The polar cap magnetic activity PC index is regarded as indicator of the solar wind energy that enters into the magnetosphere during the solar wind‐magnetosphere coupling (Resolutions of XXII IAGA Assembly, 2013). This study presents the results of statistical analysis of relationships between the yearly values of PC index and such indicators as the magnetic activity indices (AE and Dst), the solar wind parameters (velocity Vsw, density Nsw, dynamic pressure Pdyn, vertical interplanetary magnetic field (IMF) component Bz, total IMF field |B|, electric field E_KL), and the solar activity parameters (sunspot number, coronal mass ejections, stream interaction regions) in course of 23–24 solar cycles. It is shown that the yearly values of the quiet daily curve magnitude (which serves as a level of reference in estimation of the PC index value) changed during 1998–2019 in remarkable agreement with variation of the Solar UV irradiation (150–200 nm) absorbed in the Earth's ionosphere. The yearly values of PC index perfectly correlate with the yearly values of Vsw and |B| and their product electric field E_KL, as well as with the yearly values of AE and Dst indices testifying that PC index serves as the ground‐based indicator of the solar wind energy input into the magnetosphere. The yearly values of E_KL, PC, AE, Dst correlate with the total IMF field |B| much better that with the IMF Bz component, testifying that efficiency of the solar wind impact on the magnetosphere is defined by the total IMF value, in contrast with Dungey's concept of reconnection.

中文翻译：

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23/24太阳周期中PC指数的变化：与太阳风参数和磁层扰动的关系

极帽磁活动PC指数被视为在太阳风-磁层耦合过程中进入磁层的太阳风能的指标（XXII IAGA大会决议，2013）。这项研究提出了PC指数的年值与诸如磁活动指数（AE和Dst），太阳风参数（速度Vsw，密度Nsw，动压Pdy n，垂直行星际磁等）之间的关系的统计分析结果。场（IMF）分量Bz，总IMF场| B |，电场E _KL），以及在23–24个太阳周期内的太阳活动参数（黑子数，日冕物质抛射，水流相互作用区域）。结果表明，在1998-2019年期间，安静的日曲线幅度的年值（用作PC指数值的估计的参考水平）发生了变化，与太阳紫外线辐射（150-200 nm）的变化显着一致。被地球电离层吸收。的年值PC指数与每年的价值完全相关VSW和| B | 以及它们的乘积电场E _KL，以及证明该PC的AE和Dst指数的年值指数用作输入到磁层的太阳风能的地面指标。的年值ê _KL，PC，AE，Dst的与国际货币基金组织总场归属关系| B | 与使用IMF Bz组件相比，这要好得多，这证明了与Dungey的重新连接概念相反，太阳风对磁层的影响效率是由IMF的总值确定的。