USAP-DC

The Amundsen Sea hosts the most productive polynya in all of Antarctica, with its vibrant green waters visible from space, and an atmospheric CO2 uptake density 10x higher than the Southern Ocean average. The region is vulnerable to climate change, experiencing rapid losses in sea ice, a changing icescape, and some of the fastest melting glaciers flowing from the West Antarctic Ice Sheet (WAIS). ARTEMIS aims to characterize the climate-sensitive nature of glacial meltwater-driven micronutrient (iron, Fe) contributions driving ecosystem productivity and CO2 uptake in the coastal Antarctic. We propose to integrate observations and ocean modeling of these processes to enhance predictive capabilities. Currently, basal melt resulting from warm deep waters penetrating ice shelf cavities dominates mass losses of WAIS, contributing to sea level rise. These physical melting processes are being studied by the International Thwaites Glacier Collaboration (ITGC). The impact of melting on the marine ecosystem has also been explored, and we know that productivity is due in part to Fe-rich, glacial meltwater-driven outflow. The biogeochemical composition of the outflow from the glaciers surrounding the Amundsen Sea is largely unstudied, however. Improved knowledge would provide keys to understanding meltwater's future impact on the ecosystem. An ongoing field program (TARSAN, part of the ITGC) offers the ideal physical oceanographic framework for our biogeochemical effort. We propose here to collaborate with TARSAN-supported UK scientists, providing value added to both team efforts. ARTEMIS will add shipboard measurements (trace metals, carbonate system, nutrients, organic matter, microorganisms) and biogeochemical sensors on autonomous vehicles to gather critical knowledge needed to understand the impact of the melting WAIS on both the coastal ecosystem and the regional carbon (C) cycle. Driving questions include: 1) what are the fluxes and chemical forms of Fe, C, and microorganisms in the ice shelf outflow? 2) what are the relative contributions to the ouflow from deep water, benthic, and glacial melt sources, and how do these inputs combine to affect the bioavailability of Fe? 3) How are Fe and C compounds modified as the outflow advects along the coastal current and mixes into the bloom region? and 4) what will be the effect of increased glacial melting, changes in the coastal icescape, and declining sea ice on theecosystem of the Amundsen Sea? Such questions fall outside the focus of the ITGC, but are of keen interest to Antarctic Organisms and Ecosystems and Antarctic Integrated System Science programs.

Person	Role
Yager, Patricia	Investigator and contact
Medeiros, Patricia	Co-Investigator
Sherrell, Robert	Co-Investigator
St-Laurent, Pierre	Co-Investigator
Fitzsimmons, Jessica	Co-Investigator
Stammerjohn, Sharon	Co-Investigator
Oliver, Hilde	Researcher
Herbert, Lisa	Researcher

Antarctic Organisms and Ecosystems	Award # 1941483
Antarctic Organisms and Ecosystems	Award # 1941327
Antarctic Organisms and Ecosystems	Award # 1941308
Antarctic Organisms and Ecosystems	Award # 1941304
Antarctic Organisms and Ecosystems	Award # 1941292

USAP-1941483_1

Deployment	Type
NB Palmer	ship expedition

DataManagementPlan_ARTEMIS.pdf

Repository	Title (link)	Format(s)	Status
R2R	Expedition Data of NBP2202	Not Provided	pending
William & Mary ScholarWorks	Dataset: A numerical simulation of the ocean, sea ice and ice shelves in the Amundsen Sea (Antarctica) over the period 2006-2022 and its associated code and input files	netCDF	exists
SEANOE	Numerical experiments examining the response of onshore oceanic heat supply to yearly changes in the Amundsen Sea icescape (Antarctica)	netCDF	exists
USAP-DC	Vertical ocean profiles collected by a Conductivity-Temperature-Depth (CTD) package in the Amundsen Sea	ZIP Archive	exists

1. Jacob, B., Queste, B. Y., & du Plessis, M. D. (2024). Turbulent heat flux dynamics along the Dotson and Getz ice-shelf fronts (Amundsen Sea, Antarctica). (doi:10.5194/egusphere-2024-2076)