Multi-element Oceanic and Atmospheric Summer Isoscape of the Canadian Arctic Archipelago and Implications for Biogeochemical Cycling

Rising greenhouse gas concentrations as a result of human activities, combined with declining sea ice and increasing temperatures, have a large potential to alter carbon cycling and ecosystem structure in the Arctic Ocean. Carbon dioxide and methane are of great interest, as the sources and fluxes between the ocean, atmosphere, land, and cryosphere are important components of the climate system. While the Arctic Ocean has been a research focus in recent years, the Canadian Arctic Archipelago (CAA), a significant portion of the Northwest Passage, and a principal conduit of Arctic Ocean water from the Pacific Ocean to the North Atlantic has been relatively understudied due to harsh weather conditions and presence of year-round ice coverage. This presentation will discuss isotope data collected on the 2019 Northwest Passage Project expedition aboard the Swedish Icebreaker RVIB Oden in the CAA. Isotope values were analyzed from suspended particulate matter, seawater, and continuous atmospheric collections along the cruise track. The concentrations of these variables, in addition to water column macronutrients and dissolved organic carbon, were used to interpret the contributions from and interactions between the ocean, cryosphere, land, and meteoric exports. Due in part to the heterogeneous geography of the region, spatial variability was observed in the aforementioned variables and their isotopic signatures. The Arctic, due its ice cover, is a crucial region for future positive feedbacks on climate change, and is soon to receive greater human impacts as reduced ice cover renders the region more accessible. These observations will provide a baseline of source, sink, and inventory data for future remote sensing validations and for biogeochemical and freshwater budgets in this important region.