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 five students specializing in areas across the earth, atmospheric and planetary sciences.
Examining the Evidence for Chthonian Planets: Superdense Exposed Exoplanet Cores
Haley A. Bates-Tarasewicz (advisor: Prof. Benjamin Weiss)
Research: Planetary cores are of interest because they provide insight into the internal dynamics and composition of planets. By using mass-radius relationship compositional analysis, this work originally set out to look for evidence of exoplanet exposed iron cores; it stumbled, however, upon potential superdense core candidates (or “Chthonian”cores). We identify 19 potential superdense core candidates, and compare them to the Fossilized Core Theory and the Giant Impact Theory of formation. Additionally, while there are 19 superdense core candidates, they represent only 11 solar systems. We find that both theories plausibly describe the formation of these superdense candidates, and note that all candidates are better constrained, further conclusions cannot be drawn, however, this new type of planet could help inform planetary formation, evolution, and interior dynamic models.
What's Next: "Going to work for JPL."
Analyzing Recent Latitudinal and Seasonal Changes in Simulated Atmospheric Temperatures from a Global Chemistry-Climate Model
Jordan T. Benjamin (advisor: Prof. Susan Solomon)
Research: Recent research has uncovered zonal variability in the seasonal cycle of climate change as a key fingerprint of climate change. We used the Whole Atmosphere Community Climate Model (WACCM), an interactive chemistry-climate model, to examine the cause of this zonal variability and tie it to the forcing impact of new greenhouse gas emissions, and not other agents such as ozone depleting substances. Furthermore we show that WACCM better represents the rate and seasonal cycle of warming better than CMIP5, the current ensemble of the world's best climate models. These results have implications for understanding the attribution and evolution of future climate change, particularly as the world moves to reduce its greenhouse gas emissions and climate change footprint.
What's Next: "I will be I will be pursuing a Ph.D. in Environmental Science and Engineering at Caltech."
Field Measurements of Ice Nucleating Particles: Examining the Potential for Marine Sources
Megan M. Goodell (advisor: Prof. Daniel Cziczo)
Research: My thesis discusses deposition mode ice nucleating particle concentrations measured at Puy de Dôme, France using the SPectrometer for Ice Nuclei (SPIN). These concentrations were most strongly dependent on source region of the sampled air mass; meteorology and gas phase chemistry in the sampling environment were less influential factors. Of particular interest is the distinct difference observed in activated fraction of particles between air masses from continental and marine sources, suggesting that particle properties determined by the source (such as composition) play a key role in a particle’s ice nucleating ability.
What's Next: "I'm not sure what I'll be doing yet!"
Water and Carbon Flux Responses to Soil Moisture Pulses in the Western United States
Apisada Chulakadabba (advisor: Prof. Dara Entekhabi)
Research: In this research, we diagnose plant water and carbon flux responses to soil moisture resource pulses in semi-arid lands of the Western United States. Measurements from twelve AmeriFlux tower (in-situ) and SMAP (satellite) sites across the region are used to estimate relationships between carbon flux and resource availability. Response patterns are shared among the similar ecosystems. The role of carbon flux response to intermittency resource availability can lead to improved estimation of land carbon budgets.
What's Next: "I will travel in the US for three weeks and Asia for the rest of the summer. In the fall, I will start my PhD in Environmental Science and Engineering at Harvard."
Coastal Urban Mercury Cycling and Emissions in Boston, Massachusetts
Emma G. Rutkowski (advisor: Prof. Noelle Selin)
Research: For my thesis research I've been looking at atmospheric mercury concentrations in Boston, MA. In my results I identified the ocean as a major source for local pollution and constrained emission rates.
What's Next: "Next year I'll be working and currently I'm planning to head back to grad school, most likely for atmospheric chemistry, in a year or two."
Photo credit: Megan Jordan
Special thanks, as always, to Jane Connor, EAPS Lecturer from Writing Across the Curriculum, for her work supporting and coaching this year's graduating class. Connor provides one-on-one writing and effective presentation support to EAPS undergraduates as well as undergraduates in other courses.