. J. W. Deardorff
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The National Center for Atmospheric Research is sponsored by the National Science Foundation.

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Deardorff, J.W. Discussion of ‘thermals over the sea and gull flight behavior’ by A. H. Woodcock. Boundary-Layer Meteorol 10, 241–246 (1976). https://doi.org/10.1007/BF00229293

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  • DOI: https://doi.org/10.1007/BF00229293

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