Graduate Student of the Month
Joshua Méndez Harper - April 2017
Joshua Méndez Harper started his graduate career in the School of Earth and Atmospheric Sciences at Georgia Tech after completing his BS in Electrical Engineering from Boston University. Josh has received a National Science Foundation Graduate Fellowship, an outstanding paper award from the American Geophysical Union (AGU) for a talk he presented, and Blue Water Computational Science Fellowship.
Joshua’s research interest are granular electrification, volcanic lightning, obscure and difficult problems in electrostatics, planetary volcanism, molten-fuel coolant interactions, Internet of things, geophysical instrumentation CubeSATs, and electromagnetic earthquake precursors. He is currently working with Dr. Josef Dufek on multiple projects and publications.
In his spare time, Joshua enjoys building cigar box theremins and diddley bows. He is also interested in learning and teaching Nahuatl, Native American creation myths and literature, and the Klingon language.
Hussein Sayani - March 2017
Hussein Sayani is a PhD candidate and NSF Graduate Research Fellow working with Dr. Kim Cobb. He received his B.S. in Earth and Atmospheric Science from Georgia Tech and studies paleoclimatology.
Hussein specializes in using fossil corals to investigate past climate changes. The tropical Pacific has as profound impact on global temperature and rainfall patterns. However, natural climate variability in this region of the world remains poorly understood due to the scarcity of historical temperature, rainfall, and wind observations. His work focuses on using fossil corals to provide independent records of temperature and hydrology variability in the central tropical Pacific over the last 400 years. These records will provide much-needed constraints on natural climate variability in the tropical Pacific, allowing researchers to identify human-driven climate trends and improve regional climate predictions.
In his spare time, Hussein enjoys baking, hiking, working out and concerts.
Sebastian Ortega Arango - January 2017
The following is an exerpt from the College of Sciences story by A. Maureen Rouhi, Ph.D. Click here to read the entire story.
Yun Hee Park - December 2016
Yun Hee is a 3rd year graduate student working under the advisement of Dr. Irina Sokolik. Her line of research includes remote sensing and numerical modeling related to biomass burning, with recent research looking at impacts of smoke on UV fluxes. Yun Hee earned her B.A in Atmospheric Science from Yonsei University and a M.A in Atmospheric science from Univ. of Alabama in Huntsville. Working with Dr. Sokolik, Yun Hee published a paper last summer, which title is “Toward Developing a Climatology of Fire Emissions in Central Asia”.
In Yun Hee’s spare time, she enjoys cooking and spending time with his family and is expecting their second baby in December.
Giovanni Liguori - November 2016
Giovanni Liguori is a 4th year graduate student in EAS. He received his B.S. in Environmental Sciences, summa cum laude, from University of Naples “Parthenope” in Italy. While at Georgia Tech, he has been awarded the Domenica Rea D'Onofrio Fellowship and written 8 peer-reviewed publications that can be viewed on his webpage at www.oceanography.eas.gatech.edu/gianni/pubblications/
His scientific interest is oceanography and climate dynamics from interannual to decadal timescales. His current project focuses on the mechanisms responsible for the observed Pacific decadal variability, which impact long-term transitions in marine ecosystems and influence the statistics of weather including ocean and atmosphere extremes such as strong droughts, hurricanes and marine heatwaves. Specifically, combining observations and model outputs, he is studying how tropical and extra-tropical Pacific climate modes interact to produce decadal variability.
In addition to his principal research topic, the Pacific decadal climate variability, Giovanni recently broadened his research horizon by involving himself in a project aimed to study the impact of climate change on Peruvian glaciers. He gained firsthand experience by attending a workshop in Lima, Peru, and visited the Andean glacier of Artesonraju, hiking up to an altitude of about 18,000 feet. The project was broadcasted by a Peruvian news channel.
In his spare time, Giovanni enjoys cooking and hosting events for his friends, playing soccer, racquetball, traveling, and hiking.
