Michael Wiltberger

Efficiency of Electromagnetic Energy Transfer from Solar Wind to Ionosphere through Magnetospheric Ultra-Low Frequency Waves

whawkins — Wed, 13 Aug 2025 20:10:55 +0000

Efficiency of Electromagnetic Energy Transfer from Solar Wind to Ionosphere through Magnetospheric Ultra-Low Frequency Waves whawkins Wed, 08/13/2025 - 14:10

Author:

whawkins

Aug 13, 2025

(a) 5-200 s bandpassed $S_{A//}$ mapped to the ionospheric altitude and averaged over the four-hour interval. (b) 5-200s bandpassed $S_{A//}$ in the 7 MLT plane. (c) 4.5-5.5 mHz root-integrated power (RIP) of radial electric field $E_r$ in the equatorial plane. (d) 4.5-5.5 mHz RIP of azimuthal magnetic field $B_\phi$ in the meridional plane of 7 MLT. (e-f) Field-aligned keograms of $E_{mrd}$ and $B_\phi$ along the green field line with the largest $S_{A//}$. The green curve in (b) and (d) is a magnetic field line in the 7 MLT plane connecting to the green cross in (a) which marks the location with the peak $S_{A//}$. This field line crosses the equatorial plane at the green cross in (c).

Geophysical Research Letter: Scientists have long been interested in how energy from the Sun is transferred into Earth’s space environment. The Earth's magnetosphere is an important intermediate environment between the solar wind and the upper atmosphere. Consisting of plasma and magnetic field, the magnetosphere is full of intrinsic plasma waves that are capable of energy transport, particularly a group in the frequency range of a few to a few tens Millihertz that are especially efficient in connecting the magnetosphere and the ionosphere. However, due to the global presence and propagation features of those waves, it has been very challenging with measurements from a limited number of locations to understand the efficiency of the wave based energy transfer mechanism. This study uses a first-principles computational model that can resolve the fundamental physics related to the low frequency plasma waves, to carry out idealized numerical experiments to investigate the electromagnetic energy flow in response to undulating solar wind. The theoretical study provides new understanding of the significance of the electromagnetic energy flow and its dependence on different parameters.

Multifluid equations for MHD

whawkins — Fri, 23 May 2025 15:19:59 +0000

Multifluid equations for MHD whawkins Fri, 05/23/2025 - 09:19

Author:

whawkins

May 23, 2025

JGR Space Physics: The ionized atoms in near-Earth space, the plasma, consist of a number of species including hydrogen, helium, and oxygen in various states of ionization. Hydrogen is usually the predominant component, but other species can play an important role in the dynamics of space plasmas. Computer simulations of these plasmas, including the effects of the magnetic and electric fields, have been quite successful at describing the near-Earth space. However, in general, they have rarely included any ion species other than hydrogen. This paper describes a multifluid approach that makes it possible to include other ion species assuming the ions are tightly bound to magnetic field lines. In this case, the ions all move together perpendicular to the local magnetic field but are free to move individually along the field direction. This work shows how changes in the magnetic field direction can act to accelerate ions along the field, much like a jai alai ball being thrown with a cesta. The work also shows how plasma waves behave in such a multifluid environment. Finally, the paper presents results of a super-computer simulation of the near-Earth space, modeling the behavior of different plasma fluids and their interactions during a geomagnetic storm.

Overview image of the multifluid MAGE application with a separate fluid for plasma of plasmaspheric origin. All panels are shown in the equatorial plane of the magnetosphere and panels (b-e) correspond to the marked box in panel (a). Shown are: the residual, i.e., non-dipolar component, of the northward magnetic field (a); the density and temperature of fluid~1 (b and c); and the density and temperature of fluid~2 (d and e).

International UCoMP Users Workshop

whawkins — Thu, 07 Sep 2023 19:23:33 +0000

International UCoMP Users Workshop whawkins Thu, 09/07/2023 - 13:23

Author:

whawkins

Sep 7, 2023

Steve displaying slides at UCoMP users workshop.

