The present study confirms the validity of previously derived relations between the polar cap (PC) indices and the ASY-H and the Dst and SYM-H ring current indices when used in real-time applications. PC indices are here derived in simulated real-time (SRT) versions by using past data only from −40 days up to current time in the construction of the quiet reference levels (QDCs) for the magnetic data. From analyses spanning a decade (2009–2018), equivalent ASY-H index values were derived from a linear relation with SRT PCN (North) and PCS (South) indices combined to form the non-negative PCC indices. For the cases of strong magnetic storms (Dst(peak )< −100 nT), the equivalent ASY-H indices were found to agree well with reported (real) ASY-H index values. The SRT PCC indices, furthermore, have been used in a PC-based source function to derive equivalent values of the total ring current indices Dst (or SYM-H) up to 1 h ahead of time. With integration of the source function throughout a decade (2009–2018) with no attachment to reported Dst values, the SRT equivalent Dst indices display close agreement with real Dst index values. The applied method could be used without modifications to generate PC index values and derived ASY-H and Dst (or SYM-H) index values in real-time space weather applications.

中文翻译：

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跨极对流和磁层环电流关系：极帽 (PC) 指数的实时应用

本研究证实了在实时应用中使用时，极冠 (PC) 指数与 ASY-H 以及 Dst 和 SYM-H 环电流指数之间先前导出的关系的有效性。PC 指数是在模拟实时 (SRT) 版本中通过仅使用从 -40 天到当前时间的过去数据得出的，用于构建磁数据的安静参考水平 (QDC)。根据跨越十年（2009-2018）的分析，等效的 ASY-H 指数值源自与 SRT PCN（北）和 PCS（南）指数的线性关系，组合形成非负 PCC 指数。对于强磁暴的情况（Dst（峰值）< -100 nT），发现等效的 ASY-H 指数与报告的（真实）ASY-H 指数值非常吻合。此外，SRT PCC 指数 已在基于 PC 的源函数中使用，以提前 1 小时导出总环电流指数 Dst（或 SYM-H）的等效值。随着源函数在整个十年（2009-2018 年）的整合，与报告的 Dst 值无关，SRT 等效 Dst 指数显示与实际 Dst 指数值非常吻合。所应用的方法无需修改即可用于在实时空间天气应用中生成 PC 指数值和导出的 ASY-H 和 Dst（或 SYM-H）指数值。