Space Physics Seminar

semester, 2019


Tuesday, January 22nd 2019
1:25 pm:
Space Physics Seminar in Tate 301-20
Organizational Meeting

Tuesday, January 29th 2019
1:25 pm:
Space Physics Seminar in Tate 301-20
There will be no seminar this week.

Tuesday, February 5th 2019
1:25 pm:
Space Physics Seminar in Tate 301-20
To be announced

Tuesday, February 12th 2019
1:25 pm:
Space Physics Seminar in Tate 301-20
Speaker: Peter Bruggeman, Mechanical Engineering, UMN
Subject: Physics of Low Temperature Plasmas: a Unique Non-Equilibrium State for Tackling Grand Societal Challenges

Tuesday, February 19th 2019
1:25 pm:
Space Physics Seminar in Tate 301-20
Speaker: Cynthia Cattell and Chris Colpitts
Subject: Wave generation by relativistic electron beams in a plasma: Initial results fromLAPD run

Tuesday, February 26th 2019
1:25 pm:
Space Physics Seminar in Tate 301-20
Speaker: Y. Miyoshi (Nagoya University, Project Scientist of ERG/Arase mission) and Y. Kasahara (Kanazawa University)
Subject: 1. Overview of Arase and highlights from the prime mission. 2. Highlights from plasma wave observation by Arase

These are two talks on the Japanese radiation belt mission, ARASE.


Tuesday, March 5th 2019
1:25 pm:
Space Physics Seminar in Tate 301-20
Speaker: Demoz Gebre Egziabher, Aerospace Engineering, UMN
Subject: Signal of Opportunity Navigation in Deep. Space

Tuesday, March 12th 2019
1:25 pm:
Space Physics Seminar in Tate 301-20
Speaker: Aaron Breneman
Subject: The mysterious post-noon global scale coherence in balloon precipitation signatures

Tuesday, March 26th 2019
1:25 pm:
Space Physics Seminar in Tate 301-20
Speaker: Trevor Knuth
Subject: Fast time variations in solar flare X-ray flux - A probe for particle acceleration

Tuesday, April 2nd 2019
1:25 pm:
Space Physics Seminar in Tate 301-20
Speaker: Sophie Musset
Subject: Energetic electrons in connection with solar coronal jets

Flare-associated coronal EUV jets outline open magnetic field lines providing an escaping path to the interplanetary medium for particles accelerated during solar flares. Several studies have shown an observational link between coronal jets (observed in EUV or soft X-rays) and type III radio bursts, produced by escaping beams of energetic electrons, or in-situ energetic electron events. In a few events, coronal jets have also been associated with X-ray emitting energetic electrons during flares. However, the likelihood of the association of energetic electrons to coronal jets as well as the link between jet properties and electron properties has not been investigated on a large sample of events.

I will present a statistical study of the link between X-ray producing energetic electrons observed with RHESSI and the associated coronal EUV jets by looking at their relative timing, as well as their spatial and spectral characteristics. We found non-thermal X-ray emission in only 1/4 of our events, which were not necessarily the most energetic flares or jets. I will discuss the statistical distribution of properties of jets and associated flares in the context of jet modelling.


Tuesday, April 9th 2019
1:25 pm:
Space Physics Seminar in Tate 301-20
To be announced.

Tuesday, April 16th 2019
1:25 pm:
Space Physics Seminar in 5th floor Walter Library
Subject: MSI Poster session Physical Sciences 2:15-3

Tuesday, April 23rd 2019
1:25 pm:
Space Physics Seminar in Tate 301-20
Speaker: Sheng Tian
Subject: The azimuthal propagation of dipolarization in the inner-magnetosphere

Tuesday, April 30th 2019
1:25 pm:
Space Physics Seminar in Tate 301-20
To be announced.

Tuesday, May 7th 2019
1:25 pm:
Space Physics Seminar in Tate 301-20
Speaker: Prof. Mark Engebretson
Subject: MMS, Van Allen Probes, GOES 13, and Ground Based Magnetometer Observations of EMIC Wave Events Before, During, and After a Modest Interplanetary Shock

Friday, May 10th 2019
3:00 pm:
Space Physics Seminar in Tate 301-20
Speaker: Pof. John Sample, Montana State University
Subject: Relativistic Electron Precipitation: Observations from Balloons and CubeSats
NOTE SPECIAL TIME
3:00 pm:
Space Physics Seminar in Physics Tate 301-20
Speaker: John Sample, Montana State University.
Subject: Relativistic Electron Precipitation: Observations from Balloons and CubeSats
Faculty Host: Aaron Breneman

Tuesday, May 14th 2019
1:25 pm:
Space Physics Seminar in Tate 301-20
There will be no seminar this week.

Tuesday, September 3rd 2019
1:25 pm:
Space Physics Seminar in Tate 201-20
There will be no seminar this week.

