Studying Sun–Planet Connections Using the Heliophysics Integrated Observatory (HELIO)

Abstract

The Heliophysics Integrated Observatory (HELIO) is a software infrastructure involving a collection of web services, heliospheric data sources (e.g., solar, planetary, etc.), and event catalogues -all of which are accessible through a unified front end. In this paper we use the HELIO infrastructure to perform three case studies based on solar events that propagate through the heliosphere. These include a coronal mass ejection that intersects both Earth and Mars, a solar energetic particle event that crosses the orbit of Earth, and a high-speed solar wind stream, produced by a coronal hole, that is observed in situ at Earth (L1). A ballistic propagation model is run as one of the HELIO services and used to model these events, predicting if they will interact with a spacecraft or planet and determining the associated time of arrival. The HELIO infrastructure streamlines the method used to perform these kinds of case study by centralising the process of searching for and visualising data, indicating interesting features on the solar disk, and finally connecting remotely observed solar features with those detected by in situ solar wind and energetic particle instruments. HELIO represents an important leap forward in European heliophysics infrastructure by bridging the boundaries of traditional scientific domains.

SunPy—Python for solar physics

“…The HELiophysics Integrated Observatory (HELIO) ‡ has compiled a list of web services which allows scientists to query and discover data throughout the heliosphere, from solar and magnetospheric data to planetary and inter-planetary data (Pérez-Suárez et al, 2012). HELIO is built with a Service-Oriented Architecture, i.e., its capabilities are divided into a number of tasks that are implemented as separate services.…”

HELIO: Discovery and analysis of data in heliophysics

“…The uncertainty is compensated for by expanding the search volume and lengthening the search time-slot; in effect, this is attaching an estimate of error to the spacetime location that the propagation model itself produces. The Solar-Heliospheric Event Ballistic Algorithm (SHEBA) [19] has been developed within HELIO as a first approximation to solve the propagation problem. This algorithm, built on top of HELIO services, offers three different propagation modes (i.e., CMEs, SIRs and high energetic particles) through a simple 2D ballistic propagation model [20].…”

“…SHEBA allows to run the propagation in two directions, from the Sun outwards into the heliosphere, and from any object (planet or spacecraft) backwards to the Sun. Though SHEBA is a basic propagation model, it has shown satisfactory results for noncomplex events (e.g., an individual CME propagating in a quiet environment) [19].…”

Extending the Sheba Propagation Model to Reduce Parameter-Related Uncertainties

“…SHEBA is not data driven and it uses a simple ballistic model, i.e., all the propagation is done assuming a constant speed, though this approximation could seem very inaccurate, it has been shown that it is not far from reality during quiet periods [13]. The main aim in SHEBA was to offer a fast and easy propagation model to the users of HELIO.…”

“…The HELIO project [4,7,8,14] has developed SHEBA [13], a Propagation Model of the ballistic kind. Depending on whether it is run from the Sun to the planets or vice-versa and on which phenomena is investigated, SHEBA requires information on a variety of parameters such as the position on the surface on the Sun from where the event originates, its time and its expected speed at the source.…”