University of Minnesota
School of Physics & Astronomy

Physics and Astronomy Calendar

Tuesday, March 21st 2017
12:20 pm:
Speaker: Scott Thaller
Subject: Evidence for modulations of the cold plasma density and convection in the inner magnetosphere being driven at the solar rotation period

"In this talk I will present work we have done with Van Allen Probes data which provides strong evidence for solar rotation modulation of the plasmapause location, dawn-dusk electric field, and cold plasma density from 2.5 < L < 5. In this research we show that the solar rotation modulation of the inner magnetosphere is prominent during the declining phase of the solar cycle when there is a heightened occurrence of fast solar wind streams routinely passing over the earth at the solar rotation period, called Co-rotating Interaction Regions (CIRs). The occurrence of enhanced periods of geomagnetic activity being driven by the CIRs every ~27 days leads to modulation of the plasmasphere on that timescale. In contrast, during solar maximum when the geomagnetic activity in the magnetosphere is more likely to be driven by CMEs, the solar rotation modulation is less prominent, if at all present. I will also present research we have conducted on the cold plasma outflows that occur during geomagnetic activity, including outflows driven at the solar rotation period.

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