Deriving the strength and direction of the three-dimensional (3D) magnetic field in the solar atmosphere is fundamental for understanding its dynamics. Volume information on the magnetic field mostly relies on photospheric and/or chromospheric surface vector magnetic fields.

Solar magnetic activity exhibits variations with periods between 1.5–4 years, the so-called quasi-biennial oscillations (QBOs), in addition to the well-known 11-year Schwabe cycles. The solar dynamo is thought to be the responsible mechanism for the generation of the QBOs.

The NASA Global-scale Observations of the Limb and Disk (GOLD) ultraviolet spectrograph began imaging the Equatorial Ionization Anomaly (EIA), regions of the ionosphere with enhanced electron density north and south of the magnetic equator, in October 2018.

The second Miniature X-ray Solar Spectrometer (MinXSS-2) CubeSat builds on the success of MinXSS-1. The science instrument is more advanced – now capable of greater dynamic range with higher energy resolution.

The ability to predict conditions in Earth’s ionosphere and thermosphere is of increasing societal relevance due to the growing dependence on, for example, satellite based communications and navigation (e.g., GPS) systems.

We observe the abrupt end of solar activity cycles at the Sun’s Equator by combining almost 140 years of observations from ground and space.