Physics Department Seminar University of Alaska Fairbanks


J O U R N A L    C L U B

 

3 Capstone Talks

Talk 1: Viability of Local Dyson Sphere

Talk 2: Investigating Field Line Resonances in the Jovian Plasma Sheet: Juno Mission and Simulation Data Analysis with Continuous Wavelet and Hilbert-Huang Transforms

Talk 3: Exploring the Efficacy of Unsupervised Feature Extraction for the Identification of Mesoscale Auroral Morphologies

 
by
 
Michael Romero, Vivian Palmer, Aedan McKee
Physics Dept., UAF


 


ABSTRACT

 Talk 1
Title: Viability of Local Dyson Sphere
Speaker: Michael Romero (Physics Dept., UAF)
Abstract
The purpose of this research is to determine the viability of a Dyson mega-structure (sphere) for the purposes of large-scale energy accumulation and dispersal. The large amounts of energy coming from the sun would allow for a massive decrease in fossil fuel dependence and large-scale advancements such as interplanetary and interstellar travel. The simulation models the solar system with 8 planets and the Sun and uses the mass of Mars 6.410 x 10^23 kg as the reference material to build the sphere. The sphere is simulated between 10 Earth years at radii between 1.00 AU and 1.35 AU and it was found that the energy necessary to maintain the structure's position, relative to the Sun, is between 1.7077 x 10^34 J and 3.6297 x 10^34 J; energy demands increasing with a smaller radius for the trade-off of needing much more compact and efficient solar satellites. The net energy collected, with a solar conversion efficiency of 30% for solar panels, is between 3.6937 x 10^33 J and 1.2092 x 10^34 J between 1.20 and 1.35 AU. With our predicted outputs for energy exceeding 10^8 times 2024's current global energy production, the main factor in determining the viability of the model lies in an efficient design of thrusters and solar panels, as well as a reliable and compact method of energy transfer from the sphere.

Talk 2
Title: Investigating Field Line Resonances in the Jovian Plasma Sheet: Juno Mission and Simulation Data Analysis with Continuous Wavelet and Hilbert-Huang Transforms
Speaker: Vivian Palmer (Physics Dept., UAF)
Abstract
Magnetometer observations from the Galileo mission have provided evidence of standing Alfvén waves, also known as Field Line Resonances (FLRs) in the Jovian magnetosphere (e.g., Manners & Masters, 2019). Using primarily Juno magnetometer observations, this project expands on the Galilean findings to identify FLRs in the Jovian current sheet. These waves are a common feature of Earth’s magnetosphere and are thought to be correlated with mono-energetic electron energization that drives some terrestrial discrete auroral arcs. Periodic auroral emissions at Jupiter have also been observed using the Hubble Space Telescope (e.g., Nichols et al., 2017), suggesting these waves participate in generating some auroral emissions at Jupiter as well. We find and characterize short-periodic waves within Jupiter’s equatorial plasma sheet using Continuous Wavelet Transformations (CWT) and Hilbert-Huang Transforms (HHT).  We analyze both the toroidal and poloidal polarizations of the perturbed transverse magnetic field where the Juno spacecraft crosses or skims Jupiter’s equatorial plasma sheet. The same analysis tools are applied to fluctuations of the observed density moments to help distinguish Alfvénic modes from structure-driven modes. We also analyze magnetic field perturbations derived from FLR simulations to better elucidate the harmonic structure found within the Juno data. Preliminary results suggest the presence of FLRs with periods in the range of some tens of minutes or less, comparable to previous findings.

Talk 3
Title: Exploring the Efficacy of Unsupervised Feature Extraction for the Identification of Mesoscale Auroral Morphologies
Speaker: Aedan McKee (Physics Dept., UAF)
Abstract
THEMIS ASI database  contains an expanding collection of billions of images, however it lacks efficient methods for retrieving specific mesoscale phenomena, such as auroral beads. This research explores the use of an unsupervised machine learning model to vectorize images through a feature extraction process enabling the use of distances between vectors for event searching. By using FAISS and its FlatIP index method, we ensure the identification of the closest feature vectors by the inner product comparison. This approach allows for statistical analysis on a wide range of events that would not have been possible before. Setting the stage for studying sub-storms and onset waves and geomagnetic relationships with auroral morphologies such as auroral beads. Preliminary performance of the algorithm has shown great results in identifying events but with false positives, with additional work and refinement this can be a potent tool to auroral physics.







 


Friday, 01 May 2026


    Note: Hybrid in Globe room and by zoom:
https://zoom.us/j/796501820?pwd=R2xEcXNwZGVRbG0va29iN2REU241UT09





3:45PM