Award: OCE-1756104

This Project Outcomes Report duplicates some of the Project Outcomes Report posted for NSF-1756103 (PI Clifton Buck at UGA-Skidaway Institute of Oceanography-SkIO) because this was a collaborative research project. PI William Landing at FSU was funded primarily to provide the aerosol and rainfall sampling equipment and shipping logistics for the research cruise while all of the sample analyses were conducted by colleagues at SkIO. PI Landing worked closely with colleagues at SkIO in the data interpretation and writing of journal articles and in conference presentations. This project was conceived to answer fundamental questions about the chemical nature of mineral dust and particles from human emissions that are transported and deposited 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 concentrations and distribution patterns of biologically-essential trace elements such as manganese, iron, cobalt, nickel and copper. Addressing that question requires measuring the fraction of each trace element that can dissolve into seawater from the particles. We collected 23 bulk aerosol samples and 11 size-fractionated aerosol samples during 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 and included PI Landing and PI Buck as co-authors. The collections made during this project provided a set of aerosol 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 at SkIO. 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, PI Clifton Buck at SkIO uses data, photos, and anecdotes from this project in his courses taught at the University of Georgia. Last Modified: 03/25/2024 Submitted by: WilliamMLanding