A large portion of carbon is stored in minerals that were formed by marine organisms over millions of years. Some plankton (marine organisms that drift at the surface of the ocean) form tiny shells made of calcium carbonate, the same mineral in beach shells and limestone riverbeds. Once the organisms die, the shells slowly sink along with bits of other types of plankton. Some of the shells dissolve as they fall deeper into the ocean, shifting the distribution of carbon dioxide and its related forms in the ocean.
I am interested in quantifying the amount of carbon dioxide transferred due to calcium carbonate formation and dissolution, where in the water column this dissolution occurs, and the mechanisms of dissolution within the water column. I am particularly interested in the coastal systems, where time scales of circulating deep water are generally shorter and biological productivity is often greater. Since calcium is the other half of calcium carbonate, I have been developing a lab-based measurement to analyze calcium in the seawater samples I have collected along the San Diego coast and on this CLIVAR/CO2 cruise.
John measuring pH - another part of the carbon system
In the future, I plan to apply this calcium measurement to study the formation and dissolution of calcium carbonate in other ecosystems around the world including coral reefs (corals skeletons are calcium carbonate) and rivers (dominant source of most salts to the ocean, including calcium). I am also working on a separation technique and sensor for seawater that can be tuned to measure calcium among other chemicals in the ocean.
I think the science is pretty cool on its own, but traveling and living by the ocean (Scripps Institution of Oceanography - San Diego, CA) are definite perks to the job. Although, I don’t think of it as a job, it’s just part of my life : )
by John Ballard
No comments:
Post a Comment