Search Publications
Forecasting the Structure and Orientation of Earthbound Coronal Mass Ejections
Kilpua, E. K. J.; Temmer, M.; Mays, M. L. +1 more
Coronal Mass Ejections (CMEs) are the key drivers of strong to extreme space weather storms at the Earth that can have drastic consequences for technological systems in space and on ground. The ability of a CME to drive geomagnetic disturbances depends crucially on the magnetic structure of the embedded flux rope, which is thus essential to predic…
Benchmarking CME Arrival Time and Impact: Progress on Metadata, Metrics, and Events
Jian, L. K.; Temmer, M.; Dumbović, M. +9 more
Accurate forecasting of the arrival time and subsequent geomagnetic impacts of coronal mass ejections (CMEs) at Earth is an important objective for space weather forecasting agencies. Recently, the CME Arrival and Impact working team has made significant progress toward defining community-agreed metrics and validation methods to assess the current…
Spectral Analysis of the September 2017 Solar Energetic Particle Events
de Nolfo, G. A.; Christian, E. R.; Ryan, J. M. +2 more
An interval of exceptional solar activity was registered in early September 2017, late in the decay phase of solar cycle 24, involving the complex Active Region 12673 as it rotated across the western hemisphere with respect to Earth. A large number of eruptions occurred between 4 and 10 September, including four associated with X-class flares. The…
In Situ Data and Effect Correlation During September 2017 Solar Particle Event
Müller, D.; Vainio, R.; Sánchez-Cano, B. +28 more
Solar energetic particles are one of the main sources of particle radiation seen in space. In the first part of September 2017 the most active solar period of cycle 24 produced four large X-class flares and a series of (interplanetary) coronal mass ejections, which gave rise to radiation storms seen over all energies and at the ground by neutron m…
Modeling the Multiple CME Interaction Event on 6-9 September 2017 with WSA-ENLIL+Cone
Temmer, M.; Dimmock, A. P.; Yordanova, E. +1 more
A series of coronal mass ejections (CMEs) erupted from the same active region between 4-6 September 2017. Later, on 6-9 September, two interplanetary (IP) shocks reached L1, creating a complex and geoeffective plasma structure. To understand the processes leading up to the formation of the two shocks, we model the CMEs with the Wang-Sheeley-Arge (…
On Solutions of the PFSS Model With GONG Synoptic Maps for 2006-2018
Nikolić; , L.
The potential field source surface (PFSS) model is widely used to derive the magnetic field of the solar corona. The only free parameter in the PFSS model is the radius of the so-called source surface, where magnetic field lines are forced to open. The radius of this surface is typically set to 2.5 solar radii in research and operational PFSS nume…
Electron Intensity Measurements by the Cluster/RAPID/IES Instrument in Earth's Radiation Belts and Ring Current
Daly, P. W.; Kronberg, E. A.; Taylor, M. G. G. T. +7 more
The Cluster mission, launched in 2000, has produced a large database of electron flux intensity measurements in the Earth's magnetosphere by the Research with Adaptive Particle Imaging Detector (RAPID)/Imaging Electron Spectrometer (IES) instrument. However, due to background contamination of the data with high-energy electrons (>400 keV) and i…
Revising More Than 20 Years of EPHIN Ion Flux Data—A New Data Product for Space Weather Applications
Heber, B.; Kühl, P.
Solar energetic particle events and galactic cosmic rays are important aspects of space weather. Investigating them requires consistent measurements of electrons and ions over long time periods, that is, over more than a solar cycle. The Electron Proton Helium INstrument onboard the SOlar and Heliospheric Observatory is operational since 1995 and …
Testing Efficiency of Empirical, Adaptive, and Global MHD Magnetospheric Models to Represent the Geomagnetic Field in a Variety of Conditions
Sergeev, V. A.; Zheng, Y.; Tsyganenko, N. A. +1 more
We used data for eight magnetospheric spacecraft providing magnetic observations in various magnetospheric domains during a six-day time period, including the June 2015 storm, and a five-day period including the March 2015 storm. For these time intervals, containing different solar wind regimes and different activity levels, we used three types of…
Using Ghost Fronts Within STEREO Heliospheric Imager Data to Infer the Evolution in Longitudinal Structure of a Coronal Mass Ejection
de Koning, C. A.; Owens, M. J.; Scott, C. J. +3 more
Images of coronal mass ejections (CMEs) from the Heliospheric Imager instruments on board the Solar Terrestrial Relations Observatory (STEREO) spacecraft frequently contain rich structure. Here, we present analysis of the Earth-directed CME launched on 12 December 2008 in which we interpret the revealed structure as projections of separate discret…