The Arctic Ocean (AO) is of great importance for climate regulation and carbon sequestration, contributing 5–14% to the global balance of CO2 sinks and sources. It is surrounded by land, with limited exchanges with its adjacent basins, the Atlantic (through the Fram Strait and Canadian Arctic Archipelago) and Pacific (through the Bering Strait) Oceans and great part of the Arctic outflow is exported through the Fram Strait. It is a unique ocean basin compared to the others, given the high loads of freshwater and dissolved organic matter (DOM) supplied by the Arctic Rivers. DOM is a large active Arctic organic carbon reservoir representing more than 95% of the organic carbon in the water and encompasses a wide range of compounds with variable molecular complexity, whose relative contribution varies in different environments, depending on its origin.
The Arctic environment is experiencing the brunt of global warming with the largest regional increases in atmospheric temperature (two- or three-fold the global average rate). This implies drastic reductions in summer sea-ice extent and enhanced glacier and ice sheet melt and permafrost thaw. This, in turn, leads to changes in freshwater export, production of DOM in river catchments and riverine transport of organic material into the Arctic seas. Studies on DOM in the region are needed for establishing current conditions and documenting coming changes propagating from river basins to the Arctic Ocean. However, given their difficult access, it is imperative to develop equipment and techniques for autonomously monitoring DOM in the remote Arctic Seas to accurately determine the fate and impact of mobilized carbon.
CarbEx employs spectroscopy measurements (e.g. absorption and fluorescence) and chemometrical data analysis combined to numerical modeling to assess and characterize the export of freshwater and dissolved organic matter (in terms of dissolved organic carbon–DOC) from the Arctic to the Atlantic Ocean through the Fram Strait.
The major findings (so far) of the project are that we can use FDOM to distinguish freshwater originated from the Eurasian and Canadian basins. We have also developed two methods within the project: one algorithm to estimate DOC concentrations from CDOM spectral properties and one method to estimate Arctic DOC export from moored platforms in the East Greenland Current. Project participants have also taken part in two reports with recommendations for Arctic research and sustainability in the context of the UN Ocean Decade for Sustainable Development and the European Polar Science Week. The project has also focused on communication, and we have submitted a manuscript for publication in Frontiers for Young Minds, where we aim to attract students to the field of marine sciences.
