Solar Physics and Space Weather
Group Head: Prof. Peter Gallagher
Schrödinger Fellow: Dr Eoin Carley
Refereed Publications: SAO/NASA Astrophysics Data System
Solar Radio Physics
The Sun is an active star that emits radiation across the electromagnetic spectrum. At radio wavelengths, large-scale eruptions can produce intense bursts of radio waves associated with accelerated electrons and shocks. In collaboration with Trinity College Dublin, we operate a number of instruments dedicated to studying solar radio bursts and their effects on Earth at the Rosse Observatory in Birr Castle, Co. Offaly, Ireland. The observatory includes the Irish Low Frequency Array , eCallisto solar radio burst monitors operating at 10-400 MHz, ionospheric monitors, and a magnetometer (the magnetometer is operated with DIAS Geophysics). We use these instruments in coordination with observations from spacecraft such as ESA/NASA’s Solar Orbiter and NASA’s Parker Solar Probe to study the Sun and its impacts on Earth and the wider Heliosphere.
Solar Orbiter is an ESA/NASA mission to examine how the Sun creates and controls the Heliosphere, the vast bubble of charged particles blown by the solar wind into the interstellar medium. The spacecraft combines in situ and remote sensing instruments to gain new information about the solar wind, the heliospheric magnetic field, solar energetic particles, transient interplanetary disturbances and the Sun’s magnetic field.
We are involved in writing software and scientific support for the Solar-Telescope Imaging X-rays (STIX) instrument. This instrument will enable us to obtain X-ray images and spectra emitted by solar flares and to study fundamental processes in solar flares, such as energy release and electron acceleration and propagation.
Solar Eruption Forecasting
Solar flares and coronal mass ejections originate in magnetic fields of the Sun’s atmosphere. Using measurements of the Sun’s surface magnetic field from spacecraft such as NASA’s Solar Dynamics Observatory, we develop methods to characterise and monitor magnetic fields in sunspots (e.g., via the Horizon 2020 FLARECAST project). These enable us to examine the changing topology of sunspots as they emerge, flare and decay. We are also developing techniques to improve the forecasting of solar flares using ensemble-based techniques, and investigating the first steps towards CME onset prediction using machine learning.
Solar wind streams and coronal mass ejections can cause storms in the Earth’s magnetosphere called geomagnetic storms. These storms can be associated with beautiful auroral displays but they can also cause unwanted electrical currents to flow through ground-based systems, such as power grids.
We have set up the Magnetometer Network of Ireland (MagIE) to monitor geomagnetic storms in near-realtime and to give warnings of geomagnetic storms in Ireland. We have also developed theoretical models to predict the electric fields and currents generated in response to magnetic variations across Ireland and the UK, in collaboration with the British Geological Survey and the UK Met Office.
SolarMonitor.org is a leading on-line tool which automatically reads, calibrates and displays solar data from numerous ground- and space-based observing platforms. SolarMonitor not only acts as a source for distributing data, but provides secondary products such as region flaring probabilities, which are essential to satellite operators, human space-flight, military operations, and the communications industry in general. We have received over 20 million visitors to the site since its launch.