Senior Thesis Defense

Monday, May 30, 2016, Wilder 202, 10:00 AM

Kathryn Waychoff​, Department of Physics and Astronomy, Dartmouth College

Title:  Zonal Wind Variability of the Jovian Planets


The proximity and massive scale of Jupiter has made it a uniquely observable case study in planetary atmospheric dynamics, resulting in a wealth of data from several missions. Jupiter’s characteristically striated atmosphere makes it a prime candidate for zonal wind profiles. These plots of longitudinally averaged wind velocities given with respect to latitude give insight to a key component of the east-west motion of the Jovian atmosphere. Zonal winds have been studied in detail from previous Hubble (1990s-2010s), Cassini (2000-2001), and Voyager (1979) imaging. We now add on additional Hubble data points from 2015 and 2016, and contrast current behavior with past behavior. Images from Hubble are pieced together into single-rotation maps and contrast is significantly enhanced. Subsequent rotations are cross-correlated in pairs. By plotting longitudinally averaged winds -50 to 50 degrees versus latitude, we create zonal wind profiles from each date set. We use red wavelengths (631 nm and 658 nm) as a baseline with supplemental data ranging from 275 nm to 889 nm. We find that Jupiter’s zonal winds have remained relatively constant over the past 40 years with minor fluctuations on a sub-seasonal time scale. By comparing images in different wavelengths we discover similar velocity structures at different altitudes, but higher variability in wavelengths both significantly longer and shorter than the baseline reds. Additionally we show that the same processes that have been applied to analyze Jupiter’s zonal wind velocities can be applied to Neptune and Uranus, with some difficulty.