Shannon Valley - October 2016
Shannon Valley is a 3rd year PhD student in EAS. Her line of research is paleoclimate/paleoceanography which involves reconstructing past ocean circulation using geochemical proxies in order to understand the ocean’s role in abrupt climate change. Recently she presented the poster "Timing of Deglacial AMOC Variability from a High-resolution Seawater Cadmium Reconstruction" at the International Conference on Paleoceanography.
Shannon received a BA in Political Science and International Studies (2007) from Northwestern University and an MS in EAS awarded Summer 2016 under the advisement of Dr. Jean Lynch-Stieglitz. She has worked for five years in NASA’s Office of Legislative and Intergovernmental Affairs in Washington, DC and was awarded the NASA Exceptional Achievement Medal in 2014 for communicating NASA science (including Earth science) on Capitol Hill. During her time in DC, she also spent six months working in the West Wing, for the Domestic Policy Council in the Executive Office of the President. In 2015 Shannon was awarded the NSF Graduate Research Fellowship. She is currently the 2016-2017 University Relations Chair for Georgia Tech’s Black Graduate Student Association.
Her interests lie at the intersections of science and society. She spends a lot of time thinking about how scientific understanding of Earth systems can support those who are least equipped to handle changes to our climate and how our political and economic systems may help or hinder those efforts. In her spare time, Shannon enjoys traveling, yoga, hiking, and plane spotting.
Zachary Meeks - September 2016
Zachary Meeks is a 2nd year Ph.D. student researching Space Plasma Physics, under the direction of Dr. Sven Simon. His undergraduate degree is a B.S. in Physics (Astrophysics) from Georgia Tech. While in undergrad he published “Is J Enough? Comparison of Gravitational Waves Emitted Along the Total Angular Momentum Direction with Other Preferred Orientations” (2012) and “Efficient Asymptotic Frame Selection for Binary Black Hole Spacetimes using Asymptotic Radiation” (2011). As a graduate student he has published “A Comprehensive Analysis of Ion Cyclotron Waves in the Equatorial Magnetosphere of Saturn” (2016).
Zach is the Planetary Science Rep for GEAS (the graduate student organization for the School of Earth and Atmospheric Sciences) and in his spare time he enjoys playing baseball, dealing blackjack, scuba diving with sharks, and woodworking.
Sebastian Ortega - April 2016
Sebastian Ortega started his graduate degree in Fall 2011. His line of research is focuses on Tropical Meteorology with Dr. Peter Webster. Specifically, he studies the South Asia Monsoon, and is interested both in its intra-seasonal and intra-annual variability. Within the research group, they study closely what happens in the upper troposphere as well as in the lower troposphere, and try to understand how both might interact. They have recently submitted a paper to the Journal of Climate, where they show that quasi-biweekly oscillation over the monsoon regions occur simultaneously with quasi-biweekly oscillations of the monsoon anticyclone.
Sebastian is a Civil Engineer from the Universidad Nacional de Colombia in Medellin. He says that his Colombian university also has a very good Geophysics School, focusing mostly in Hydrology, this is where he became interested in Earth Sciences. In his senior year of undergrad, he worked in Physical Limnology and studied how rivers can affect the thermal stratification of reservoirs. He is also very interested in Physics and Dynamical systems. Sebastian did his Ph.D. minor in Physics and always tries to incorporate what he’s learned here into research. In his spare time, Sebastian enjoys playing guitar, rock climbing, and reading.
Jia He - March 2016
Jia He is a 5th year Ph.D. candidate who received her B.S. in Atmospheric Sciences from Nanjing University in Nanjing, China. She is currently being advised by Dr. Robert Black with whom she co-published an article with entitled "Characterizing Arctic Spring Onset" which can be found in the Journal of Climate (2015). She has been working on identifying and characterizing rapid spring onset events and associated atmospheric dynamical processes in the Arctic. In her spare time, Jia enjoys working out at the gym and reading fiction novels.
Emily Christ - February 2016
Emily Christ is a 5th year graduate student whose line of research entails applyingweather forecast data to problems in agriculture. She earned herBachelor and Master of Science in Engineering, both from the University of Alabama in Huntsville. Emily worked as an environmental engineering consultant prior to relocating to Atlanta with her husband, Joey. Currently she is a licensed Professional Engineer in both Alabama and Georgia.
