102 citations · 433 across the 29 of their papers we have counts for
29 papers
Solar Orbiter SEP Dropout during a Magnetic Cloud with Evidence for Strong Connectivity Gradients
Radoslav Bucik, Raul Gomez-Herrero, Samuel T. Hart +2
We analyze an impulsive solar energetic particle (SEP) event observed by Solar Orbiter at 0.93 au on 2022 December 24 that exhibits a pronounced intensity dropout between approxima…
Sunward Streaming 3He-rich SEP Events Observed by Solar Orbiter and Parker Solar Probe during Perihelion Passage
Samuel T. Hart, George C. Ho, Michael R. Terres +7
We report on two 3He-rich solar energetic particle (SEP) events observed by Solar Orbiter (SO) and Parker Solar Probe (PSP) during the April 1 - 4, 2024 conjunction when both space…
Helium-3 Enrichment in Gradual Solar Energetic Particle Events: Evidence for Jet-Supplied Seed Population
R. Bucik, S. T. Hart, M. A. Dayeh +3
Enhancements in 3He abundance, a characteristic feature of impulsive solar energetic particle (ISEP) events, are also frequently observed in gradual SEP (GSEP) events. Understandin…
Polytropic Behavior in Corotating Interaction Regions: Evidence of Alfvénic Heating
M. A. Dayeh, M. J. Starkey, G. Livadiotis +5
Corotating Interaction Regions (CIRs) are recurring structures in the solar wind, characterized by interactions between fast and slow solar wind streams that compress and heat plas…
Global Heliospheric Termination Shock Strength in the Solar-Interstellar Interaction
E. J. Zirnstein, R. Kumar, B. L. Shrestha +4
A heliospheric termination shock (HTS) surrounds our solar system at approximately 100 astronomical units from the Sun, where the expanding solar wind (SW) is compressed and heated…
Comparing Methods for Calculating Solar Energetic Particle Intensities: Re-binning versus Spectral Binning
M. E. Cuesta, L. Y. Khoo, G. Livadiotis +13
Solar energetic particle (SEP) events have been observed for decades in the interplanetary medium by spacecraft measuring the intensity of energetic ions and electrons. These inten…
Forecasting Shock-associated Energetic Particle Intensities in the Inner Heliosphere: A Proof-of-Concept Capability for the PUNCH Mission
Maher A. Dayeh, Michael J. Starkey, Heather A. Elliott +4
Solar energetic particles (SEPs) associated with shocks driven by fast coronal mass ejections (CMEs) or shocks developed by corotating interaction regions (CIRs) often extend to hi…
Origin of 3He abundance enhancements in gradual solar energetic particle events
Radoslav Bucik, Samuel T. Hart, Maher A. Dayeh +3
We examined the origin of 3He abundance enhancement in 23 high-energy (25-50 MeV) solar proton events that coincide with 3He-rich periods detected by ACE ULEIS in 1997-2021. In sev…
Magnetic reconnection-driven energization of protons up to 400 keV at the near-Sun heliospheric current sheet
M. I. Desai, J. F. Drake, T. Phan +22
We report observations of direct evidence of energetic protons being accelerated above ~400 keV within the reconnection exhaust of a heliospheric current sheet (HCS) crossing by NA…
CME Deflection and East-West Asymmetry of ESP Intensity in Solar Cycles 23 and 24
Adolfo Santa Fe Dueñas, Robert W. Ebert, Gang Li +4
We investigate the East-West asymmetry in energetic storm particle (ESP) heavy ion intensities at interplanetary shocks driven by coronal mass ejections (CMEs) during solar cycles…
MEMPSEP II. -- Forecasting the Properties of Solar Energetic Particle Events using a Multivariate Ensemble Approach
Maher A. Dayeh, Subhamoy Chatterjee, Andres Munoz-Jaramillo +3
Solar Energetic Particles (SEPs) form a critical component of Space Weather. The complex, intertwined dynamics of SEP sources, acceleration, and transport make their forecasting ve…
Variability of interplanetary shock and associated energetic particle properties as a function of the time window around the shock
Kimberly Moreland, Maher Dayeh, Gang Li +3