HAO director Holly Gilbert comments: "There was great energy around the UCoMP Users Workshop last week, with many visitors coming from around the world to participate. Thanks to those who made it a success, including many early career folks!"

The first-ever UCoMP Data User’s Workshop was held the week of August 29 and was a great success. The purpose was to introduce UCoMP to the community and to organize working groups to collaborate on UCoMP first results to be published in a topical issue of Solar Physics. The workshop combined tutorial-type presentations from the UCoMP team, discussions between the UCoMP team and users, user presentations, and hands-on activities for attendees. There were 41 attendees: 23 in-person and 18 remote. Recordings of the presentations can be found on the UCoMP Youtube channel.

Cloudnative OpenScienceLabs: Effectively sharing HPC results and knowledge

whawkins — Thu, 18 May 2023 16:40:52 +0000

Cloudnative OpenScienceLabs: Effectively sharing HPC results and knowledge whawkins Thu, 05/18/2023 - 10:40

Author:

whawkins

May 18, 2023

ACM Trans. Graph: We present a method for publishing and sharing high performance compute (HPC) code and results in a ready-to-use interactive environment with the explicit goal to lower the entrance barrier to HPC. We call such an environment an OpenScienceLab (OSL) and have prototypically evaluated usability, scalability and portability on the Multiscale Atmosphere Geospace Environment as a Fortran/Python based, massively parallel HPC codebase. Six use-cases, from PeerReview-Companions to SummerSchools were used to test the OSL design, finding that the functional method itself improves the utility of the codebase: For a senior code-owner, the OSLs offer more scalable knowledge-distribution than in-person onboarding and for an end-user, the OSLs achieve removal of all compilation and dependency management, saving the end-user time and enabling first timers to quickly try out working with an HPC-application both locally as well as on large machines. This is achieved by leveraging cloud-native methods and DevSecOps such as containerization, orchestration and automation as well as security best practices.

Example Notebook from [Sorathia et al. 2022] that shows a tutorial for MAGE/GAMERA [Sorathia et al. 2020]. It also shows on the left side of the screen, how the group-shares allow users to share their plots and data if their users have the Access Control Lists ACL set for IDP-group-members of jupyter_research_pokeball_student. The data-set loaded into this OSL running in Vienna, AT stems from NCAR, USA, via Globus. The run-time and codebase is accessible to anyone in this IAM-group, optional membership in the additional aocc_admin IDP-group allows admin rights to the whole application. In the inlay (right), the 3D rendering produced by the paraview-kernel is shown.

The contribution of plasma sheet bubbles to stormtime ring current buildup and evolution of the energy composition

whawkins — Thu, 18 May 2023 16:28:08 +0000

The contribution of plasma sheet bubbles to stormtime ring current buildup and evolution of the energy composition whawkins Thu, 05/18/2023 - 10:28

Author:

whawkins

May 18, 2023

JGR Space Physics: The formation of the ring current is one of the defining features of the near-Earth space response to solar storms. While it is known that the ring current originates from Earth’s magnetic tail, the relative roles of different transport mechanisms remains unclear. In this study, we utilize numerical modeling to investigate ring current buildup for a specific solar storm, and find that flows that are medium scale relative to the system size and referred to as plasma “bubbles”, are responsible for at least half of the total buildup of ring current plasma. Our analysis also shows that the bubbles displace some of the background plasma on their way Earthward, which is important when calculating their net contribution to the ring current. The modeled ring current energy spectrum is in good agreement with spacecraft observations, and the evolution of the energy spectrum is driven by both an evolving plasma population in the tail and by energy-dependent charge exchange. The ability to accurately model the complex interactions between the ring current and Earth’s geospace system is critical for understanding the full impacts of solar storms.

Comparison of proton intensities between (a) RBSPICE and (b) RCM for the full energy spectra between 10 and 200 keV. (c) Comparison between the Observed Sym-H (blue), that calculated from the simulation (orange), and the DPS-Dst evaluated in the model within 6 RE (green), the same as in Figure 1. (d) RCM pressure and RBSP-B's full trajectory (orange line) and current position (white circle with orange border) mapped along field lines to the equatorial plane. The vertical lines in panels (a), (b), and (c), and pressure and spacecraft location in panel (d), all correspond to the time indicated in panel (d). The thin colored bar below panel (b) shows the RCM pressure at the spacecraft location for a given time, with the same colorbar as panel (d).

