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Molecular determination of marine iron ligands by mass spectrometry
(Massachusetts Institute of Technology, 2016)
Marine microbes produce a wide variety of metal binding organic ligands that regulate the solubility and availability of biologically important metals such as iron, copper, cobalt, and zinc. In marine environments where ...
The remineralization of marine organic matter by diverse biological and abiotic processes
(Massachusetts Institute of Technology, 2017)
While aerobic respiration is typically invoked as the dominant mass-balance sink for organic matter in the upper ocean, many other biological and abiotic processes can degrade particulate and dissolved substrates on globally ...
Insights into vitamin B₁₂ production, acquisition, and use by marine microbes
(Massachusetts Institute of Technology, 2012)
The distribution and magnitude of marine primary production helps determine the ocean's role in global carbon cycling. Constraining factors that impact this productivity and elucidating selective pressures that drive the ...
Boundary layer dynamics and deep ocean mixing in Mid-Atlantic Ridge canyons
(Massachusetts Institute of Technology, 2013)
Physical oceanographers have known for several decades the total amount of abyssal mixing and upwelling required to balance the deep-water formation, but are still working to understand the mechanisms and locations-how and ...
Inferring ocean circulation during the last glacial maximum and last deglaciation using data and models
(Massachusetts Institute of Technology, 2017-02-22)
Since the Last Glacial Maximum (LGM, ~ 20,000 years ago) air temperatures warmed, sea level rose roughly 130 meters, and atmospheric concentrations of carbon dioxide increased. This thesis combines global models and ...
Physical influences on phytoplankton ecology : models and observations
(Massachusetts Institute of Technology, 2013)
The physical environment in the oceans dictates not only how phytoplankton cells are dispersed and their populations intermingled, but also mediates the supply of nutrients to the surface mixed layer. In this thesis I ...
Late Holocene hurricane activity and climate variability in the Northeastern Gulf of Mexico
(Massachusetts Institute of Technology, 2011)
Hurricane activity in the Northeastern Gulf of Mexico and its relationship to regional and large-scale climate variability during the Late Holocene is explored. A 4500-year record of hurricane-induced storm surges is ...
Transformations of mercury in the marine water column
(Massachusetts Institute of Technology, 2014)
Methylation of mercury (Hg) in the marine water column has been hypothesized to serve as the primary source of the bioaccumulating chemical species monomethylmercury (MMHg) to marine food webs. Despite decades of research ...
Heterogeneous reservoirs in the marine carbon cycle
(Massachusetts Institute of Technology, 2014)
Understanding the fate of primary production in the ocean is a challenging task because once produced, organic material is oxidized over timescales which range from minutes, to millions of years. This timescale diversity ...
Influences on the oceanic biogeochemical cycling of the hybrid-type metals, cobalt, iron, and manganese
(Massachusetts Institute of Technology, 2012)
Trace metal cycling is one of many processes that influence ocean ecosystem dynamics. Cobalt, iron, and manganese are redox active trace metal micro-nutrients with oceanic distributions that are influenced by both biological ...