We study the effect of sampling windows on derived shock and associated energetic storm particle (ESP) properties in 296 fast-forward interplanetary shocks using ACE measurements a…
Investigating the IBEX Ribbon Structure a Solar Cycle Apart
Maher A. Dayeh, Eric J. Zirnstein, Pawel Swaczyna +1
A Ribbon of enhanced energetic neutral atom (ENA) emissions was discovered by the Interstellar Boundary Explorer (IBEX) in 2009, redefining our understanding of the heliosphere bou…
Solar Cycle Variation of 0.3-1.29 MeV/nucleon Heavy Ion Composition during Quiet Times near 1 AU in Solar Cycles 23 and 24
B. L. Alterman, Mihir I. Desai, Maher A. Dayeh +2
We report on the annual variation of quiet-time suprathermal ion composition for C through Fe using Advanced Composition Explorer (ACE)/Ultra-Low Energy Isotope Spectrometer (ULEIS…
Spherical Harmonic Representation of Energetic Neutral Atom Flux Components Observed by IBEX
P. Swaczyna, M. A. Dayeh, E. J. Zirnstein
The Interstellar Boundary Explorer (IBEX) images the heliosphere by observing energetic neutral atoms (ENAs). The IBEX-Hi instrument onboard IBEX provides full-sky maps of ENA flux…
On the seed population of solar energetic particles in the inner heliosphere
Nicolas Wijsen, Gang Li, Zheyi Ding +5
Particles measured in large gradual solar energetic particle (SEP) events are believed to be predominantly accelerated at shocks driven by coronal mass ejections (CMEs). Ion charge…
Modelling Solar Energetic Neutral Atoms from Solar Flares and CME-driven Shocks
Gang Li, Albert Y. Shih, Robert C. Allen +5
We examine the production of energetic neutral atoms (ENAs) in solar flares and CME-driven shocks and their subsequent propagation to 1 au. Time profiles and fluence spectra of sol…
The first gradual solar energetic particle event with enhanced 3He abundance on Solar Orbiter
R. Bučík, G. M. Mason, R. Gómez-Herrero +16
The origin of 3He abundance enhancements in coronal mass ejection (CME)-driven shock gradual solar energetic particle (SEP) events remains largely unexplained. Two mechanisms have…
Statistical Study and Live Catalogue of Multi-Spacecraft 3He-Rich Time Periods over Solar Cycles 23, 24, and 25
Samuel T. Hart, Maher A. Dayeh, Radoslav Bučík +5
Using ion measurements from Ultra-Low-Energy Isotope Spectrometer (ULEIS) observations onboard Advanced Composition Explorer (ACE) and Solar Isotope Spectrometer (SIS) observations…
Polytropic behavior in the structures of Interplanetary Coronal Mass Ejections
Maher A Dayeh, George Livadiotis
The polytropic process characterizes the thermodynamics of space plasma particle populations. The polytropic index, , is particularly important as it describes the thermodynamic…
Signature of a heliotail organized by the solar magnetic field and the role of non-ideal processes in modeled IBEX ENA maps: a comparison of the BU and Moscow MHD models
M. Kornbleuth, M. Opher, I. Baliukin +9
Energetic neutral atom (ENA) models typically require post-processing routines to convert the distributions of plasma and H atoms into ENA maps. Here we investigate how two differe…
Temperature in Solar Sources of 3He-rich Solar Energetic Particles and Relation to Ion Abundances
R. Bucik, S. M. Mulay, G. M. Mason +3
3He-rich solar energetic particles (SEPs) are believed to be accelerated in solar flares or jets by a mechanism that depends on the ion charge-to-mass (Q/M) ratio. It implies that…
Estimation of turbulent heating of solar wind protons at 1AU
George Livadiotis, Maher A. Dayeh, Gary P. Zank
The paper presents a new method for deriving turbulent heating of the solar wind using plasma moments and magnetic field data. We develop the method and then apply it to compute th…
Early-Stage SEP Acceleration by CME-Driven Shocks with Realistic Seed Spectra: I. Low corona
Kamen Kozarev, Maher A. Dayeh, Ashraf Farahat
An outstanding problem in heliospheric physics is understanding the acceleration of solar energetic particles (SEP) in coronal mass ejections (CMEs) and flares. A fundamental quest…