Thermospheric Density Perturbations Produced by Traveling Atmospheric Disturbances during August 2005 Storm

whawkins — Fri, 16 Dec 2022 19:44:31 +0000

Thermospheric Density Perturbations Produced by Traveling Atmospheric Disturbances during August 2005 Storm whawkins Fri, 12/16/2022 - 12:44

Author:

whawkins

Dec 16, 2022

During geomagnetic storms, increased activity within the geospace environment causes large scale plasma convection to occur and electrons to precipitate into the upper atmosphere. The enhanced heating of the thermosphere by the plasma convection and electron precipitation can produce large perturbations in the neutral density. These neutral density perturbations propagate away from their point of origin, oftentimes traveling to the equator and into the other hemisphere. Here, simulation results using a high resolution coupled geospace model that includes a magnetosphere, inner magnetosphere, ionosphere, and thermosphere model show that neutral density perturbations generated in one hemisphere can propagate far enough to interact with those in the other hemisphere. The intersection of two or more perturbations produce regions of larger neutral density perturbations. The high resolution coupled geospace model performs significantly better than the standalone model when compared to observations of neutral density by low altitude spacecraft. A significant fraction of the observed neutral density perturbations is captured by the coupled model, especially those at low latitudes. Proper simulation and understanding of storm-time neutral density perturbations is imperative to space weather prediction as neutral density perturbations can greatly affect satellite drag.

Snapshots that follow the neutral density perturbation observed by CHAMP (star) and GRACE (circle) at low latitude at 13:20 UT. The approximate location of the wavefront for TADs that intersect near CHAMP’s position at 13:20 UT are indicated by a line white line for the northern hemisphere and black line for the southern hemisphere.

2022 Space Weather Summer School

whawkins — Tue, 30 Aug 2022 15:45:48 +0000

2022 Space Weather Summer School whawkins Tue, 08/30/2022 - 09:45

Author:

whawkins

Aug 30, 2022

FYI, we will not be holding a Space Weather Summer School in 2023. We hope to resume in 2024.

HAO held the latest in a series of successful Space Weather Summer Schools in Boulder, Colorado during the last 2 weeks of July. This unique educational workshop brought together 31 students mainly from the United States along with two students from abroad. Lecturers included experts in solar physics, solar wind, magnetsophere, and ionosphere-thermosphere in order to provide the students with a comprehensive background of the complete space weather system. In addition to lectures on the physics of the system, students learned from experts at the Space Weather Prediction Center about the challenges in making accurate space weather forecasts. Specialists provided an understanding of how space weather processes turn into impacts in human systems such as the power grid. Each day of the school included a computer-based laboratory exercise that let the students get hands-on experience with the models used to simulate space weather. HAO was pleased to once again provide students with an informative, comprehensive, and well well-appreciated introduction to space weather.

SWSS 2022 Group Photograph

The Multiscale Atmosphere-Geospace Environment (MAGE) model

kolinski — Mon, 11 Jul 2022 21:20:33 +0000

The Multiscale Atmosphere-Geospace Environment (MAGE) model kolinski Mon, 07/11/2022 - 15:20

Michael Wiltberger

Efficiency of Electromagnetic Energy Transfer from Solar Wind to Ionosphere through Magnetospheric Ultra-Low Frequency Waves

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Multifluid equations for MHD

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International UCoMP Users Workshop

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Cloudnative OpenScienceLabs: Effectively sharing HPC results and knowledge

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The contribution of plasma sheet bubbles to stormtime ring current buildup and evolution of the energy composition

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Thermospheric Density Perturbations Produced by Traveling Atmospheric Disturbances during August 2005 Storm

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2022 Space Weather Summer School

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The Multiscale Atmosphere-Geospace Environment (MAGE) model

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