Magnetosphere Seminars

2015 - Spring Schedule

Jan 27, 2015 – “Source and seed populations for relativistic electrons: Their roles in radiation belt changes”

Speaker:   Dan Baker and Allison Jaynes (LASP)
Date & Time:   Jan 27, 2015 ,  4:00 PM Location: LASP Space Science Building, room W120 (1st floor).
Abstract:  

Early studies of Van Allen belt relativistic electrons showed a strong relationship between outer zone electron flux levels and solar wind speed. Examination of this relationship later was extended to show more broadly that various kinds of enhanced geomagnetic activity often cause powerful radiation belt flux increases. Such enhancements have been shown to have a… Read more »

Feb 17, 2015 – “Fun physics at Martian crustal fields”

Speaker:   Dave Brain (LASP)
Date & Time:   Feb 17, 2015 ,  4:00 PM Location: LASP Space Science Building, room N100 (1st floor).
Abstract:  

While Mars is typically classified as an unmagnetized object similar to Venus, Titan, or comets, it possesses regions of strongly magnetized crust. The crustal magnetic fields are sufficiently strong that they participate in the Martian interaction with its near-space environment, enabling a number of processes typically associated with intrinsic magnetospheres. I’ll present some recent results… Read more »

Mar 03, 2015 – “Using Comets as Solar Probes”

Speaker:   Paul Bryans (UCAR)
Date & Time:   Mar 03, 2015 ,  4:00 PM Location: LASP Space Science Building, room N100 (1st floor).
Abstract:  

The EUV emission resulting from comets’ passage through the solar atmosphere has opened many exciting avenues of study. The observations show the sublimated cometary material to interact with ambient magnetic field and highlight magnetic features that are not normally visible with EUV telescopes. In this talk, I will outline a model that describes the interaction… Read more »

Mar 31, 2015 – “Reproducing dust-induced antenna signals at LASP’s IMPACT accelerator”

Speaker:   Andrew Collette (LASP)
Date & Time:   Mar 31, 2015 ,  4:00 PM Location: LASP Space Science Building, room N100 (1st floor).
Abstract:  

We describe laboratory experiments which reproduce characteristic signals observed on spacecraft, believed to be caused by dust impact.  A simulated spacecraft, including an antenna system using a facsimile of the preamplifier electronics from the STEREO/WAVES instrument, was bombarded by 10 km/s submicron-sized dust at the University of Colorado IMPACT dust accelerator facility.  Signal variation was… Read more »

Apr 7, 2015 – “Kinetic Alfven Waves in the Inner Magnetosphere Driven by Interplanetary Shock-Induced Magnetospheric Compression”

Speaker:   David Malaspina (LASP)
Date & Time:   Apr 7, 2015 ,  4:00 PM Location: LASP Space Science Building, room N100 (1st floor).
Abstract:  

An interplanetary shock impacted Earth’s magnetic field on October 2, 2013, compressing the magnetosphere and triggering large-amplitude ULF (ultra low frequency) waves at the location of Van Allen Probe B. At the same time, Van Allen Probe B observed high frequency wave power in conjunction with, and modulated by, this ULF wave. A detailed analysis… Read more »

Apr 14, 2015 – “Global MHD simulations of solar convection and the solar dynamo.”

Speaker:   Jean-Francois Cossette (LASP)
Date & Time:   Apr 14, 2015 ,  4:00 PM Location: LASP Space Science Building, room N100 (1st floor).
Abstract:  

Global MHD simulations of solar convection have recently been able to produce large-scale magnetic fields undergoing polarity reversals about the equator. In this talk I present results from a global MHD convection experiment performed with the EULAG-MHD model, a general-purpose finite volume hydrodynamical code for the simulation of fluids in general, in which solar-like magnetic… Read more »

Apr 28, 2015 – “Solar Wind Turbulent Dissipation: A Collisionless Zoo”

Speaker:   Steven Cranmer (LASP)
Date & Time:   Apr 28, 2015 ,  2:00 PM Location: LASP Space Science Building, room N100 (1st floor).
Abstract:  

Despite many years of study, the basic physical processes responsible for producing the solar wind are not known — or at least not universally agreed upon.  There are many proposed solutions to the intertwined problems of coronal heating, wind acceleration, and particle energization, and the real problem is how to choose between them.  This presentation… Read more »

May 5, 2015 – “High Resolution Global Magnetohydrodynamic Simulation of Bursty Bulk Flows”

Speaker:   Michael Wiltberger (NCAR)
Date & Time:   May 5, 2015 ,  4:00 PM Location: LASP Space Science Building, room N100 (1st floor).
Abstract:  

A high-resolution global magnetohydrodynamic simulation is conducted with the Lyon-Fedder-Mobarry (LFM) model for idealized solar wind conditions.  Within the simulation results high-speed flows are seen throughout the magnetotail when the interplanetary magnetic field (IMF) is southward.  Case study analysis of these flows shows that they have an enhancement in BZ and a decrease in density… Read more »

May 12, 2015 – “Radiation belt electron precipitation response to ULF waves”

Speaker:   Thiago Brito (LASP)
Date & Time:   May 12, 2015 ,  4:00 PM Location: LASP Space Science Building, room N100 (1st floor).
Abstract:  

Balloon-borne instruments, including most recently the BARREL balloon mission, detecting radiation belt precipitation frequently observe oscillations in the mHz frequency range, corresponding to ULF waves. Although ULF waves in the magnetosphere are seldom directly linked to increases in electron precipitation since their oscillation periods are much larger than the gyroperiod and the bounce period of… Read more »