Physics and Astronomy Space Plasma Seminar - Endawoke Yizengaw, Boston College

"Multi-Instruments Observations to Mitigate Space Weather Impacts on Our Technological Systems"

March 31, 2015
4 pm - 5 pm
Location
Wilder 111
Sponsored by
Physics & Astronomy Department
Audience
Public
More information
Tressena Manning
603-646-2854

Abstract: The global density structure of the inner-magnetosphere can significantly influence the propagation of radio waves, causing range errors, and rapid phase and amplitude fluctuations (radio scintillation) of satellite signals that may lead to degradation of the system performance and its accuracy and reliability. In order to measure, forecast, understand, and mitigate space weather induced impacts on present-day technological systems, understanding of the structure and behavior of the global density structure during different geomagnetic activity periods is essential. The density within the ionosphere and plasmasphere can be monitored using a combination of techniques that use both ground- and space-based instruments. While the dramatically growing number of GPS receivers on the ground and onboard Low-Earth-Orbit (LEO) satellites offers an excellent opportunity for remote sensing and monitoring of the ionospheric and plasmaspheric density structure using tomographic reconstruction technique, pairs of magnetometers observations provide one of the possible dayside driving mechanisms that govern the structure and dynamics of the ionosphere in the low/mid-latitude region. However, the uneven distribution of ground-based instruments in the equatorial regions hinders our ability to obtain a global understanding of the dynamics and structure of the equatorial ionosphere. For example, in Africa, which had been mostly devoid of ground-based instruments until recently, the ionospheric density structure has been traditionally estimated by model interpolation over vast geographic areas, and that make difficult for the communication and navigation systems operating in the region. On the other hand, according to the observations performed at different longitudes, using satellite and recently deployed limited ground-based instruments; both ionospheric density structure and its governing force (the vertical drift velocities) have shown significant longitudinal differences. In this colloquium presentation, the combined diagnostic observations of everything, but the kitchen sink, will be portrayed. These include observations of GPS TEC, TOPEX and JASON altimeter TEC, IMAGE EUV and FUV, GUVI (composition change), Magnetometer (equatorial electrojet and ULF wave signatures), and many other datasets from multi-instruments onboard LEO satellites such as DMSP, COSMIC, C/NOFS, CHAMP, GRACE, and SWARM.

Location
Wilder 111
Sponsored by
Physics & Astronomy Department
Audience
Public
More information
Tressena Manning
603-646-2854