Zanna Chase | |
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| Alma mater | Columbia University |
| Scientific career | |
| Institutions | University of Tasmania |
| Thesis | Trace elements as regulators (Fe) and recorders (U, Pa, Th, Be) of biological productivity in the ocean (2001) |
Zanna Chase is an ocean-going professor of chemical oceanography and paleoceanography at the Institute of Marine and Antarctic Science, University of Tasmania, Australia. She has undertaken over 20 voyages on research vessels.
She completed her undergraduate studies in Mathematics and Biology at McGill University in Canada in 1993. [1] She then completed her Master's degree in biological oceanography at McGill University in 1996 working on how iron controls marine protozoans. [2] She undertook her PhD in chemical oceanography and paleoceanography at Lamont–Doherty Earth Observatory where she worked on trace elements and primary production in marine ecosystems. [3] Prior to joining the newly formed Institute of Marine and Antarctic Science, University of Tasmania in 2010, she was on the faculty at Oregon State University. [1]
Her research focusses on the interaction between chemical cycles and biological activity, the study of biogeochemistry. She is interested in how the biogeochemical changes in the Southern Ocean influence climate, and are also affected by climate, in the modern ocean. She also studies past biogeochemical changes in the ocean, the study of paleoceanography. A significant focus of her work has been on understanding the role of iron as a micronutrient in the oceans. [4] Another focus of her work is on the exchange of carbon dioxide between the oceans and the atmosphere and the role of carbon sequestration in the oceans on controlling natural climate changes over the glacial-interglacial cycles. [5] She uses a range of geochemical proxies analysed on ocean waters and sediment cores including long-lived, naturally occurring radioisotopes like Thorium isotopes to reconstruct particle flux, and redox-sensitive metals such as Manganese and Uranium to reconstruct ocean oxygen levels. She is also involved in research to improve our understanding of trace metal proxies through participation in the international GEOTRACES program. She has participated in >20 voyages on a range of different research vessels including the Australian blue water vessel RV Investigator. [6]
The biological pump, also known as the marine carbon pump, is, in its simplest form, the ocean's biologically driven sequestration of carbon from the atmosphere and land runoff to the ocean interior and seafloor sediments. It is the part of the oceanic carbon cycle responsible for the cycling of organic matter formed mainly by phytoplankton during photosynthesis (soft-tissue pump), as well as the cycling of calcium carbonate (CaCO3) formed into shells by certain organisms such as plankton and mollusks (carbonate pump).
The mesopelagiczone, also known as the middle pelagic or twilight zone, is the part of the pelagic zone that lies between the photic epipelagic and the aphotic bathypelagic zones. It is defined by light, and begins at the depth where only 1% of incident light reaches and ends where there is no light; the depths of this zone are between approximately 200 to 1,000 meters below the ocean surface.
High-nutrient, low-chlorophyll (HNLC) regions are regions of the ocean where the abundance of phytoplankton is low and fairly constant despite the availability of macronutrients. Phytoplankton rely on a suite of nutrients for cellular function. Macronutrients are generally available in higher quantities in surface ocean waters, and are the typical components of common garden fertilizers. Micronutrients are generally available in lower quantities and include trace metals. Macronutrients are typically available in millimolar concentrations, while micronutrients are generally available in micro- to nanomolar concentrations. In general, nitrogen tends to be a limiting ocean nutrient, but in HNLC regions it is never significantly depleted. Instead, these regions tend to be limited by low concentrations of metabolizable iron. Iron is a critical phytoplankton micronutrient necessary for enzyme catalysis and electron transport.
Iron fertilization is the intentional introduction of iron to iron-poor areas of the ocean surface to stimulate phytoplankton production. This is intended to enhance biological productivity and/or accelerate carbon dioxide sequestration from the atmosphere. Iron is a trace element necessary for photosynthesis in plants. It is highly insoluble in sea water and in a variety of locations is the limiting nutrient for phytoplankton growth. Large algal blooms can be created by supplying iron to iron-deficient ocean waters. These blooms can nourish other organisms.
