Search Publications
Non-force-free extrapolation of solar coronal magnetic field using vector magnetograms
Gary, G. A.; Hu, Qiang; Büchner, J. +2 more
We report our recent improvement in non-force-free extrapolation of coronal magnetic field, using vector magnetograms. Based on the principle of minimum (energy) dissipation rate (MDR), a generally non-force-free magnetic field solution is expressed as the superposition of one potential field and two (constant-[alpha]) linear force-free fields, wi…
Analytical description of electric currents in the magnetosheath region
Veselovsky, I. S.; Vandas, M.; Romashets, E.
Volume currents in the magnetosheath region are calculated within the framework of a new analytical model. Magnetic field structure in the region is found, satisfying boundary conditions on the bow shock and the magnetopause, and then volume currents are calculated using the Maxwell equation. Surface bow shock and magnetopause currents are calcula…
Review of modeling of losses and sources of relativistic electrons in the outer radiation belt II: Local acceleration and loss
Meredith, Nigel P.; Shprits, Yuri Y.; Subbotin, Dmitriy A. +1 more
This paper focuses on the modeling of local acceleration and loss processes in the outer radiation belt. We begin by reviewing the statistical properties of waves that violate the first and second adiabatic invariants, leading to the loss and acceleration of high energy electrons in the outer radiation belt. After a brief description of the most c…
The development of new solar indices for use in thermospheric density modeling
Tobiska, W. Kent; Bouwer, S. Dave; Bowman, Bruce R.
New solar indices have been developed to improve thermospheric density modeling for research and operational purposes. Out of 11 new and 4 legacy indices and proxies, we have selected 3 (F10.7, S10.7, and M10.7) for use in the new JB2006 empirical thermospheric density model. In this work, we report on the development of these solar irradiance ind…
Solar cycle changes, geomagnetic variations, and energetic particle properties in the inner magnetosphere
Baker, D. N.; Kanekal, S. G.
The causes and effects of geospace variability during recent years have been studied using coordinated measurements from an international constellation of Sun-Earth spacecraft. Particular emphasis is placed on long-term, homogeneous data sets from recent NASA spacecraft missions. It is found that even for modest geomagnetic storms, radiation belt …
Magnetosphere ionosphere coupling during the CME events of 07 12 November 2004
Reme, H.; Walker, S.; Alleyne, H. +3 more
The response of the magnetosphere and ionosphere to the coronal mass ejection (CME) events during the period 07-12 November 2004 is studied using Cluster and ground-based (ESR, EISCAT and Jicamarca radars and magnetometer) observations. The coordinated observations provide a good example of the magnetosphere-ionosphere coupling through prompt pene…
An effort to derive an empirically based, inner-magnetospheric electric field model: Merging Cluster EDI and EFW data
Khotyaintsev, Y.; Matsui, H.; Jordanova, V. K. +2 more
A key ingredient for modelling many inner-magnetospheric processes is the realistic representation of the spatio-temporal dynamics of the inner-magnetospheric electric field, or, IMEF. The Cluster Mission provides a unique opportunity to construct an IMEF model using electric field measurements from both the electron drift instrument (EDI) and the…
Upstream whistler-mode waves at planetary bow shocks: A brief review
Russell, C.
Upstream whistler-mode waves appear to be present in front of all collisionless shocks. Because the whistler-mode group velocity exceeds its phase velocity over the frequency range in which the phase velocity increases with frequency, interesting alterations of polarization and frequency spectrum occur in the observer's reference frame. Landau res…
Present status and future challenges of modeling the Sun Earth end-to-end system
Baker, D. N.; Weigel, R. S.; Elkington, S. R. +1 more
Several research groups are presently modeling key portions of the solar terrestrial environment. Large-scale models of the solar corona, of the interplanetary medium, and of the coupled magnetosphere ionosphere system are providing important insights into the dynamics and temporal evolution of these regions during normal, as well as disturbed, co…
The evolution of shocks near the surface of Sun during the epoch of Halloween 2003
Wu, S. T.; Dryer, M.; Smith, Z. +4 more
We use a one-dimensional, time-dependent adaptive grid MHD code to study the evolution of shocks (both slow and fast shocks) from the surface of the Sun through the heliosphere. In order to achieve the goal, we track a specific solar event's plasma and magnetic field output as it propagates into interplanetary space with a possible geoeffective co…