Volume 40 Issue 6
Nov.  2020
Turn off MathJax
Article Contents
GUO Xiaocheng, CAO Shihao, XIONG Ming. Statistical Investigation on the Galactic Cosmic Rays and Solar Wind Variation Based on ACE Observations[J]. Journal of Space Science, 2020, 40(6): 969-979. doi: 10.11728/cjss2020.06.969
Citation: GUO Xiaocheng, CAO Shihao, XIONG Ming. Statistical Investigation on the Galactic Cosmic Rays and Solar Wind Variation Based on ACE Observations[J]. Journal of Space Science, 2020, 40(6): 969-979. doi: 10.11728/cjss2020.06.969

Statistical Investigation on the Galactic Cosmic Rays and Solar Wind Variation Based on ACE Observations

doi: 10.11728/cjss2020.06.969
  • Received Date: 2020-01-14
  • Rev Recd Date: 2020-09-25
  • Publish Date: 2020-11-15
  • Galactic Cosmic Rays (GCRs) are originated from the interstellar medium and modulated by the heliospheric magnetic field when they enter the heliosphere. Based on the GCR and plasma observations from ACE spacecraft, the relation between the GCR counts and the solar wind parameters during the recent two periods of solar minimum (the years of 2007.0-2009.0 and 2016.5-2019.0) was analyzed by means of the Superposed Epoch Analysis (SEA) method. The results indicate that GCRs are strongly modulated by the Corotating Interaction Regions (CIR) in solar wind, the Stream Interfaces (SI) sandwiched between fast and slow solar wind are closely related with the depression of GCR counts. The mechanism of the GCR variation is investigated through the empirical diffusion coefficients. The so-called "snow-plough" effect of GCR variation prior to the SI crossing appears during the first period, then the GCR counts decrease after the crossing, which corresponds to the sudden drop of diffusion coefficient at the SI. However, this effect is not observed for the second period, the decrease of GCR counts are simply caused by the enhancement of the diffusion coefficient after the SI crossing. Moreover, Heliospheric Current Sheet (HCS) correlate with GCR counts well, the GCRs drift along the current sheet and then accumulate to a pileup structure, which is physically balanced between their diffusion and drift effects. Finally, based on the observation and Parker transport theory, we discuss the physical mechanism of the GCR variation for the crossings of SIs and HCS, and proposed that the interplay between drift and diffusion determines the GCR distribution and variation at a heliocentric distance of 1AU.

     

  • loading
  • 加载中

Catalog

    通讯作者: 陈斌, bchen63@163.com
    • 1. 

      沈阳化工大学材料科学与工程学院 沈阳 110142

    1. 本站搜索
    2. 百度学术搜索
    3. 万方数据库搜索
    4. CNKI搜索

    Article Metrics

    Article views (392) PDF downloads(90) Cited by()
    Proportional views
    Related

    /

    DownLoad:  Full-Size Img  PowerPoint
    Return
    Return