Observing and Modeling the Sun-Earth System

Solar prominences are cool, dense condensations suspended in the million-degree corona by stressed magnetic fields. Because these fields store free magnetic energy before space-weather-relevant eruptions, prominence morphology provides a visible probe of otherwise hidden pre-eruptive coronal structure. A persistent observational puzzle is why filament barbs, the lateral extensions of prominences, show a preferred bearing linked to the chirality of the filament channel. Here we use a three-dimensional magnetohydrodynamic simulation of a condensation-formed prominence in an emerged flux rope to show that barb chirality arises from the coupling of helical magnetic geometry and magnetic Rayleigh--Taylor interchange.

Aims: To derive convenient analytic estimations of magnetic inference errors, which can be used to inform and facilitate the creation of the science-traceability matrix of a polarimetric instrument.
Methods: We study the general problem of the propagation of Poissonian noise in polarized light signals to derived data products of the Stokes profiles, namely integral moments of arbitrary orders and spectral derivatives of the intensity. In particular, we derive the errors on the longitudinal and transversal projections of the magnetic field inferred from the weak-field approximation (WFA) of the Zeeman effect.

Solar eruptions are powered by magnetic energy stored in the Sun’s atmosphere, but the magnetic structure that exists before an eruption is difficult to determine. In particular, scientists debate whether solar filaments are supported by pre-existing, twisted magnetic flux ropes or by less twisted magnetic arcades that form flux ropes only during eruption. We developed a physics-informed method that reconstructs the three-dimensional magnetic field using measurements from both the Sun’s visible surface and the chromosphere above it.