Magnetosphere Seminars

2014 - Spring Schedule

Feb 04, 2014 – “Cassini Langmuir Probe observations in Saturn’s magnetosphere”

Speaker:   Michiko Morooka (LASP)
Date & Time:   Feb 4, 2014 ,  4:00 PM Location: LASP Space Science Building, room N248 upstairs. Map
Abstract:  

Cassini Langmuir probe was designed to measure the cold plasma properties. Analyzing its sweep current curve makes possible to estimate the densities of ions and electrons, ion speed, as well as the electron thermal energies independently. In addition, LP can estimate the electron densities of very thin plasma. As a result, LP can provide the… Read more »

Feb 18, 2014 – “Formation of large-scale magnetic flux tubes in turbulence and turbulent convection: theory and numerical simulations”

Speaker:   Igor Rogachevskii (Ben-Gurion University of the Negev, Israel)
Date & Time:   Feb 18, 2014 ,  4:00 PM Location: LASP Space Science Building, room N248 upstairs. Map
Abstract:  

We present a review of theoretical results and detailed numerical simulations related to formation of large-scale magnetic flux tubes in turbulent flows. A suppression of total turbulent pressure by a large-scale (mean) magnetic field is one of the main reasons for formation of large-scale inhomogeneous magnetic structures in stratified turbulence. This effect mimics a negative… Read more »

Mar 4, 2014 – “Review of global simulations studies of the effect of ionospheric outflow on magnetotail dynamics”

Speaker:   Michael Wiltberger (NCAR/HAO)
Date & Time:   Mar 4, 2014 ,  4:00 PM Location: LASP Space Science Building, room N248 upstairs. Map
Abstract:  

Since the detection of O+ ions by satellites in the 1970s it has been known that the ionosphere is an important source of plasma in the Earth’s magnetotail. More recent observations from have shown that these ions can become a dominant component of the plasma in the plasmasheet. Early work in substorm research considered a… Read more »

Apr 1, 2014 – “Nonlinear Electric fields and Dipolarization Fronts in the Inner Magnetosphere”

Speaker:   David Malaspina (LASP)
Date & Time:   Apr 1, 2014 ,  4:00 PM Location: LASP Space Science Building, room N248 upstairs. Map
Abstract:  

Van Allen Probes observations are presented which demonstrate that dipolarization fronts penetrating Earthward of geosynchronous orbit lead to 1) localized enhancements of 1-30 keV electron fluxes and 2) formation of nonlinear electric field structures at the radial distances where wave-particle interactions drive outer radiation belt energization. Nonlinear electric field structures include nonlinear chorus, double layers,… Read more »

Apr 8, 2014 – “Kinetic Simulations of Current Sheets for Different Stellar Magnetospheres”

Speaker:   Carrie Black (Goddard)
Date & Time:   Apr 8, 2014 ,  4:00 PM Location: LASP Space Science Building, room N248 upstairs. Map
Abstract:  

Current sheets are ubiquitous features in stellar atmospheres and exist across kinetic and MHD regimes. In the solar corona, the kinetic scales are far removed from the MHD scales, however, kinetic scale dynamics are believed to be important in diffusion regions where magnetic reconnection occurs. In pulsar magnetospheres, where relativistic pair plasmas exist, these scales… Read more »

Apr 15, 2014 – “The Role of Magnetosheath Plasma Beta in the Formation of Alfven Wings and the Saturation of the Region 1 Field-Aligned Current System”

Speaker:   Frederick Wilder (LASP)
Date & Time:   Apr 15, 2014 ,  4:00 PM Location: LASP Space Science Building, room N248 upstairs. Map
Abstract:  

The phenomena of cross-polar cap potential (CPCP) and ionospheric field-aligned current (FAC) saturation remains largely unexplained. In recent years, empirical observations and statistical studies have been consistent with the Alfven Wing model. In this hypothesis the electric field of the solar wind MHD generator is partially reflected from the ionosphere due to a mismatch in… Read more »

Apr 29, 2014 – “Evolution of relativistic outer belt electrons during an extended quiescent period”

Speaker:   Allison Jaynes (LASP)
Date & Time:   Apr 29, 2014 ,  4:00 PM Location: LASP Space Science Building, room N248 upstairs. Map
Abstract:  

To effectively study loss due to precipitation of relativistic electrons in the radiation belt, it is necessary to isolate this loss by studying a time of relatively quiet geomagnetic activity. We present a case of initial enhancement and slow decay of 700 keV – 2 MeV electron populations in the outer radiation belt during an… Read more »

May 20, 2014 – “The JAXA EXCEED Mission”

Speaker:   Andrew Steffl (SwRI)
Date & Time:   May 20, 2014 ,  4:00 PM Location: LASP Space Science Building, room N248 upstairs.
Abstract:  

JAXA’s Hisaki mission (SPRINT-A) was successfully launched into Earth orbit on 14 September 2013. The sole science instrument on Hisaki is EXCEED, an EUV spectrograph covering the wavelength range 520-1480Å at 3-5Å resolution. EXCEED has two main scientific goals: to estimate the rate of atmospheric loss from terrestrial planets and to study the dynamics of… Read more »