2015 Senior Thesis Presentations

Helen Hill
Sunday, June 14, 2015

Studying the troposphere's response to stratospheric perturbations, diagnosing apparent seasonal variation in GPS readings, packaging variable-star photometry for  a secondary school setting, exploring controls on Mesozoic to Cenozoic crustal metamorphism and deformation in the southwestern US, surveying asteroids using one of the biggest telescopes in the world, and helping build and then take measurements with WAO's first autonomous telescope: Discover what EAPS class of 2015 has been working on.

Each year, graduating seniors majoring in EAPS present a thesis in completion of their Bachelor of Science Degree. This year we had a class of six students specializing in areas across the earth, atmospheric and planetary sciences.

For her senior thesis, Understanding the Spatial Distribution of the Southern Hemisphere Near-Surface Westerlies and Its TrendsCasey Hilgenbrink worked with Professor of Meteorology R. Alan Plumb.

"In some idealized general circulation models, the troposphere's response to stratospheric perturbations is much stronger and longer-lived than what is observed in reality. Previous work by Chan and Plumb (2009) revealed that such cases are marked by bimodality in the distribution of the latitude of maximum surface zonal-mean zonal winds. The goal of my thesis was to determine if such bimodality exists in the real southern hemisphere (SH) near-surface jet, which would imply the existence of an additional mode of tropospheric variability that is both stronger and longer-lived than what has previously been observed. Using reanalysis data, I ultimately showed that the SH jet is unlikely to exhibit any bimodality; however, along the way, I did find that the dominant mode of zonal wind variability over the South Pacific Ocean is an interesting splitting and "unsplitting" of the jet, rather than a north-south shift around the jet's time-mean position as is conventionally understood. Finally, given that stratospheric ozone depletion has been shown to have an impact on the SH surface circulation in austral summer, I also examined how the spatial distribution of the SH near-surface westerlies are changing with time. In agreement with previous work, I found that the SH jet has undergone a 1-2 degree poleward shift in southern summer from the pre-ozone-hole to ozone-hole eras. Furthermore, I found the suggestion of a poleward jet shift in May, a novel result which seems to be consistent with a secondary maximum in ozone depletion near the tropopause in late fall that has been demonstrated by other authors (Thompson et al. 2011)." 

Casey is going on to pursue a Ph.D. in Atmospheric Sciences at the University of Washington. 

For her senior thesis, Ice and the Apparent Seasonal Variation of GPS Positions for AlaskaKelly Kochanski worked with Professor of Geophysis Thomas Herring.

"Many GPS stations show non-tectonic seasonal movement due to seasonal changes in atmospheric pressure, tidal forces, and crustal loading due to snowfall. Although these motions are usually consistent between neighboring stations, we found several stations in western Alaska that appear to move out of phase with the motion of the rest of the state and rise upwards by several centimeters each winter. After detailed analysis of the position time-series of these stations and the local weather conditions, we concluded that these apparent motions are caused by ice accumulating on the station and delaying the GPS signals." 

Kochanski will go to graduate school in the Geology Department at the University of Colorado, Boulder.

For her senior thesis, First Autonomous Telescope at Wallace Observatory: Impact and Preliminary ResultsMolly Kosiarek worked with Professor of Planetary Sciences, and MacVicar Faculty Fellow Richard Binzel, together with Research Scientist and Director of the Wallace Astrophysical Obseravtory Michael Person

"Building and automating a telescope system, the Small AUtonomous Robotic Optical Nightwatcher (SAURON), I spent Summer 2014 building the dome and choosing all of the other components, Fall 2014 doing preliminary testing on the telescope system, and IAP 2015 gathering data. I gathered data on an eclipsing binary star in order to characterize the system; the data gathered was surprisingly good and I then used it to calculate the R magnitude, delta magnitude of primary and secondary peaks, and the period of the binary system."

Molly plans a gap year in the Boston area before attending graduate school. 

For his senior thesis, Controlling Factors on Mesozoic to Cenozoic Metamorphism and Deformation in the Maria Fold and Thrust Belt and Colorado River Extensional Corridor, Southeastern California and Western ArizonaJames Pershken worked with Associate Professor of Geology Oliver Jagoutz.

"The Maria Fold and Thrust Belt at the southern end of the North American Western Cordillera in southeastern California and western Arizona is a poorly understood area characterized by anomalously oriented Mesozoic compressional structures. The Colorado River Extensional Corridor just east is an area of extreme Cenozoic extension and metamorphic core complex emplacement. This study uses new fieldwork and a compilation of existing structural and metamorphic data in an attempt to reconcile these two areas with the history of the Western Cordillera as a whole." 

James has a job lined up working for New Valence Robotics in South Boston.

For her senior thesis, A Near-Ultraviolet Spectroscopic Survey of B-Type AsteroidsAshley Peter worked closely with Julia de León of the Instituto de Astrofísica de Canarias and EAPS advisor Professor Richard Binzel.

"This study obtained new spectroscopic observations of 19 B-type asteroids using the 3.6-meter Telescopio Nazionale Galileo (TNG) in the Canary Islands, Spain to search for variations in spectral slope. This specific category of B-type asteroids is named for typically exhibiting a blue, negative spectral slope; however, recent studies have shown that their slopes vary in different wavelengths. In contribution to a three-part spectroscopic survey, this study focused on the near-ultraviolet wavelength range and found that spectral slope variations do exist. I hope to translate my senior thesis into a publishable paper within the next few months with the help of Julia de León and Professor Binzel."

In the fall, Ashley will be working at Booz Allen Hamilton, a government consulting firm, in Washington, D.C. She is hoping to obtain a master's degree in either business or systems engineering and eventually pursue a career in the commercial space industry. 

For her senior thesis, Variable Star Photometry in a Secondary School CurriculumHollie O'Brien also worked with Professor Richard Binzel.

"I wrote my thesis with the intent to combine my two loves: astronomy and education. My thesis proves that anyone can be a "real" scientist with a shoestring budget. I proved that photometry of variable stars can be performed by anyone using the shoestring budget of only a digital camera along with a laptop. Extrinsic variable star Algol was observed using a 14’’ telescope as well as CCD and had its light curve plotted. In direct comparison, V474 Mon was observed using only a low cost $200 digital camera. Armed with a laptop for data analysis, I plotted V474 Mon's light curve. Lastly, the whole process of research astronomy was applied to a classroom final project setting. Future work includes expanding this thesis into a full semester long astronomy course for high school students." 

In the fall Hollie will begin teaching High School Physics at Uplift Hampton Prep in Dallas, Texas. She is looking forward to starting an Astronomy Club where students can perform original variable star research using the process she outlined in her thesis.

Special thanks, as always, to Jane Connor, EAPS' Lecturer II from Writing Across the Curriculum, for her work supporting and coaching this year's graduating class. Connor, who provides one-on-one writing and effective presentation support to EAPS undergraduates as well as undergraduates in other courses, holds a BA in English from Swarthmore College, and an MA in Languages, Literature and Communication, with an emphasis on Communication Theory, from Columbia University. 

Photos credit: Helen Hill

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