"This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5)."
The use of stable isotopes in biogenic calcium carbonate shells is a standard tool in paleoclimate studies. However, there are still outstanding issues that need to be addressed before this tool can be utilized to its full potential. Researchers at the University of Hawaii will study (1) the effects of carbonic anhydrase (CA) on the rate of oxygen (O) isotope equilibration between the dissolved inorganic carbon (DIC) species and water and (2) the effects of magnesium ions on the O isotope equilibrium between DIC-species and water. The effects of these processes will be determined using quantitative (rapid) and slow inorganic carbonate precipitation experiments.
The two potential effects on oxygen isotopes that will be studied in this project are important to discern because they represent fundamental biological or chemical processes or occurrences within the marine setting. The possible influence of carbonic anhydrase is important because it plays an important role in a variety of essential processes whereas the influence of magnesium ions represents an important parameter in characterizing ocean water chemistry and its influence on chemical equilibrium.
Broader Impacts: This study will contribute to the improved understanding of a tool commonly employed in paleo-climatology - oxygen isotopes in carbonate microfossils. The anticipated outcome will be an improved separation of past climate signals from undesirable biases. This separation would effectively lead to a better understanding of Earth's climate history. An additional goal of the project is to foster education of students at different levels. This study was designed in part by a graduate student who also assisted in the preparation of the project proposal.