Tuesday, September 10th 2019
1:25 pm:
Space Physics Seminar in Tate 201-20
Organizational Meeting

Tuesday, September 17th 2019
1:25 pm:
Space Physics Seminar in Tate 201-20
Speaker: no seminar this week
To be announced.

Tuesday, September 24th 2019
1:25 pm:
Space Physics Seminar in Tate 201-20
Speaker: Aaron Breneman
Subject: Outer belt electron loss driven by solar wind density structures

Tuesday, October 1st 2019
1:25 pm:
Space Physics Seminar in Tate 201-20
Journal club - Article "Magnetohydrodynamic waves and coronal seismology: an overview of recent results"

Tuesday, October 8th 2019
1:25 pm:
Space Physics Seminar in Tate 201-20
There will be no seminar this week.

Tuesday, October 15th 2019
1:25 pm:
Space Physics Seminar in Tate 201-20
Speaker: Sheng Tian
Subject: Observations on MHD-scale properties of dipolarization in the earth's magnetosphere during geomagnetic storms"

Tuesday, October 22nd 2019
1:25 pm:
Space Physics Seminar in Tate 201-20
Speaker: Trevor Knuth
Subject: Current Status of the UMN SmallSat Research Lab

Tuesday, October 29th 2019
1:25 pm:
Space Physics Seminar in Tate 201-20
Speaker: no seminar this week-seminar cancelled. rescheduled for Nov.19

Tuesday, November 5th 2019
1:25 pm:
Space Physics Seminar in Tate 201-20
Speaker: Aaron West
Subject: "Numerical Studies of Kinetic Field Line Resonances"

Field Line Resonances (FLRs) form as eigenmodes of Alfvén waves between conductive ionospheric boundaries along geomagnetic field lines. When kinetic Alfvén waves develop along FLRs, electron inertial effects can limit the width of the structure, leading to dispersive wave trains, stronger parallel electric fields, and particle acceleration. Kinetic field line resonances (KFLRs) have been detected by the Van Allen Probes in conjunction with steep density gradients, but their evolution and dynamics have been insufficiently modeled.
A numerical 3D time-domain model explores the structure of FLRs in an idealized two-fluid dipole scheme. A finite conductivity current sheet ionospheric boundary condition allows for Hall coupling between the shear Alfvén and fast mode waves. This coupling can mode convert fast waves driven by dipolarization flows into Alfvén waves, feeding FLR wave amplitudes. Gradients in Alfven speed can induce phase mixing between shear Alfven and slow mode waves, reducing the coherent perpendicular FLR wavelengths. Once wavelengths become comparable to electron inertial length scales, FLRs begin to exhibit kinetic effects, and require Debye scale resolution. The model provides the framework for future investigations of kinetic plasma wave evolution dynamics.


Tuesday, November 12th 2019
1:25 pm:
Space Physics Seminar in Tate 201-20
Speaker: Slava Pilipenko
Subject: ULF-ELF response of the upper ionosphere to electromagnetic atmospheric and industrial activities

Tuesday, November 19th 2019
1:25 pm:
Space Physics Seminar in Tate 201-20
Speaker: Cynthia Cattell and Lindsay Glesener
Subject: Periodicities in Type III radio bursts observed by Parker Solar Probe and in coronal active regions

Periodicities have frequently been reported across many wavelengths in the solar corona. We focus on coordinated observations of Type III radio busts from the Fields instrument on Parker Solar Probe, of EUV emissions in the 211A and 171A bands by the SDO/AIA, and of solar flare x-rays by Nuclear Spectroscopic Telescope Array (NuSTAR) on April 12, 2019. Periodicities of ~ 5 minutes in the EUV in several areas of an active region are well correlated with the repetition rate of the Type III radio bursts. Detrended 211A light curves show periodic sawtooth profiles in one area, with rapid drops occurring slightly after the onset of the radio bursts. In this area, the detrended light curves for the 171A band show similar periodicity, with peaks lagging those seen in 211A. This is suggestive of rapid and impulsive cooling. NuSTAR x-rays provide evidence for a flare during the interval of Type III bursts but there is not a one to one correspondence between the x-rays and Type III bursts. Observations are somewhat consistent with previous studies showing correlated periodicities in 211A and Type II bursts, although periods are longer. Five minute periods have frequently been reported in sunspots


Tuesday, November 26th 2019
1:25 pm:
Space Physics Seminar in Tate 201-20
Speaker: No seminar this week

Tuesday, December 3rd 2019
1:25 pm:
Space Physics Seminar in Tate 201-20
Speaker: AGU Practice Talks

Tuesday, December 10th 2019
1:25 pm:
Space Physics Seminar in Tate 201-20
To be announced

The weekly calendar is also available via subscription to the physics-announce mailing list, and by RSS feed.