Search Publications
On the role played by magnetic expansion factor in the prediction of solar wind speed
Riley, Pete; Linker, Jon A.; Arge, C. Nick
Over the last two decades, the Wang-Sheeley-Arge (WSA) model has evolved significantly. Beginning as a simple observed correlation between the expansion factor of coronal magnetic field lines and the measured speed of the solar wind at 1 AU (the Wang-Sheeley (WS) model), the WSA model now drives NOAA's first operational space weather model, provid…
Validation for solar wind prediction at Earth: Comparison of coronal and heliospheric models installed at the CCMC
Jian, L. K.; Odstrcil, D.; Riley, P. +6 more
Multiple coronal and heliospheric models have been recently upgraded at the Community Coordinated Modeling Center (CCMC), including the Wang-Sheeley-Arge (WSA)-Enlil model, MHD-Around-a-Sphere (MAS)-Enlil model, Space Weather Modeling Framework (SWMF), and heliospheric tomography using interplanetary scintillation data. To investigate the effects …
Predicting the magnetic vectors within coronal mass ejections arriving at Earth: 1. Initial architecture
Thompson, B. J.; Richardson, I. G.; Szabo, A. +6 more
The process by which the Sun affects the terrestrial environment on short timescales is predominately driven by the amount of magnetic reconnection between the solar wind and Earth's magnetosphere. Reconnection occurs most efficiently when the solar wind magnetic field has a southward component. The most severe impacts are during the arrival of a …
Ensemble Modeling of the 23 July 2012 Coronal Mass Ejection
Arge, C. N.; Henney, C. J.; Odstrcil, D. +5 more
On 23 July 2012 a significant and rapid coronal mass ejection (CME) was detected in situ by the Solar Terrestrial Relations Observatory (STEREO) A. This CME was unusual due to its extremely brief Sun-to-1 AU transit time of less than 21 h and its exceptionally high impact speed of 2246 km/s. If this CME had been Earth directed, it would have produ…
Ensemble forecasting of major solar flares: First results
Pulkkinen, A.; Guerra, J. A.; Uritsky, V. M.
We present the results from the first ensemble prediction model for major solar flares (M and X classes). The primary aim of this investigation is to explore the construction of an ensemble for an initial prototyping of this new concept. Using the probabilistic forecasts from three models hosted at the Community Coordinated Modeling Center (NASA-G…
Theoretical basis for operational ensemble forecasting of coronal mass ejections
Odstrcil, D.; Biesecker, D. A.; Millward, G. +5 more
We lay out the theoretical underpinnings for the application of the Wang-Sheeley-Arge-Enlil modeling system to ensemble forecasting of coronal mass ejections (CMEs) in an operational environment. In such models, there is no magnetic cloud component, so our results pertain only to CME front properties, such as transit time to Earth. Within this fra…
Dynamic SEP event probability forecasts
Kahler, S. W.; Ling, A.
The forecasting of solar energetic particle (SEP) event probabilities at Earth has been based primarily on the estimates of magnetic free energy in active regions and on the observations of peak fluxes and fluences of large (≥ M2) solar X-ray flares. These forecasts are typically issued for the next 24 h or with no definite expiration time, which …