Department of Climate and Space Sciences and Engineering in the College of Engineering at the University of Michigan

CLaSP Seminar Series - Dr. Stefano Livi

Date: March 22, 2018
Time: 3:30 pm - 5:00 pm
Location: SRB Auditorium, room 2246

Title: "Solar Wind Measurements on Solar Orbiter: Discovering the Links Between the Solar Wind and the Atmosphere of Our Sun"

Abstract: Hydrogen and Helium constitute more than 99.9% of the solar wind and the plasma processes governing and ruling the solar wind plasma are by far dominated by those two species. Consequently ions other than protons and alphas, the so-called “heavy ions”, are also often referred to as “minor ions”: they do not affect the dynamics of the system, but act as co-participants in the flow. Exactly here lies their importance: like leaves in the river, they do not affect the flow, but are powerful indicator and tracers of the physical phenomena that acted or still act on the plasma. First and foremost, the charge state of the heavy ions is established very low in the corona, and does not change during propagation: heavy ions carry the imprint of the electron temperature in the region the plasma detached from the Sun. Also, the easiness of ionization (known as First Ionization Potential) affects how long the particles were subject to the gravitational potential of the Sun, before been accelerated by electromagnetic forces, which sets powerful constraints on the dynamic of the early solar wind accelerations. The characteristics of the distribution functions of the ions reveal also the plasma processes that are at work during the expansion: heavy ions travel faster than protons, up to the Alfven speed; the temperature is proportional to the mass of the ion; and present a large anisotropy, clear marker of the conservation of magnetic moment. All plasma characteristics of the heavy ions are moderated by Coulomb collisions and enhanced by wave-particle interaction, making these ions an excellent laboratory for studying the processes that regulates solar wind acceleration and expansion.

Biography: Dr. Stefano Livi has over 30 years experience working on all aspects of the development of instruments for scientific missions, from the conceptual design phase, to the final scientific analysis of the collected data. His range of expertise encompasses plasma analyzers, UV coronographs, mass spectrometers, and energetic particle sensors. He acted as leading Co-Investigator on a number of American, European, Russian, and Japanese missions, including Phobos, Polar, Cassini, SOHO, Rosetta, and Geotail, and received numerous NASA Group Achievement Awards. Presently he is Principal Investigator of the sensor Strofio, to be flown on the BepiColombo mission to Mercury, and of the sensor HIS to be flown on the Solar Orbiter mission. As principal scientist at the Max Planck Institut für Aeronomie (1992-2000), Dr. Livi directed and managed the day-to-day activities of a group composed of approximately 25 scientists and engineers. From March 2004 to October 2006, Dr. Livi served as the Instrument Science Coordinator and Chair of the Instrument Development Program at the Johns Hopkins University Applied Physics Laboratory. 

Upcoming Events

March 27th
3:00 pm - 4:00 pm
CLaSP Special Seminar - Dr. Tom Hamill
March 29th
3:30 pm - 5:00 pm
CLaSP Seminar Series - Dr. Juan Lora
April 4th
3:30 pm - 4:30 pm
CLaSP Special Seminar - Dr. Brian McDonald
April 5th
3:30 pm - 5:00 pm
CLaSP Seminar Series - Prof. Christine Chiu
More Events