Search Publications
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 …
Extreme relativistic electron fluxes in the Earth's outer radiation belt: Analysis of INTEGRAL IREM data
Meredith, Nigel P.; Horne, Richard B.; Sandberg, Ingmar +2 more
Relativistic electrons (E > 500 keV) cause internal charging and are an important space weather hazard. To assess the vulnerability of the satellite fleet to these so-called "killer" electrons, it is essential to estimate reasonable worst cases, and, in particular, to estimate the flux levels that may be reached once in 10 and once in 100 years…
Improving Empirical Magnetic Field Models by Fitting to In Situ Data Using an Optimized Parameter Approach
Brito, Thiago V.; Morley, Steven K.
A method for comparing and optimizing the accuracy of empirical magnetic field models using in situ magnetic field measurements is presented. The optimization method minimizes a cost function—τ—that explicitly includes both a magnitude and an angular term. A time span of 21 days, including periods of mild and intense geomagnetic activity, was used…
The substorm cycle as reproduced by global MHD models
Gordeev, E.; Sergeev, V.; Tsyganenko, N. +7 more
Recently, Gordeev et al. (2015) suggested a method to test global MHD models against statistical empirical data. They showed that four community-available global MHD models supported by the Community Coordinated Modeling Center (CCMC) produce a reasonable agreement with reality for those key parameters (the magnetospheric size, magnetic field, and…
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…
Vertical Thermospheric Density Profiles From EUV Solar Occultations Made by PROBA2 LYRA for Solar Cycle 24
Dominique, M.; Eparvier, F. G.; Thiemann, E. M. B. +1 more
A new data set of summed neutral N2 and O number density profiles, spanning altitudes between 150 and 400 km, and observed during Northern Winter from 2010 to 2016 is presented. The neutral density profiles are derived from solar occultation measurements made by the 0.1-20 nm Zr channel on the Large Yield Radiometer (LYRA) instrument on…
Nowcasting and forecasting of the magnetopause and bow shock—A status update
Petrinec, S. M.; Rastaetter, L.; Redmon, R. J.
There has long been interest in knowing the shape and location of the Earth's magnetopause and of the standing fast-mode bow shock upstream of the Earth's magnetosphere. This quest for knowledge spans both the research and operations arenas. Pertinent to the latter, nowcasting and near-term forecasting are important for determining the extent to w…
Magnetohydrodynamic simulation of interplanetary propagation of multiple coronal mass ejections with internal magnetic flux rope (SUSANOO-CME)
Kataoka, R.; Shiota, D.
Coronal mass ejections (CMEs) are the most important drivers of various types of space weather disturbance. Here we report a newly developed magnetohydrodynamic (MHD) simulation of the solar wind, including a series of multiple CMEs with internal spheromak-type magnetic fields. First, the polarity of the spheromak magnetic field is set as determin…