Emily has one publication in the Journal of Cotton Science which was released in November 2015 titled ‘Using Precipitation Forecasts to Irrigate Cotton’. It explores the possibility of using weather forecasts as irrigation planning aids. Her research has been supported by Cotton, Inc. and she’s had the privilege to work with faculty and staff at the University of Georgia, UGA’s Stripling Irrigation Research Park, North Carolina State University, Auburn University, the University of Arkansas, and Mississippi State University while pursuing her degree.
She recently submitted a second paper to the Agronomy Journal that uses cotton canopy temperature forecasts to predict heat stress in cotton. In her spare time, she enjoys volunteering at the Peachtree City Treasures retail store for Wellspring Living. Wellspring Living helps domestic sex trafficking victims and the ‘at risk’ develop the courage to move forward and the confidence to succeed. Profits from the retail stores help support the ministry. Emily also enjoys serving at Peachtree City First Baptist Church, working out at Pure Barre and gardening.
James Hite - January 2016
James Hite is a 5th year graduate student whose line of research includes aerosols, clouds, and climate. His thesis will focus on thermodynamics of secondary organic aerosol. James received a B.S. in EAS in 2011 and an M.S. in EAS in 2012,both under the direction of Dr. Thanos Nenes. Some of his accomplishments include Air & Waste Management Association’s Southern Section Scholarship (August 2015), NASA Earth and Space Science Fellowship (May 2015), National Instruments Certified LabVIEW Associate Developer (June 2013), Glen Cass Award (April 2013), and Student Poster Competition Winner at the American Association for Aerosol Research 31st Annual Conference (October 2012).
His future projects include field deployment this spring to Korea with aerosol research group from NASA Langley: KORUS-AQ. He is currently working on publications based on previous field deployment with NASA group, collaborative smog chamber experiments at Caltech, and ongoing development of a measurement & modeling technique for estimating organic aerosol volatility.
James says that other interests of his include arguing pointlessly about things like current events, politics, and philosophy. Anything that tends to evoke a visceral response in folks, for instance, cats are better than dogs. He is both the graduate student senator for the EAS department and the Secretary of Graduate SGA. James enjoys listening to podcasts or music during work. His current music playlist includes both Fleshgod Apocalypse and The J. Gelis Band. During his spare time, he chooses video games as his entertainment of choice.
Lucas Luizzo - December 2015
Lucas Liuzzo is a 2nd year PhD student studying space physics, more specifically moon-magnetosphere interactions, under the advisement of Dr. Sven Simon. He graduated with a Bachelor's of Science and Engineering from the University of Michigan in 2014. While there, he studied thermosphere-ionosphere coupling in the Earth's upper atmosphere. Currently, he models the interaction between Callisto (a Galilean moon of Jupiter) and the Jovian magnetosphere.
Lucas has a peer-reviewed article in JGR - Space Physics that he published as an undergraduate student at Michigan. Additionally, a paper in JGR - Space Physics was just accepted to be published and should be available shortly. This most recent manuscript is a culmination of the work he’s done so far while in EAS since he arrived last year. It focuses on quantifying the effect that Callisto's atmosphere has on the plasma signatures around the moon, something that has never been done before! For this research, he received 1st prize for best presentation at the International School/Symposium for Space Simulations, held this past summer in Prague, Czech Republic.
Lucas is also the chairman of the GEAS (Graduates in Earth and Atmospheric Sciences) committee. GEAS focuses on enhancing graduate student life and fosters professional and social development for graduate students in EAS. In his spare time, he loves to cook, bake various breads, and he enjoys running.
Yohei Takano - November 2015
Yohei Takano is a 4th year graduate student whose line of research involves working with Dr. Takamitsu Ito on understanding large-scale ocean biogeochemical cycles, including dissolved oxygen, nutrients, and carbon cycles. The main focus of his research is to understand how ocean biogeochemical cycles responds to climate variability and long-term climatic change, such as global warming. Currently, Yohei is working on understanding how oxygen minimum zones evolve under the inﬂuence of human induced climate change, which could involve both physical and biological response in the ocean.
