Award: OCE-1559004

Project Outcomes Report OCE 1559004 Collaborative Research: CaCO3 dissolution in the N Pacific Ocean: Comparison of Lab and Field Rates with Biogenic and Abiogenic Carbonates As CO2 levels in the atmosphere continue to rise, a portion of this CO2 dissolves in the ocean. As this happens, the ocean becomes more acidic. Like taking a TUMS, the naturally occurring CaCO3 in the upper ocean, part of the ocean ecosystem, will sink into acidic deeper waters and neutralize some of this acid. Our work documents how fast this can occur. It happens very slowly, the natural dissolution process is actually controlled by three different ?accelerators?. In most water, the rate of dissolution is slow because the acceleration mechanism is a slow mechanism. We discovered where the acceleration mechanism changes to a much faster mechanism, and we mapped out the North Pacific Ocean to show where CaCO3 will start to dissolve much faster. We are learning about dissolution rate and mechanism to understand how fast and what it will take to neutralize the extra CO2 that?s entering the ocean. To conduct this research we made measurements in the lab and we built new devices to make these measurements at sea, while on a ship. While on this research cruise, we also investigated the amount and type of particles of CaCO3 that were floating around. We surveyed particle distributions from the top of the ocean down to the bottom. We also measured the chemistry of the ocean, like taking one?s temperature, determining very small changes that have occurred over time. CaCO3 comes in various types and sizes so we had to conduct experiments with different variables to take this into account. We assessed dissolution of the two major types of CaCO3 (calcite and aragonite), we assessed dissolution as a function of temperature, ionic composition of the sea water and organic content of the sea water. We also assessed dissolution rates of natural CaCO3, the minerals formed by living organisms such as coccolithophores and foraminifera. To showcase our work to the general public, we brought a film maker and a graphic artist on board our research cruise. They documented our work, in very funny ways, and produced short films and graphics. The film was displayed at the Natural History Museum in Los Angeles to show the public about how scientific funding is utilized. Last Modified: 07/29/2020 Submitted by: William M Berelson