Browsing UMBC Goddard Planetary Heliophysics Institute (GPHI) by Title
Now showing items 1-20 of 115
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The 04 – 10 September 2017 Sun–Earth Connection Events: Solar Flares, Coronal Mass Ejections/Magnetic Clouds, and Geomagnetic Storms
(Springer Netherlands, 2019-08-23)In early September 2017, a series of solar flares and coronal mass ejections (CMEs) erupted from the Sun. The Cor2a coronagraph, a unit of the Sun Earth Connection Coronal and Heliospheric Investigation (SECCHI), onboard ... -
3D Space-Time Adaptive Hybrid Simulations of Magnetosheath High-Speed Jets
(American Geophysical Union, 2021-06-18)Abstract We study the generation and evolution of spatially localized dynamic plasma pressure enhancements in the magnetosheath (high-speed jets) by carrying out three-dimensional hybrid simulations of the Earth's dayside ... -
An alternative drift shell parameter for modeling trapped particles
(Elsevier, 1999-11-08)The McIlwain L parameter has been widely used to label magnetic drift shells of trapped particles. In a dipolar magnetic field, L gives the equatorial radius of a drift shell. When the total magnetospheric magnetic field ... -
An analysis of the Trouvelot’s Auroral Drawing on 1/2 March 1872: Plausible Evidence for Recurrent Geomagnetic Storms
(AGU Pubication, 2020-06-22)This work examines Trouvelot’s observations and drawing of an auroral display during the night of 1 March 1872. It is known that the auroral oval moves equatorward to mid‐ and even low‐latitudes during large geomagnetic ... -
Assessment of observational evidence for direct convective hydration of the lower stratosphere
(AGU Pubication, 2020-06-23)In situ and remote‐sensing observations of water vapor are analyzed to assess the evidence for direct convective hydration of the lower stratosphere. We have examined several hundred balloon‐borne and airborne in situ ... -
Bulk Flow Velocity and First-Order Anisotropy of Solar Energetic Particles Observed on the Wind Spacecraft: Overview of Three "Gradual" Particle Events
(IOP Publishing, 2007-02-17)We have developed techniques to calculate bulk flow velocity and first-order anisotropy of solar energetic particles (SEPs) with MeV nucleon-1 energies as recorded on the Wind spacecraft. Using the techniques we selected ... -
A Case Study of Nonresonant Mode 3-s ULF Waves Observed by MMS
(American Geophysical Union, 2020-11-16)The nature of the 3-s ultralow frequency (ULF) wave in the Earth's foreshock region and the associated wave-particle interaction are not yet well understood. We investigate the 3-s ULF waves using Magnetospheric Multiscale ... -
Cluster After 20 Years of Operations: Science Highlights and Technical Challenges
(AGU, 2021-07-20)The Cluster mission was the first constellation using four identical spacecraft to study Sun-Earth connection plasma processes. Using four spacecraft in a tetrahedron shape, it could measure, for the first time, 3D quantities ... -
Clustering of Intermittent Magnetic and Flow Structures near Parker Solar Probe's First Perihelion—A Partial-variance-of-increments Analysis
(AAS, 2020-02-03)During the Parker Solar Probe's (PSP) first perihelion pass, the spacecraft reached within a heliocentric distance of ∼37 R⊙ and observed numerous magnetic and flow structures characterized by sharp gradients. To better ... -
Concerning the interaction of a transmitted interplanetary impulse with a plasmaspheric drainage plume: First results from 3-D hybrid kinetic modeling
(Elsevier, 2020-09-25)We present a new hybrid kinetic model to simulate the response of plasmaspheric drainage plumes to impulsive interplanetary pressure pulses. Since particle distributions attending the interplanetary pulses and in the ... -
Current sheets and pressure anisotropy in the reconnection exhaust
(AIP Publishing, 2014-01-14)A particle-in-cell simulation shows that the exhaust during anti-parallel reconnection in the collisionless regime contains a current sheet extending 100 inertial lengths from the X line. The current sheet is supported by ... -
The Current State and Future Directions of Modeling Thermosphere Density Enhancements During Extreme Magnetic Storms
(Frontiers, 2021-10-29)Satellites, crewed spacecraft and stations in low-Earth orbit (LEO) are very sensitive to atmospheric drag. A satellite’s lifetime and orbital tracking become increasingly inaccurate or uncertain during magnetic storms. ... -
Deciphering Solar Magnetic Activity. II. The Solar Cycle Clock and the Onset of Solar Minimum Conditions
The Sun's variability is controlled by the progression and interaction of the magnetized systems that form the 22-year magnetic activity cycle (the "Hale Cycle") as they march from their origin at ∼55 degrees latitude to ... -
Deciphering Solar Magnetic Activity: 140 Years Of The ‘Extended Solar Cycle’ – Mapping the Hale Cycle
The cyclic, enigmatic, and ubiquitous magnetism of the Sun provides the energy we need to survive and has the ability to destroy our technologically dependent civilization. Never before has understanding solar magnetism ... -
Deriving Large Coronal Magnetic Loop Parameters Using LOFAR J burst Observations
(Springer, 2022-12-05)Large coronal loops around one solar radius in altitude are an important connection between the solar wind and the low solar corona. However, their plasma properties are ill-defined as standard X-ray and UV techniques are ... -
Developing the Physical Understanding of Intermediate Polars: An X-Ray Study of TV Col and V2731 Oph
(IOP Publishing, 2019-08-02)The X-rays in intermediate polars (IPs) originate in a compact region near the surface of a magnetic white dwarf (WD) and interact with the complex environment surrounding the emission region. Here we report a case study ... -
Development of a magnetospheric state-based trapped radiation database
(Elsevier, 2005-07-05)At the core of any empirical trapped radiation model is a database containing energetic particle observations. The usefulness of such a database and the performance of the resulting models depend on the database flexibility ... -
Direct observations of energy transfer from resonant electrons to whistler-mode waves in magnetosheath of Earth
(Nature, 2022-10-28)Electromagnetic whistler-mode waves in space plasmas play critical roles in collisionless energy transfer between the electrons and the electromagnetic field. Although resonant interactions have been considered as the ... -
Drift Instabilities in Thin Current Sheets Using a Two-Fluid Model With Pressure Tensor Effects
(American Geophysical Union, 2019-04-15)The integration of kinetic effects in fluid models is important for global simulations of the Earth's magnetosphere. We use a two-fluid 10-moment model, which includes the pressure tensor and has been used to study ... -
Electron vorticity indicative of the electron diffusion region of magnetic reconnection
(American Geophysical Union, 2019-06-27)Abstract While vorticity defined as the curl of the velocity has been broadly used in fluid and plasma physics, this quantity has been underutilized in space physics due to low time resolution observations. We report ...