Russian Journal of Earth Sciences Russian Journal of Earth Sciences Russian Journal of Earth Sciences 1681-1208 71816 10.2205/2025ES001089 ibegvg ОРИГИНАЛЬНЫЕ СТАТЬИ ORIGINAL ARTICLES ОРИГИНАЛЬНЫЕ СТАТЬИ New Regional Geomagnetic Indices for the Russian Sector of the Geomagnetic Observation Network New Regional Geomagnetic Indices for the Russian Sector of the Geomagnetic Observation Network https://orcid.org/0000-0002-9680-5609 Воробьев Андрей Владимирович Vorobev Andrey Vladimirovich geomagnet@list.ru

доктор технических наук;

doctor of technical sciences;

 https://orcid.org/0000-0003-3056-7465 Пилипенко Вячеслав Анатольевич Pilipenko Vyacheslav Anatolievich pilipenko_va@mail.ru

доктор физико-математических наук;

doctor of physical and mathematical sciences;

 https://orcid.org/0000-0001-6930-3331 Добровольский Михаил Николаевич Dobrovolsky Michael Nikolaevich m.dobrovolsky@gcras.ru https://orcid.org/0000-0003-0825-151X Козырева Ольга Васильевна Kozyreva Olga Vasilyevna kozyreva@ifz.ru

доктор физико-математических наук;

doctor of physical and mathematical sciences;

 https://orcid.org/0009-0001-0828-2896 Евдокимова Марина Александровна Evdokimova Marina Alexandrovna evdokimova@iki.rssi.ru https://orcid.org/0000-0002-9174-224X Кудин Дмитрий Владимирович Kudin Dmitriy Vladimirovich Уфимский университет науки и технологий Уфа Россия Ufa University of Science and Technology Ufa Russian Federation Геофизический центр Российской Академии Наук RU Geophysical Center of the Russian Academy of Sciences RU Институт физики Земли им. О.Ю. Шмидта Российской академии наук Moscow Россия Schmidt Institute of Physics of the Earth of the Russian Academy of Sciences Moscow Russian Federation Институт физики Земли им. О.Ю. Шмидта РАН Москва Россия Schmidt Institute of Physics of the Earth, RAS Moscow Russian Federation Институт космических исследований РАН Москва Россия Space Research Institute of the Russian Academy of Sciences Moscow Russian Federation Геофизический центр РАН Москва Россия Geophysical Center of the Russian Academy of Sciences Moscow Russian Federation 30 12 2025 30 12 2025 25 6 ES6016 21 11 2023 21 11 2025 https://rjes.ru/en/nauka/article/71816/view

It was proposed to introduce new regional geomagnetic indices SME-R and VAR characterizing the values of the geomagnetic field perturbation and its variability (i.e., dB/dt) in the Russian sector at auroral latitudes into space weather studies. The indices are calculated from data of the Russian magnetic stations at geomagnetic latitudes from 40° to 70°. We compared the unofficial and regional indices with the standard planetary indices during some magnetic storms of 2015. In addition to the official IAGA indices Dst/ SYM-H, AE, PC, modified and regional indices SME, PC-n, ULF, EI, Wp (Pi2) were considered. The analysis of these events showed that some auroral activations confidently distinguished by the SME index can be missed by the standard AE index. The discrepancy between the standard PC and the refined PC-n indices reaches 1 mV/m to 2 mV/m during strong perturbations. The variability of the magnetic field characterized by the VAR index is not uniquely related to the level of geomagnetic perturbation characterized by the AE or SME-R indices. The events considered show that the use of planetary indices to estimate regional space weather perturbations can lead to false conclusions. The database of standard, modified, and new regional indices for 2015 is freely available at the FTP site ftp://indexguest:indexguest@imagftp.gcras.ru/ for testing.

It was proposed to introduce new regional geomagnetic indices SME-R and VAR characterizing the values of the geomagnetic field perturbation and its variability (i.e., dB/dt) in the Russian sector at auroral latitudes into space weather studies. The indices are calculated from data of the Russian magnetic stations at geomagnetic latitudes from 40° to 70°. We compared the unofficial and regional indices with the standard planetary indices during some magnetic storms of 2015. In addition to the official IAGA indices Dst/ SYM-H, AE, PC, modified and regional indices SME, PC-n, ULF, EI, Wp (Pi2) were considered. The analysis of these events showed that some auroral activations confidently distinguished by the SME index can be missed by the standard AE index. The discrepancy between the standard PC and the refined PC-n indices reaches 1 mV/m to 2 mV/m during strong perturbations. The variability of the magnetic field characterized by the VAR index is not uniquely related to the level of geomagnetic perturbation characterized by the AE or SME-R indices. The events considered show that the use of planetary indices to estimate regional space weather perturbations can lead to false conclusions. The database of standard, modified, and new regional indices for 2015 is freely available at the FTP site ftp://indexguest:indexguest@imagftp.gcras.ru/ for testing.

 Geomagnetic indices substorm geomagnetic variations geoinduced currents Geomagnetic indices substorm geomagnetic variations geoinduced currents This work was carried out in the framework of budgetary funding of the Geophysical Center of RAS, adopted by the Ministry of Science and Higher Education of the Russian Federation. We express our gratitude to P. Stauning for providing the database of PC-n indices, R. McPherron – for the catalog of substorm onset by MBP index. The results presented in this paper rely on data collected at magnetic observatories. We thank the national institutes that support them and INTERMAGNET for promoting high standards of magnetic observatory practice (http://www.intermagnet.org). This work employed facilities and data provided by the Shared Research Facility “Analytical Geomagnetic Data Center” of the Geophysical Center of RAS (http://ckp.gcras.ru/). This work was carried out in the framework of budgetary funding of the Geophysical Center of RAS, adopted by the Ministry of Science and Higher Education of the Russian Federation. We express our gratitude to P. Stauning for providing the database of PC-n indices, R. McPherron – for the catalog of substorm onset by MBP index. The results presented in this paper rely on data collected at magnetic observatories. We thank the national institutes that support them and INTERMAGNET for promoting high standards of magnetic observatory practice (http://www.intermagnet.org). This work employed facilities and data provided by the Shared Research Facility “Analytical Geomagnetic Data Center” of the Geophysical Center of RAS (http://ckp.gcras.ru/).

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