The Bermuda Atlantic Time-series Study (BATS) is a long-term oceanographic study by the Bermuda Institute of Ocean Sciences (BIOS). Based on regular research cruises, it samples an area of the western Atlantic Ocean nominally at the coordinates 31°40′N64°10′W. The cruise programme routinely samples physical properties such as ocean temperature and salinity, but focuses on variables of biological or biogeochemical interest including: nutrients, dissolved inorganic carbon, oxygen, HPLC of pigments, primary production and sediment trap flux. The BATS cruises began in 1988 but are supplemented by biweekly Hydrostation "S" cruises to a neighbouring location that began in 1954. The data collected by these cruises are available online.
Paul G. Falkowski is an American biological oceanographer in the Institute of Marine and Coastal Sciences at Rutgers University in New Brunswick, New Jersey. His research work focuses on phytoplankton and primary production, and his wider interests include evolution, paleoecology, photosynthesis, biogeochemical cycles and astrobiology.
Particulate organic matter (POM) is a fraction of total organic matter operationally defined as that which does not pass through a filter pore size that typically ranges in size from 0.053 to 2 millimeters.
Marine biogeochemical cycles are biogeochemical cycles that occur within marine environments, that is, in the saltwater of seas or oceans or the brackish water of coastal estuaries. These biogeochemical cycles are the pathways chemical substances and elements move through within the marine environment. In addition, substances and elements can be imported into or exported from the marine environment. These imports and exports can occur as exchanges with the atmosphere above, the ocean floor below, or as runoff from the land.
Karen Frances Wishner is an American oceanographer currently at University of Rhode Island and an elected fellow of the American Association for the Advancement of Science. Her interests include coastal shelf and zooplankton behavior and environment, and has published her findings.
The Joint Global Ocean Flux Study (JGOFS) was an international research programme on the fluxes of carbon between the atmosphere and ocean, and within the ocean interior. Initiated by the Scientific Committee on Oceanic Research (SCOR), the programme ran from 1987 through to 2003, and became one of the early core projects of the International Geosphere-Biosphere Programme (IGBP).
Adina Paytan is a research professor at the Institute of Marine Sciences at the University of California, Santa Cruz. known for research into biogeochemical cycling in the present and the past. She has over 270 scientific publications in journals such as Science, Nature, Proceedings of the National Academy of Sciences, and Geophysical Research Letters.
Amelia E. Shevenell is an American marine geologist who specializes in high-latitude paleoclimatology and paleoceanography. She is currently an Associate Professor in the College of Marine Science at the University of South Florida. She has made notable contributions to understanding the history of the Antarctic ice sheets and published in high-impact journals and, as a result, was awarded full membership of Sigma Xi. She has a long record of participation in international ocean drilling programs and has served in leadership positions of these organizations. Shevenell is the elected Geological Oceanography Council Member for The Oceanography Society (2019-2021).
Sharon Louise Smith is an American marine ecologist known for her work on zooplankton and their ability to respond to climate change. Smith was Professor Emeritus at the Rosenstiel School of Marine and Atmospheric Science at the University of Miami.
Cindy Lee is a retired Distinguished Professor known for her research characterizing the compounds that comprise marine organic matter.
Particulate inorganic carbon (PIC) can be contrasted with dissolved inorganic carbon (DIC), the other form of inorganic carbon found in the ocean. These distinctions are important in chemical oceanography. Particulate inorganic carbon is sometimes called suspended inorganic carbon. In operational terms, it is defined as the inorganic carbon in particulate form that is too large to pass through the filter used to separate dissolved inorganic carbon.
The Great Calcite Belt (GCB) of the Southern Ocean is a region of elevated summertime upper ocean calcite concentration derived from coccolithophores, despite the region being known for its diatom predominance. The overlap of two major phytoplankton groups, coccolithophores and diatoms, in the dynamic frontal systems characteristic of this region provides an ideal setting to study environmental influences on the distribution of different species within these taxonomic groups.
The Martin curve is a power law used by oceanographers to describe the export to the ocean floor of particulate organic carbon (POC). The curve is controlled with two parameters: the reference depth in the water column, and a remineralisation parameter which is a measure of the rate at which the vertical flux of POC attenuates. It is named after the American oceanographer John Martin.
Catherine Jeandel is a French geochemical oceanographer known for her research on isotope geochemistry and trace elements in the ocean.
Kendra Lee Daly is an oceanographer known for her work on zooplankton, particularly in low oxygen regions of the ocean. She is a professor at the University of South Florida, and an elected fellow of the American Association for the Advancement of Science.
Maureen Hatcher Conte is biogeochemist known for her work using particles to define the long-term cycling of chemical compounds in seawater.
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