Highlights ► SSC spectrum contains high power components over all frequency ranges. ► For the first time, SSC automatic detector uses high resolution data is introduced. ► Small detection error and processing time could be achieved using one-second data. ► DWT is a good tool to build an SSC automatic detection.

    Abstract Geomagnetic storm sudden commencements (SSC) contain a wealth of information which is useful in many applications. It is important to point out that the SSCs used in this study are sampled at the rate of one sample per second in order get use of such high resolution data. In this paper, two studies are made on the geomagnetic SSC and an SSC onset automatic detection algorithm is introduced. The first study is about finding the relationship between the SSC rise time and its amplitude. Where it is found that there is a positive correlation between the amplitude and the amplitude gradient which is the amplitude divided by rise time. The second study is checking the spectrum of the SSC, starting from its onset until the end of the SSC rise time. This check had proved that the SSC contains both low and high frequency regions. This led us to introduce a new term, namely the SSC variation rate (VR). This VR is defined as the maximum rate of change of the field in the higher-frequency region of the SSC. These two studies were the guide to build an SSC automatic detector of one sample per second data using multi resolution analysis (MRA) of the discrete wavelet transform (DWT). The data set contains 134 SSCs with different VRs that were collected from the Circum-pan Pacific Magnetometer Network (CPMN). It is found that the standard deviation of the detection error is 41s and that the average error is 9s. From the calculated error distribution function, it is found that the detection error is within the range of −1.5 to 3min. The detection process, as will be shown in the article, takes 70s for one station and 3min if the decision is related to the detection(s) of other stations. These results demonstrate the superiority of the proposed algorithm over other algorithms in which the detection error ranges between −8 and 5min and the detection process takes 2–10min. In addition to being faster and more accurate than the other algorithms, the proposed algorithm is the first algorithm that automatically detects the SSC onset times from high-resolution data unlike previous studies that focused on determining the SSC times automatically using one-minute resolution data.


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    Titel :

    Systematic examination of the geomagnetic storm sudden commencement using multi resolution analysis


    Beteiligte:
    Hafez, Ali G. (Autor:in) / Ghamry, Essam (Autor:in) / Yayama, Hideki (Autor:in) / Yumoto, Kiyohumi (Autor:in)

    Erschienen in:

    Erscheinungsdatum :

    2012-07-30


    Format / Umfang :

    11 pages




    Medientyp :

    Aufsatz (Zeitschrift)


    Format :

    Elektronische Ressource


    Sprache :

    Englisch