Search Publications
Modeling solar energetic particle events using ENLIL heliosphere simulations
Futaana, Y.; Luhmann, J. G.; Odstrcil, D. +9 more
Solar energetic particle (SEP) event modeling has gained renewed attention in part because of the availability of a decade of multipoint measurements from STEREO and L1 spacecraft at 1 AU. These observations are coupled with improving simulations of the geometry and strength of heliospheric shocks obtained by using coronagraph images to send erupt…
Solar energetic particle warnings from a coronagraph
St. Cyr, O. C.; Burkepile, J. T.; Posner, A.
We report here the concept of using near-real time observations from a coronagraph to provide early warning of a fast coronal mass ejection (CME) and the possible onset of a solar energetic particle (SEP) event. The 1 January 2016, fast CME, and its associated SEP event are cited as an example. The CME was detected by the ground-based K-Cor corona…
SPRINTS: A Framework for Solar-Driven Event Forecasting and Research
Falconer, D. A.; Engell, A. J.; Schuh, M. +2 more
Capabilities to predict onset and time profiles of solar-driven events, including solar X-ray flares; solar energetic particles (SEP); coronal mass ejections; and high-speed streams, are critical in mitigating their potential impacts. We introduce the Space Radiation Intelligence System (SPRINTS). This NASA-invested technology integrates preerupti…
Predicting the magnetic vectors within coronal mass ejections arriving at Earth: 2. Geomagnetic response
Thompson, B. J.; Bothmer, V.; Richardson, I. G. +6 more
This is a companion to Savani et al. (2015) that discussed how a first-order prediction of the internal magnetic field of a coronal mass ejection (CME) may be made from observations of its initial state at the Sun for space weather forecasting purposes (Bothmer-Schwenn scheme (BSS) model). For eight CME events, we investigate how uncertainties in …
Seismic imaging of the Sun's far hemisphere and its applications in space weather forecasting
Lindsey, Charles; Braun, Douglas
The interior of the Sun is filled acoustic waves with periods of about 5 min. These waves, called "p modes," are understood to be excited by convection in a thin layer beneath the Sun's surface. The p modes cause seismic ripples, which we call "the solar oscillations." Helioseismic observatories use Doppler observations to map these oscillations, …
Real-time prediction of the occurrence of GLE events
Núñez, Marlon; Reyes-Santiago, Pedro J.; Malandraki, Olga E.
A tool for predicting the occurrence of Ground Level Enhancement (GLE) events using the UMASEP scheme is presented. This real-time tool, called HESPERIA UMASEP-500, is based on the detection of the magnetic connection, along which protons arrive in the near-Earth environment, by estimating the lag correlation between the time derivatives of 1 min …
Calculating travel times and arrival speeds of CMEs to Earth: An analytic tool for space weather forecasting
Aguilar-Rodriguez, E.; Corona-Romero, P.; Gonzalez-Esparza, J. A. +3 more
Coronal mass ejections (CME) are one of the most important phenomena derived from solar activity that potentially perturb space weather of Earth. In this work we present a semiempirical arrival forecasting tool for Earth-directed halo CMEs. This tool combines the piston shock model and an empirical relationship to estimate in situ arrivals of halo…
Faraday rotation fluctuations of MESSENGER radio signals through the equatorial lower corona near solar minimum
Jensen, E. A.; Heiles, C.; Hollweg, J. V. +4 more
Faraday rotation (FR) of transcoronal radio transmissions from spacecraft near superior conjunction enables study of the temporal variations in coronal plasma density, velocity, and magnetic field. The MESSENGER spacecraft 8.4 GHz radio, transmitting through the corona with closest line-of-sight approach 1.63-1.89 solar radii and near-equatorial h…
Automatic Near-Real-Time Detection of CMEs in Mauna Loa K-Cor Coronagraph Images
St. Cyr, O. C.; Burkepile, J. T.; Posner, A. +1 more
A simple algorithm has been developed to detect the onset of coronal mass ejections (CMEs), together with speed estimates, in near-real time using linearly polarized white-light solar coronal images from the Mauna Loa Solar Observatory K-Cor telescope. Ground observations in the low corona can warn of CMEs well before they appear in space coronagr…