Western Greenland ice sheet-land-ocean interactions: near-shore dissolved organic carbon 14C ages and composition in eastern Baffin Bay, 2021

This dataset was generated to improve understanding of how freshwater inputs from the Greenland and surrounding terrestrial systems influence dissolved organic carbon (DOC) dynamics in coastal waters in western Greenland. Water samples were collected from September 14 to October 1, 2021, during a cruise aboard the US Coast Guard Cutter Healy along a latitudinal transect off western Greenland, spanning Nuuk to the Uummannaq Fjord. At 12 stations, seawater was sampled at 5 and 50 meters depth for biogeochemical and isotopic analysis. The dataset includes measurements of DOC concentration and composition, radiocarbon (¹⁴C) and stable carbon isotopes (¹³C) of DOC, stable oxygen isotopes (δ¹⁸O), salinity, water temperature, and molecular signatures of DOC. DOC composition was resolved into classes such as aliphatic, lignin, unsaturated high-oxygen (UHO), and others using ultra-high performance liquid chromatography coupled with high-resolution mass spectrometry (UHPLC-HRMS). Radiocarbon measurements were conducted using accelerator mass spectrometry (AMS). The resulting dataset offers insights into the spatial variability of DOC age and sources across glaciated and non-glaciated regions of Greenland and serves as a reference for future studies on Arctic carbon cycling under ongoing climate change.