The Arctic Ocean is our climate’s ‘canary in the coal mine’. Some of the most dramatic changes in temperature and ocean conditions are being observed here. Although quantifying and characterizing how the marine carbon cycle is changing in this remote, semi-ice covered basin is challenging, we are currently working to better constrain particulate carbon export in the Western Arctic Ocean using short-lived isotopes of thorium (234Th,228Th).
Deck operations for the U.S. GEOTRACES program begin in the central Arctic on the USCGC Healy (photo: Cory J. Mendenhall)
Coastal particle dynamics and carbon storage
Coastal zones provide ecosystem services, which support our communities and our oceans. While coastal export and the storage of carbon are important pieces in the marine carbon budget, these regions of the ocean are dynamic and difficult to predict. We have ongoing collaborative work looking at carbon and nutrient cycling in the Bedford Basin, Nova Scotia and the Gulf of Maine.
Sediments from Bedford Basin were analyzed for C, N, Th, and Pb isotopes to help ‘balance’ the budget
Quantifying dust flux to the world’s oceans
In this ongoing work through the U.S. GEOTRACES program, long-lived isotopes of thorium (230Th,232Th) are used to track the amount of dust entering the surface ocean, as well as the remnant signal of prior dust events that resides in the underlying 1000s of meters of water.
Dr. Black processes Pacific seawater in the Anderson cleanroom at Lamont-Doherty Earth Observatory
A better understanding of the marine Fe cycle
The cycling of trace elements can influence (and be influenced by) the processes that constitute the ocean’s biological carbon pump.We strive to better understand how the supply, loss, residence time, and recycling of elements, such as iron, can impact surface communities and ocean productivity.
Dr. Black helps recover large volume pumps collecting particles for trace metal analyses at station ALOHA
Future Great Lakes projects
The Great Lakes contain over 80% of North America’s surface freshwater and 20% of the world’s supply (USEPA). Unfortunately, human actions have added contaminants like Hg, microplastics, and fire retardants to these valuable sources of drinking water,transportation, recreation, and power. These contaminants are global issues facing freshwater and marine systems alike.With our future work we hope to investigate how these types of pollutants are transported through the water column to the sediments via the sinking of biological particulate matter.We are actively looking for local collaborations and interested parties.
Lake Ontario (far right) is located just 10 miles from the UR campus(image: National Geographic)
Advancements in radionuclide measurements
One of the long term goals of the TRACER lab is to push the frontier of autonomous radionuclide measurements, which includes developing more precise and practical sensors for in-situ quantification of marine and freshwater radioactivity. The TRACER lab will have the full range of traditional radiochemical instrumentation with which to calibrate new equipment and the Genesee River and Lake Ontario are ideal, local test sites. We hope to forge collaborations with scientists, engineers, and industry leaders to utilize and improve these in-situ detectors for contamination monitoring and process-based studies.
The typical CTD rosette package collects seawater samples for shipboard analyses and in-situ oxygen, fluorescence, salinity, and transmissometry datausing mounted sensors(photo: Cory J. Mendenhall)
