Supergranulation supports waves

Laurent Gizon, T. L. Duvall

    Research output: Contribution to journalConference article

    Abstract

    Supergranulation on the surface of the Sun is a pattern of horizontal outflows with a distinct scale of 30 Mm and an apparent lifetime of 1 day, outlined by a network of small magnetic features. The dynamics of the supergranulation is poorly understood and there is as yet no explanation for the observation that the supergranular pattern appears to rotate faster than the magnetic features. In this paper we show that supergranulation undergoes oscillations and supports waves with periods of 6-9 days. The nature of supergranulation appears to be travelling-wave convection. Waves are predominantly prograde, which explains the apparent superrotation of the pattern. We also show that supergranular flows have a net kinetic helicity, which is negative in the northern hemisphere.

    Original languageEnglish (US)
    Pages (from-to)43-52
    Number of pages10
    JournalEuropean Space Agency, (Special Publication) ESA SP
    Issue number517
    StatePublished - Feb 1 2003
    EventPIC7 - Geneva, Switzerland
    Duration: Oct 30 2003Nov 3 2003

    Fingerprint

    superrotation
    Northern Hemisphere
    traveling waves
    Sun
    sun
    convection
    outflow
    oscillation
    life (durability)
    kinetics
    oscillations
    Kinetics
    Convection

    Keywords

    • Convection
    • Helioseismology
    • Magnetic fields
    • Supergranulation

    ASJC Scopus subject areas

    • Aerospace Engineering

    Cite this

    Supergranulation supports waves. / Gizon, Laurent; Duvall, T. L.

    In: European Space Agency, (Special Publication) ESA SP, No. 517, 01.02.2003, p. 43-52.

    Research output: Contribution to journalConference article

    Gizon, Laurent ; Duvall, T. L. / Supergranulation supports waves. In: European Space Agency, (Special Publication) ESA SP. 2003 ; No. 517. pp. 43-52.
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