Abstract The solar activity displays variability and periodic behaviours over a wide range of timescales, with the presence of a most prominent cycle with a mean length of 11 years. Such variability is transported within the heliosphere by solar wind, radiation and other processes, affecting the properties of the interplanetary medium. The presence of solar activity–related periodicities is well visible in different solar wind and geomagnetic indices, although their time lags with respect to the solar cycle lead to hysteresis cycles. Here, we investigate the time lag behaviour between a physical proxy of the solar activity, the Ca II K index, and two solar wind parameters (speed and dynamic pressure), studying how their pairwise relative lags vary over almost five solar cycles. We find that the lag between Ca II K index and solar wind speed is not constant over the whole time interval investigated, with values ranging from 6 years to 1 year (average 3.2 years). A similar behaviour is found also for the solar wind dynamic pressure. Then, by using a Lomb-Scargle periodogram analysis we obtain a 10.21-year mean periodicity for the speed and 10.30-year for the dynamic pressure. We speculate that the different periodicities of the solar wind parameters with respect to the solar 11-year cycle may be related to the overall observed temporal evolution of the time lags. Finally, by accounting for them, we obtain empirical relations that link the amplitude of the Ca II K index to the two solar wind parameters.


    Zugriff

    Zugriff prüfen

    Verfügbarkeit in meiner Bibliothek prüfen

    Bestellung bei Subito €


    Exportieren, teilen und zitieren



    Titel :

    On the time lag between solar wind dynamic parameters and solar activity UV proxies


    Beteiligte:
    Reda, R. (Autor:in) / Giovannelli, L. (Autor:in) / Alberti, T. (Autor:in)

    Erschienen in:

    Advances in Space Research ; 71 , 4 ; 2038-2047


    Erscheinungsdatum :

    2022-10-02


    Format / Umfang :

    10 pages




    Medientyp :

    Aufsatz (Zeitschrift)


    Format :

    Elektronische Ressource


    Sprache :

    Englisch




    Proxies for solar EUV in cycle 23

    Kane, R. P. | Online Contents | 2004


    Dayside Auroral Activity and Dependence from Solar Wind Parameters

    Orlando, A. / Massetti, S. / Zuccarello, F. et al. | British Library Conference Proceedings | 2006


    Relationship between the Parameters of Various Solar Wind Types and Geomagnetic Activity Indices

    Dremukhina, L. A. / Lodkina, I. G. / Yermolaev, Yu. I. | Online Contents | 2018


    Relationship between the Parameters of Various Solar Wind Types and Geomagnetic Activity Indices

    Dremukhina, L. A. / Lodkina, I. G. / Yermolaev, Yu. I. | Springer Verlag | 2018