Graduate Student & Post-Doc Seminar

Date: 

Thursday, March 7, 2019, 12:00pm to 1:00pm

Location: 

Haller Hall, Geo Museum 102

"Constraining planetary interiors with magnetic fields"

Speaker: Kimee Moore

Abstract: What is going on below a planet’s surface? Two of the most fundamental aspects of a planet are its interior dynamics and structure, but these properties are surprisingly poorly constrained for most of the Solar System. What’s more, a body’s modern-day structure reflects is past formation and thermal evolution, so constraining planetary interiors can help to better understand the history of the Solar System at large. To address these questions, my research investigates the connection between magnetic fields and planetary interiors. Since actively generated planetary magnetic fields (dynamos) are sensitive to a wide range of properties within the planet, they represent an important dataset that is complementary to other analysis techniques (e.g. seismology or gravity).

In this talk, I will use Jupiter as a case study, and demonstrate how Jupiter’s magnetic field reflects important aspects of both its atmospheric dynamics and deep interior structure. Using innovative mathematical analysis of satellite data (L1 norm/elastic net), I previously discovered that Jupiter’s field has a singular spot of intense, localized magnetic flux—the Great Blue Spot. Now, I report the first definitive detection of time-variation (secular variation) in a dynamo field beyond Earth, and show that we can explain this time-variation physically in terms of Jupiter’s atmosphere acting on the Great Blue Spot. Additionally, the spatial morphology of Jupiter’s magnetic field suggests that Jupiter likely has a dilute core. These results have important implications for the formation of our Solar System, the interior physics of giant planets, and our understanding of our own planet’s magnetic field.

GSPD comprises scientific talks up to one hour in length by graduate students and post docs, but all are welcome to attend, including faculty and staff. Lunch will be provided. As always, please plan to bring reusable plates and cutlery to reduce waste.