PhD, University of Alaska Fairbanks, 2019. Dr. Clark is working with Dr. Kristin Laidre to develop a method for estimating age at sexual maturity in Arctic mammals using concentrations of zinc and lead in teeth. The ability to estimate age at maturity is important for tracking changes in the status of wildlife populations, and this parameter is a key piece of information for many population models, which allow for projections of population status into the future. This information is currently difficult to obtain for many species, particularly those that live in remote and difficult to access locations such as the Arctic. The primary goal of this research is to generate a new tool for researchers and wildlife managers to more effectively monitor and manage populations of Arctic mammals, which represent critical subsistence resources for many northern communities and are key players in Arctic food webs.
PhD, Climate Science, Massachusetts Institute of Technology, 2018. With David Battisti, I am studying the interaction of regional tropical rainfall with the global tropical energy balance. Tropical rainfall provides water to billions of people, and connecting its regional distribution and dynamics to the global climate is one of the central challenges of climate science. The global tropical energy balance places strong constraints on the pattern and dynamics of tropical rainfall averaged across longitudes, explaining the location of the tropical rainfall maximum, for example, but has relatively little power to describe regional rainfall dynamics. Nonetheless, regional rainfall patterns are tied to their local energy and water vapor budgets; my research seeks to better understand how these regional patterns interact and are organized in response to larger-scale climate boundary conditions, such as the seasonal distribution of sunlight.
PhD, Earth Sciences, University of Minnesota, 2018. Dr. Hoffman is working with Dr. Randelle Bundy, UW School of Oceanography, and Dr. Jospeh Resing, JISAO-NOAA, to examine the mechanisms and kinetics of how diffuse flow hydrothermal iron in the Southern Pacific Ocean is stabilized and potentially upwelled in the Southern Ocean, fueling phytoplankton primary production. Phytoplankton are key players in the global carbon cycle but are often growth limited due to iron-poor surface waters. Hydrothermal vents could, therefore, be a previously unrecognized nutrient source to the surface ocean and play an important role in the global carbon cycle. Currently, two mechanisms, nanoparticles and organic complexation, are hypothesized to be responsible for basin-scale transport of hydrothermal iron. Dr. Hoffman will investigate iron-ligand (e.g. organics) relationships, ligand characterization, and kinetics of these reactions in hydrothermal plumes. The results from this research will advance our current understanding of how hydrothermal vents influence global geochemical cycles, and impact phytoplankton growth in the surface waters.
PhD, Marine Biosciences, University of Delaware, 2019. Dr. McAllister is working with Dr. Carol Stepien, Ocean Environment Research Division Leader at NOAA/PMEL, and Dr. Dave Butterfield, UW JISAO, researching species composition, diversity, and connectivity of microbial, fish, and invertebrate communities in chemosynthetic hydrothermal environments, a.k.a. the dark biosphere. Hydrothermal plumes and methane seeps are habitats with a high flux of reduced chemicals that can be used by chemoautotrophic bacteria and archaea to produce energy for growth, supporting a broader biological community. Understanding the links between these communities and the hydrothermal environment is key to understanding their impacts on coastal fisheries and the blue economy. Dr. McAllister’s research uses eDNA metabarcoding, RADSeq of selected taxa, and metagenomics to address these interests.
PhD, Oceanography (specialization Climate Science), Scripps Institution of Oceanography, 2018. Dr. Sanchez is interested in paleo-climate variability, tropical climate dynamics, and the development of geochemical archives to interpret past change in Earth’s climate system. Dr. Sanchez is working with Dr. Greg Hakim, UW Atmospheric Sciences, and Dr. Casey Saenger, JISAO, on a coral-based paleoclimate data assimilation project aiming to reconstruct climate variability in the tropical oceans. Climate models indicate that the tropics host some of the most robust responses to climate change, but monitoring low frequency change in the tropical oceans is difficult given the sparsity of observations prior to the satellite era. This work offers a new means of assessing of tropical climate variability; the results of this work will improve understanding of historical hydroclimate and surface temperature variations, the response of the tropics to forced change, and coral geochemistry- instrument calibration.