Before coming to Georgia Tech, Yohei obtained an M.S. in Atmospheric Sciences from Colorado State University. He says that training from the atmospheric science ﬁeld really helped him on developing interdisciplinary understanding and research approach on coupled processes between climate change/variability and ocean biogeochemical cycles.
During his spare time he enjoys cooking and eating. Yohei says cooking helped him communicate with people from different cultures and he loves to share recipes with his friends. Most recently, Yohei is wrapping up his research for publications and his dissertation.
Lujendra Ojha - October 2015
Lujendra (Luju) Ojha is a 3rd year PhD student in Planetary Science with a Volcanology minor. He received his BS in Geo-physics with a Planetary Science minor from the University of Arizona in 2012. With his advisor Dr. James Wray, his main research interest is understanding the evolution of terrestrial planets. He’s passionate about studying present day geological features on planetary bodies across the solar system. Luju has worked on Earth, Mars, Moon, asteroids, comets, and has also classified various meteorites. His greatest accomplishment to date was discovering streams of water on Mars, by understanding the formation mechanism of Recurring Slope Lineae (RSL).
Mr. Ojha has several peer-reviewed publications and awards which include a Research Excellence Award and Lunar and Planetary Institute Career Award from the National Science Foundation. When he was at the University of Arizona he received an Honorary Presidents Award and placed first in the Physical Science Research Annual Student Showcase.
Most recently Luju has gone to France for a month long NSF-GROW Fellowship.
Pamela Grothe - September 2015
Pamela Grothe is a 4th year PhD candidate currently researching paleoclimate - reconstructing tropical Pacific climate through the last 6,000 years using geochemistry from fossil corals. She received a B.S. in geology from Mary Washington College, an M.S. in geology from the University of Colorado and was a part of the Sigma Delta Epsilon/Graduate Women in Science Fellowship for the 2014-2015 academic year. Pamela currently has a paper in review in G-cubed titled, "A comparison of rapid-screen 14C and U/Th dates: Implications for paleoclimate reconstruction."
For her current project, she is reconstructing the El Nino Southern Oscillation (ENSO) between 2000 and 6000 years ago from fossil corals from Christmas Island, central tropical Pacific. Future projections of the strength of ENSO, the largest source of year-to-year climate extremes, are highly uncertain. The instrumental record of ENSO activity is too short in time to resolve potential anthropogenic trends in ENSO properties. Coral oxygen isotopes, alternatively, provide monthly-resolved ENSO activity, and extend back 7000 years ago from islands in the central tropical Pacific. Pamela says her initial results suggest a ~60% reduction in ENSO activity between 3000 and 5000 years ago. She goes on to say, “This work is significant as it will allow us to uncover mechanisms behind past ENSO variability and refine simulations of ENSO in climate models.”
In her spare time, Pamela enjoys running, biking, swimming, hiking, camping, kayaking, and SCUBA diving. She also exclaims, “I love my yellow lab rescue dog, Cooper!”
Emily Saad - April 2015
The ultimate fate of materials in soils and sediments has relevance to both contaminant transport processes and global biogeochemical cycles. Consequently, we focus on the transformation of specific species in these subsurface environments. Chromium has become the second most common metal contaminant in the United States because of its utility in many industrial processes motivating us to study the stability of chromium containing solids. Furthermore, we are interested in unraveling an unclear process involving silica that occurs in marine sediments and may directly influence ocean pH.
Before returning to school to complete her B.S. in Chemistry at Georgia Tech (2010), Emily worked on various organic farms assisting in the development of sustainable farming practices and also at USU’s Water Research Lab collecting data for hydraulic and habitat simulations. Emily moved to New Zealand before entering into and completing an M.S. program in Chemistry at Northern Arizona University (2013). Emily is now working towards a PhD with Dr. Yuanzhi Tang and enjoys live music, tap dancing, and teaching step aerobics.
