Award: OCE-1756103

This project was conceived to answer fundamental questions about the chemical nature of mineral dust and particles from human emissions that are transported over the North Pacific Ocean. We also sought to estimate the rate at which this material enters the surface ocean. A key question was the significance of this deposition to the distributions of trace elements. Answering that question requires assessing the amount of respective trace elements which are able to dissolve into seawater from the particles. We collected 23 bulk aerosol samples and 11 size-fractionated aerosol samples during the course of the research cruise from the waters off of Alaska to Tahiti. These samples were analyzed for their chemical composition, fractional solubility, and deposition rate. The cruise happened during the low-dust season in the North Pacific. As a result, the observed concentrations were low in comparison to those in other regions of the world and in this region during other times of the year. The resulting data provides a low-bound constraint on deposition estimates. Several peer-reviewed journal articles have been written and many conference presentations given during the project period. The collections made during this project provided a set of subsamples which have been shared with other members of the research community. As a result, additional works have been submitted and published. This synergy with other researchers greatly expands the value of the project. Additionally, this project has served as extensive training for a graduate student and postdoctoral researcher. The graduate student analyzed samples to characterize the concentrations of water-soluble anions and cations and that work served as the basis of their thesis. The postdoctoral researcher sailed on part of the cruise and analyzed a large portion of the collected samples. He was the primary author of two manuscripts arising from this work. Data from this project is shared on a publicly available site for other researchers to access. In addition, the PI uses data, photos, and anecdotes from this project in his courses taught at the University of Georgia. Last Modified: 05/19/2022 Submitted by: Clifton Buck