Stable isotopes of carbon (δ13C-DIC) and oxygen (δ18O-H2O) in the western Arctic Ocean (2021)

Stable isotopes of carbon (δ13C-DIC) and oxygen (δ18O-H2O) are two essential tracers that help understand the changing Arctic water masses and carbon cycles. However, the interplay of physical, chemical, and biological factors and their influence on δ13C-DIC in the Arctic Ocean are poorly understood. Therefore, we investigated the distributions of δ13C-DIC and δ18O-H2O in the western Arctic Ocean during the Mirai 2021 cruise from September 12th to October 2nd under the framework of the Arctic Challenge for Sustainability II Project (ArCS II). Here we present the dataset of δ13C-DIC and δ18O-H2O, which covers the central and eastern Chukchi Sea, extending from the Bering Strait to the southwestern Canada Basin. Combined with other hydrographic and biogeochemical parameters, δ18O-H2O samples could be used to decipher and quantify the contributions of source water masses in each sample. δ13C-DIC samples could be helpful to better understand the carbon export pathways and partition of potential carbon sources. The observations of δ18O-H2O and δ13C-DIC facilitate a better understanding of the carbon flows, exports, and degradation from highly productive shelves to oligotrophic basins, and thus a better prediction of future changes in the Arctic carbon dynamics.