Melissa Warren - March 2015
My research focuses on the interactions between nitrogen and methane cycling in a northern latitude peatland in northern Minnesota, the site of the DOE Spruce and Peatland Responses Under Climatic and Environmental Change (SPRUCE) experiment. SPRUCE is a large-scale mesocosm project studying the effects of increased CO2 and temperatures on a nutrient-poor peatland ecosystem. Peatlands and permafrost regions have gained increased interest due to the predicted rise in temperature expected to impact these regions in the next century. The future of peatland’s role in the sequestration or release of carbon to the atmosphere is uncertain. For my Master’s research, I measured spatial and temporal variation in nitrogen fixation rates under varying temperature and methane concentrations for SPRUCE peat samples. My PhD research will investigate the response of microbial nitrogen and methane cycling to warming and elevated CO2.
Melissa I graduated cum laude from Kennesaw State University in Kennesaw, Georgia with a B.S. in Biology. She serves on the student committee for the 2015 Southeastern Biogeochemical Symposium and is currently completing her Master’s work in the group of Dr. Jennifer Glass and will begin her PhD in the summer. Dr. Joel Kostka and Dr. Chris Schadt (ORNL) are members on her Master’s committee. When Melissa is not working on her research, she can be found anywhere outside, running, hiking, horseback riding, and relaxing with friends and family.
Mary Benage -- March 2015
My research aims to understand the thermal evolution of pyroclastic flows during a volcanic eruption. Pyroclastic flows are composed of hot gas and rocks, and are fast moving currents that propagate due to the density differential between the flow and the ambient atmosphere. Due to the hazards and inability to see within a pyroclastic flow, we do not know how the temperature of the flow evolves or how particles are concentrated. Therefore, we do not fully understand the associated dynamics and hazards. I use multiphase numerical models that are constrained with field data and observations to study the internal physics and dynamics of the pyroclastic flows. I specifically work to examine the thermal evolution in order to constrain the concentration of particles and efficiency of the flows to entrain colder ambient air during the 2006 eruption of Tungurahua volcano, Ecuador.
Mary graduated summa cum laude from Mesa State College in Grand Junction, CO with a B.S. in Geology. She then did a one-year post-baccalaureate internship at Los Alamos National Laboratory. She is currently finishing up her Ph.D. in Dr. Dufek’s volcanology group and serves as the chair of the Graduates in EAS group. Mary received the Department of Energy Computational Science Graduate Fellowship and National Science Foundation Graduate Research Fellowship. In her spare time, Mary enjoys running, hiking, volunteering, and traveling.
Salah Faroughi -- December 2014
The amount of volatiles and the dynamics of bubbles play a significant role on the transition between different volcanic eruption behaviors. The transport of exsolved volatiles through zoned magma chambers is complex and remains poorly constrained. Salah, in his PhD study, mainly focuses on the different transport of volatiles under two end member regimes: crystal-poor systems (bubbles form a suspension) versus crystal-rich reservoirs (multiphase porous media flow). To contrast the differences between the transports of exsolved volatiles in both regimes, the transport of a non-wetting phase in suspensions and porous media are characterized, separately, and then the effect of the transition zone on the over all flux is taken into account.
Investigating the dynamics of multi-particle systems to correctly integrate the effect of particle interactions on the rheological, mechanical and thermal properties of condensed matter is another aspect of his research interest.
Salah completed his B.S. in Mechanical Engineering at Urmia University (Iran) in 2009, his M.S. in Mechanical Engineering at Sharif University of Technology (Iran) in 2011, and recently completed another M.S. in Earth and Atmospheric Sciences at Georgia Tech.
Ryan Cahalan -- November 2014
The overarching goal of my research is to characterize and quantify the dynamics of subaqueous explosive volcano (aka Neptunian) eruptions. Neptunian eruptions are far less understood than their subaerial counterparts, yet equally hazardous. This discrepancy arises due to the near impossibility of collecting real-time eruption data. To gain insight into these systems, I am developing a multiphase fluid dynamics model, as well as a Neptunian Eruption Simulation Tank, to simulate (1) how fragmentation occurs (2) how material and heat are transported/deposited, and (3) how tsunamis are generated, during these eruptions. The overall goal is to use the model in concert with the experiments and field data to reproduce the 2012 eruption dynamics at Havre Volcano, New Zealand, the largest observed submarine eruptions in the last century.
