We explore the chemistry of elements which are present in seawater at extraordinarily minute concentrations. Termed “trace elements,” they are present in ocean water at concentrations of parts per billion or parts per trillion. Despite these tiny amounts, trace elements can control the distribution of life in the surface ocean.
Phytoplankton, microscopic plant-like organisms that use sunlight for photosynthesis, are the basis of the marine food chain. In addition to sunlight and macronutrients like nitrate and silicate, phytoplankton metabolism requires trace elements to function properly. Thus, primary production can be limited by trace elements in vast areas of the ocean because their small concentrations are unable to meet the biological demand.
We ask fundamental questions about marine trace element chemistry. What are the sources and sinks of trace elements? What are the input and removal rates? We collect samples from around the world and characterize the chemistry of seawater, precipitation, groundwater, marine particles, and aerosol particles.
Our group and department values the contributions of all and endeavors to foster an inclusive environment. Learn more about Diversity and Inclusion initiatives here: https://www.marsci.uga.edu/diversity-inclusivity
Dr. Chris Marsay is a researcher with a long record of experience in the field and laboratory. Our work with the US GEOTRACES program took him to the North Pole in Fall 2015. Thus far, he has led two papers describing Arctic aerosols and melt ponds.
In 2018, he completed the second leg of the GEOTRACES GP15 section from Hawaii to Tahiti.
He returned to the Arctic in early 2020 as part of the MOSAiC expedition studying the impacts of climate change.
Devon Umstead joined the group in Fall 2019 as a Masters student. He has been analyzing aerosol samples from the North Pacific to learn how aerosol fractional solubility may be linked to the presence of acidic compounds in the atmosphere. Devon presented preliminary results at the 2020 Southeastern Biogeochemistry Symposium and is preparing a more comprehensive presentation for the 2022 Ocean Sciences Meeting.
Charlotte Kollman came to SkIO as a new PhD student in Fall 2020. She is working on the Hawaii Aerosol Time Series project.
Dr. Althea Moore joined our team in May 2021. A marine ecologist by training, she is working on our project studying the impacts of terrestrial epiphytes on rainfall chemistry.
Current Research Projects
Dr. Buck is the principal investigator of the National Science Foundation funded project US GEOTRACES PMT: Quantification of Atmospheric Deposition and Trace Element Fractional Solubility. The 2018 U.S. GEOTRACES Pacific Meridional Transect (GP15) crossed the North Pacific basin from the dusty northern hemisphere to the pristine and oligotrophic south. Quantifying the atmospheric fluxes of trace elements to the ocean is an essential component of the GEOTRACES mission and no study in this region has combined atmospheric sample collections with multi-element, high-resolution sampling of the upper ocean. We will also be conducting dissolution experiments to explore the mechanisms which control aerosol solubility and bioavailability.
The National Science Foundation has also funded our participation in the The Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) project. Dr. Marsay joined a group of scientists from around the world aboard the RV Polarstern collecting samples of atmospheric deposition to better understand this important transport pathway in the planet’s most rapidly changing environment. The ship spent 2020 frozen in the Arctic sea ice and serving as a floating observatory.
Read more about Dr. Marsay’s experiences in the ice:
The Hawaii Aerosol Time-Series (HATS) is a four-year project designed to link changes in aerosol chemistry and deposition with marine particle chemistry in the upper ocean. Our plan includes two years of aerosol sampling at the Makai Research Pier and cruises to Station Aloha to collect particle samples from the water column. The cruises will run in conjunction with the Hawaii Ocean Time-Series program.
This research is supported by NSF award 1949660.
We discussed the project in this profile: Aerosol Dust and Ocean Chemistry
We also work on land. NSF has recently supported our study (1954322) of changes to solute chemistry as rainfall travels through tree canopies. We are working with partners at Georgia Southern University and Franklin & Marshall College. Dr. Moore is leading the field work and chemical analyses associated with this project.
Past Research Projects
We welcomes collaborators from around the world who wish to take advantage of our resources. In 2017, we welcomed Dr. Sylvia Falco from Valencia, Spain. Dr. Falco specializes in coastal and estuarine water quality issues. We also hosted two graduate students from Rio Grande, Brazil. Ms. Cacinele Rocha and Ms. Mariele Paiva have spent several months learning techniques for collecting and analyzing environmental samples for trace elements. The data they have produced will be incorporated into their respective theses.
We have a long running collaboration with the international GEOTRACES program which is a study of the biogeochemical cycles of trace elements and their isotopes. GEOTRACES has greatly increased the number of trace element observations from around the world and data is viewable at the eGEOTRACES electronic atlas. The Buck Lab has participated in three research cruises, US GEOTRACES GP16, GN01, and GP15 which were supported by the National Science Foundation.