Geosciences

  • Wang, Xingchen (Tony) (‘13 - ‘15)

    Geosciences

    Xingchen’s research focuses on using nitrogen isotopes to study how the marine nitrogen reservoir has changed in the past ice ages and its relationship with atmospheric CO2; and the nitrogen cycle on modern coral reef ecosystems. Particularly, using state-of-the-art analytical technique, he “reads” the information written in the fossil skeletons of corals (both reef-building corals and deep-ocean corals), which tell us how the ocean nutrient status has changed over glacial-interglacial cycles. He also conducts field studies on modern Bermuda coral reefs, exploring how human activities have changed the symbiotic relationship between coral hosts and their symbionts.

  • Little, Christopher (‘08 - ‘09)

    Geosciences

    The melting of ice shelves from beneath (basal melting) constitutes a loss of ice from the cryosphere and a source of freshwater to the ocean; it also influences ice sheet dynamics. My overarching research goal is to illuminate key oceanographic constraints on the location and rate of basal melting. To date, I have used idealized numerical models to study the influence of ice shelf shape and bathymetry. These idealized simulations have also been used to examine sensitivity to changes in model formulation and parameterizations, improving the prospects for realistic, coupled models of ocean-ice shelf interaction.

  • Fawcett, Sarah (‘08 - ‘10)

    Geosciences

    Sarah’s research focused on the marine nitrogen cycle, and the links between photosynthesis supported by different nitrogen sources and the drawdown of CO2 by the ocean. Nitrogen is a major constituent of all living organisms and a primary determinant of the ecological success of phytoplankton, the base of marine food chains. Biologically available nitrogen has the potential to limit productivity in the surface ocean and determine the composition of phytoplankton communities, thus affecting the transfer of carbon to higher trophic levels, and eventually into the ocean interior. There exists an oceanographic paradigm stating that primary production supported by nitrogen from outside the well-lit surface ocean is equivalent to the amount of carbon that is exported from this surface layer and sequestered at depth.

    Thus discerning the source of N to phytoplankton in various parts of the ocean is potentially very important. Isotope measurements of dissolved and particulate nitrogen pools can tell us about the source of N for photosynthesis, and thus the amount of carbon a particular ecosystem can potentially sequester. She is currently working on measuring species-specific, high-resolution stable isotope signatures of the Sargasso Sea ecosystem using flow cytometry and mass spectrometry. She was also interested in resolving seasonal and temporal changes in phytoplankton N sources, as well as the response of the ecosystem to various perturbations likely to occur as the ocean warms.

  • Medvigy, David (‘16 - ‘16)

    Geosciences

    Medvigy’s research focuses on understanding local-regional scale variability in climate and terrestrial biosphere, with a focus on the processes linking these two components of the Earth system. This research includes study of the relationships between the atmospheric circulation, terrestrial ecology, and biogeochemical fluxes, and how all of these are responding (and are projected to respond) to anthropogenic forcings. His lab addresses these issues through numerical models, including variable-resolution general circulation models, mesoscale meteorological models, and mechanistic models of ecosystem composition, structure, and functioning.

    A specific area of research focuses on the climatic consequences of deforestation. Over the next 40 years, 40% of the Amazon rainforest is projected to become deforested. This has consequences for rainfall, temperature, regional winds, and ecosystem structure and functioning. In addition, these regional-scale changes may impact the large-scale Hadley and Walker circulations, and thus have global consequences. To complicate matters, the net response to deforestation may strongly depend on both the total area deforested and the spatial pattern of deforestation. Medvigy is currently using variable-resolution general circulation models to address these problems.

    Another key area of research involves high-frequency climate variability. Daily fluctuations in sunshine, rainfall, and temperature are strongly coupled to ecosystem function, with effects that accumulate through annual and decadal time scales. Medvigy is currently seeking to elucidate the consequences of the projected changes in daily-scale variability over the next 100 years for terrestrial ecosystem structure, composition, and functioning.

  • Maloof, Adam

    Geosciences

    Adam Maloof joined the faculty in 2006. Research in Maloof’s Earth history group relies on original field observations, at the scale of maps, rock outcrops, and thin sections.

    The group’s current focus involves using sedimentary and volcanic rocks to extract information about Earth’s ancient magnetic field and the relative motion of continents, perturbations to the global carbon cycle, and the coevolution of life and climate.

  • Fueglistaler, Stephan

    Geosciences

    Research Interests: Atmospheric problems ranging from cloud microphysics and radiation to large-scale dynamics; mechanisms of interactions between different processes on different scales, and how this interaction leads to the climate as we know it. Global warming; stratospheric water; clouds; Kelvin waves; tracers and dynamics; tropical tropopause layer; and the global hydrological cycle.

  • Yan, Yuzhen (‘15 - ‘17)

    Geosciences

    Yuzhen is interested in the Earth’s climate history 1 million years ago. He uses ice core records from Antarctica to reconstruct polar temperature, greenhouse gas concentration, and atmospheric composition in collaboration with researchers across the country. His research will shed light on how greenhouse gas concentrations and the Earth’s climate state co-varied before human’s impact on carbon cycle . Here at Princeton, Yuzhen measures the elemental and isotopic composition of major gases (nitrogen, oxygen, and argon) to provide key constraint on the timescale of ice cores.