Ashok Rajendar -- October 2014
I investigate the complex interactions between the solar wind and outer planet magnetic fields using sophisticated computer simulations. Planetary magnetospheres exhibit a wide variety of phenomena, thus functioning as natural laboratories in which we can investigate the behavior of magnetized plasma under different conditions. Understanding magnetospheric conditions is also vital to planning spacecraft missions, as high energy plasmas can pose a substantial radiation hazard. My thesis research focuses on understanding the global implications of the production and transport of new plasma in Saturn's magnetosphere. The presence of the Cassini spacecraft in orbit around Saturn provides us with valuable data with which to validate our results and develop our numerical tools.
Ashok completed his B.S. in Mechanical Engineering at Cornell University in 2006 and his M.S. in Mechanical Engineering at Georgia Tech in 2011.
Keaton Belli -- 2014
My research interests revolve around developing sustainable solutions for environmental problems by utilizing the symbiosis between humans and nature. In the Taillefert lab I study how we can use uranium-breathing bacteria to clean up uranium-contaminated groundwater at nuclear facilities. Cost-effective remediation strategies that address nuclear waste spills are necessary to ensure that nuclear power is a safe alternative to fossil fuels. My dissertation investigates the duality of uranium as both a toxic contaminant and an energy source for bacteria and the geochemical conditions that control the fate of uranium in the subsurface.
Keaton completed his B.S. in Earth and Atmospheric Sciences at Georgia Tech in 2010 and recently received the Best Talk Award at the 2013 EAS Graduate Student Symposium. He currently serves on the steering committee for the Southeastern Biogeochemistry Symposium and is the founder and organizer of the Careers in Science seminar series. Outside of the lab, Keaton can be found throwing pottery, globetrotting, or rocking out to live music.
Jessica Moerman -- 2013
“My research focuses on discovering how tropical rainfall and atmospheric circulation patterns varied over the past two millennia. Since data from weather stations is only available for the last several decades, I use geologic archives like stalagmites to obtain information about Earth’s climate history. Stalagmites contain a record of past rainfall variability in the oxygen isotopic chemistry of their calcite layers. To better understand how oxygen isotopes reflect climate variability, I also conduct comparison studies between instrumental precipitation data and the oxygen isotopic chemistry of modern rainfall and cave dripwater. This research has taken me across the world to conduct fieldwork in places like Borneo and Papua New Guinea.”
Jessica graduated summa cum laude from the University of Tennessee at Chattanooga with B.S. degrees in Chemistry and Geology. She is currently a Ph.D. candidate in Dr. Cobb’s paleoclimate lab. She has received several prestigious awards, including the Barry M. Goldwater Scholarship, National Science Foundation Graduate Research Fellowship, Georgia Institute of Technology President’s Fellowship, and the P.E.O. Scholar Award.
Photo credit Jerry Wallace
Chastity Aiken -- 2013
Chastity Aiken is currently pursuing a PhD in Earth and Atmospheric Sciences at Georgia Tech. Her research with advisor Zhigang Peng focuses on studying deep tectonic tremor, a subtle fault movement in the lower crust, and its interactions with damaging earthquakes. Her work includes identifying tremor sources that are triggered by seismic waves of a large, distant earthquake along strike-slip faults where tremor has not been previously observed. In 2012, she installed seismometers in Costa Rica that recorded a magnitude 7.6 earthquake. Her research has covered much of the Western Hemisphere and has been published in international journals such as Nature Geoscience and Geophysical Research Letters. She has won a National Science Foundation Graduate Research Fellowship, as well as an ARCS Foundation Scholarship. In her spare time, she volunteers for Trees Atlanta, tutors high school students in physics and math, and engages in rock climbing.