ИСТИНА

All existing geomagnetic indices and interplanetary parameters characterize the steady-state level of the electrodynamics of near-Earth environment. Here we describe the construction, verification and introduction into space geophysics of a new hourly ULF wave index to characterize the turbulent level of the solar wind-magnetosphere-ionosphere system. The ground ULF index in frequency range of the Pc5 band (2-7 mHz) characterizing world-wide ULF activity is derived from 1-min data from array of magnetometers in the Northern hemisphere. A similar wave index is calculated from interplanetary monitor data to quantify the short-term outer space variability. These wave indices have been calculated since 1991 up to nowadays. A wide range of the space physics studies, such as substorm physics, relativistic electron energization, solar wind-ionosphere coupling, etc. will benefit from the introduction of the wave indices. The index database is freely available via the specially designed website for all interested researchers for testing, validation, and statistical studies. The work is partially supported by the RSF grant 16-17-00121.