An adaptively-refined Cartesian mesh solver for the Euler equations

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76176/1/AIAA-1991-1542-927.pd

Euler calculations of axisymmetric under-expanded jets by an adaptive-refinement method

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76884/1/AIAA-1992-321-143.pd

A wave-model-based refinement criterion for adaptive-grid computation of compressible flows

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76980/1/AIAA-1992-322-216.pd

Development and validation of solution-adaptive, parallel schemes for compressible plasmas

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76300/1/AIAA-2001-2525-679.pd

A parallel solution-adaptive scheme for ideal magnetohydrodynamics

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/77232/1/AIAA-1999-3273-200.pd

Ionospheric control of the dawn‐dusk asymmetry of the Mars magnetotail current sheet

This study investigates the role of solar EUV intensity at controlling the location of the Mars magnetotail current sheet and the structure of the lobes. Four simulation results are examined from a multifluid magnetohydrodynamic model. The solar wind and interplanetary magnetic field (IMF) conditions are held constant, and the Mars crustal field sources are omitted from the simulation configuration. This isolates the influence of solar EUV. It is found that solar maximum conditions, regardless of season, result in a Venus‐like tail configuration with the current sheet shifted to the −Y (dawnside) direction. Solar minimum conditions result in a flipped tail configuration with the current sheet shifted to the +Y (duskside) direction. The lobes follow this pattern, with the current sheet shifting away from the larger lobe with the higher magnetic field magnitude. The physical process responsible for this solar EUV control of the magnetotail is the magnetization of the dayside ionosphere. During solar maximum, the ionosphere is relatively strong and the draped IMF field lines quickly slip past Mars. At solar minimum, the weaker ionosphere allows the draped IMF to move closer to the planet. These lower altitudes of the closest approach of the field line to Mars greatly hinder the day‐to‐night flow of magnetic flux. This results in a buildup of magnetic flux in the dawnside lobe as the S‐shaped topology on that side of the magnetosheath extends farther downtail. The study demonstrates that the Mars dayside ionosphere exerts significant control over the nightside induced magnetosphere of that planet.Plain Language SummaryMars, which does not have a strong magnetic field, has an induced magnetic environment from the draping of the interplanetary magnetic field from the Sun. It folds around Mars, forming two “lobes” of magnetic field behind the planet with a current sheet of electrified gas (plasma) behind it. The current sheet is not directly behind the planet but rather shifted toward the dawn or dusk direction. It is shown here that one factor controlling the location of the current sheet is the dayside ionosphere. At solar maximum, the ionosphere is dense, the magnetic field slips easily by the planet, and the current sheet is shifted toward dawn. At solar minimum, the ionosphere is relatively weak, the magnetic field slippage is slowed down, and the current sheet shifts toward dusk.Key PointsThere is a systematic Y (i.e., dawn‐dusk) asymmetry in the location of the Martian magnetotail current sheet in modified MSE coordinatesThe asymmetry is controlled by ionospheric conditions, shifting to the dawn (‐Y) during solar maximum and to the dusk during solar minimumThe shift found in this study is not a function of crustal fields, which were omitted, or solar wind conditions, which were held constantPeer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/137681/1/jgra53609_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/137681/2/jgra53609.pd

Pickup oxygen ion velocity space and spatial distribution around Mars

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/94939/1/jgra19106.pd

Parallel, Adaptive‐Mesh‐Refinement MHD for Global Space‐Weather Simulations

The first part of this paper reviews some issues representing major computational challenges for global MHD models of the space environment. These issues include mathematical formulation and discretization of the governing equations that ensure the proper jump conditions and propagation speeds, regions of relativistic Alfvén speed, and controlling the divergence of the magnetic field. The second part of the paper concentrates on modern solution methods that have been developed by the aerodynamics, applied mathematics and DoE communities. Such methods have recently begun to be implemented in space‐physics codes, which solve the governing equations for a compressible magnetized plasma. These techniques include high‐resolution upwind schemes, block‐based solution‐adaptive grids and domain decomposition for parallelization. We describe the space physics MHD code developed at the University of Michigan, based on the developments listed above. © 2003 American Institute of PhysicsPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87656/2/807_1.pd

Modeling a space weather event from the Sun to the Earth: CME generation and interplanetary propagation

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/94980/1/jgra17180.pd