Open AccessTranspolar Convection and Magnetospheric Ring Current Relations: Real‐Time Applications of the Polar Cap (PC) Indices
Author(s) -
Stauning Peter
Publication year - 2021
Publication title -
space weather
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.254
H-Index - 56
ISSN - 1542-7390
DOI - 10.1029/2020sw002702
Subject(s) - ring current , polar , index (typography) , ring (chemistry) , current (fluid) , function (biology) , physics , chemistry , computer science , magnetosphere , thermodynamics , magnetic field , organic chemistry , quantum mechanics , astronomy , evolutionary biology , biology , world wide web
Abstract 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.