Search Publications
CME Magnetic Structure and IMF Preconditioning Affecting SEP Transport
Lowrance, Patrick J.; Möstl, Christian; Guo, Jingnan +15 more
Coronal mass ejections (CMEs) and solar energetic particles (SEPs) are two phenomena that can cause severe space weather effects throughout the heliosphere. The evolution of CMEs, especially in terms of their magnetic structure, and the configuration of the interplanetary magnetic field (IMF) that influences the transport of SEPs are currently are…
A Multi-Purpose Heliophysics L4 Mission
Solanki, S. K.; Arge, C. N.; Henney, C. J. +13 more
The Earth-Sun Lagrangian point 4 is a meta-stable location at 1 AU from the Sun, 60° ahead of Earth's orbit. It has an uninterrupted view of the solar photosphere centered on W60, the Earth's nominal magnetic field connection to the Sun. Such a mission on its own would serve as a solar remote sensing observatory that would oversee the entire solar…
Evaluation of CME Arrival Prediction Using Ensemble Modeling Based on Heliospheric Imaging Observations
Dumbović, Mateja; Möstl, Christian; Weiss, Andreas J. +8 more
In this study, we evaluate a coronal mass ejection (CME) arrival prediction tool that utilizes the wide-angle observations made by STEREO's heliospheric imagers (HI). The unsurpassable advantage of these imagers is the possibility to observe the evolution and propagation of a CME from close to the Sun out to 1 AU and beyond. We believe that by exp…
Solar Origins of August 26, 2018 Geomagnetic Storm: Responses of the Interplanetary Medium and Equatorial/Low-Latitude Ionosphere to the Storm
Akala, A. O.; Oyedokun, O. J.; Amaechi, P. O. +3 more
This study investigates the solar origins of August 26, 2018 geomagnetic storm and the responses of the interplanetary medium and equatorial/low-latitude ionosphere to it. We used a multiinstrument approach, with observations right from the solar surface to the Earth. Our results showed that the G3 geomagnetic storm of August 26, 2018 was initiate…
Assessing the Projection Correction of Coronal Mass Ejection Speeds on Time of Arrival Prediction Performance Using the Effective Acceleration Model
Vourlidas, Angelos; Papaioannou, Athanasios; Anastasiadis, Anastasios +1 more
White light images of coronal mass ejections (CMEs) are projections on the plane of sky (POS). As a result, CME kinematics are subject to projection effects. The error in the true (deprojected) speed of CMEs is one of the main causes of uncertainty to Space Weather forecasts, since all estimates of the CME time of arrival (ToA) at a certain locati…
Why are ELEvoHI CME Arrival Predictions Different if Based on STEREO A or STEREO B Heliospheric Imager Observations?
Temmer, Manuela; Möstl, Christian; Weiss, Andreas J. +9 more
Accurate forecasting of the arrival time and arrival speed of coronal mass ejections (CMEs) is an unsolved problem in space weather research. In this study, a comparison of the predicted arrival times and speeds for each CME based, independently, on the inputs from the two STEREO vantage points is carried out. We perform hindcasts using ELlipse Ev…
Multi-Instrument Investigation of the Impact of the Space Weather Events of 6-10 September 2017
Simi, K. G.; Amaechi, Paul O.; Akala, Andrew O. +3 more
We analyzed the space weather events of 6-10 September 2017 using the multi-instrument approach. We focused on the four X-class flares which emanated from the Active Region AR 12673 and the Ground Induced Currents hazard associated with the geomagnetic storm of 7-8 September 2017. The flare effect on the equatorial electrojet (EEJ) recorded on boa…
Harmonization of RBSP and Arase Energetic Electron Measurements Utilizing ESA Radiation Monitor Data
Miyoshi, Yoshizumi; Shinohara, Iku; Mitani, Takefumi +11 more
Accurate measurements of trapped energetic electron fluxes are of major importance for the studies of the complex nature of radiation belts and the characterization of space radiation environment. The harmonization of measurements between different instruments increases the accuracy of scientific studies and the reliability of data-driven models t…
A Multicomponent Magnetic Proxy for Solar Activity
Warren, Harry P.; Upton, Lisa A.; Floyd, Linton E.
We present a new, multicomponent magnetic proxy for solar activity derived from full disk magnetograms that can be used in the specification and forecasting of the Sun's radiative output. To compute this proxy we project Carrington maps, such as the synchronic Carrington maps computed with the Advective Flux Transport (AFT) surface flux transport …
Solar EUV-Enhancement and Thermospheric Disturbances
Briand, C.; Doerksen, K.; Deleflie, F.
The increase of energetic electromagnetic flux during solar flares and particle precipitation during geomagnetic activity are among the most important sources of neutral density disturbances to the Earth's thermosphere. However, disentangling the role of X and EUV radiation during solar flares is difficult due to the rarity of sufficiently isolate…