HBI concentrations and classification tree model predictions of sea ice conditions for surface sediments and downcore records in the Barents Sea

We investigated the potential for classification tree (CT) models to provide a further approach to paleo Arctic sea ice reconstruction through analysis of a suite of six highly branched isoprenoid (HBI) biomarkers in 198 surface sediments from the Barents Sea. The four CT models representing modern sea ice conditions were then applied to four downcore records within the study area (cores BASICC 1, 8, 43, and core MSM5/5-712-1) in order to reconstruct sea ice conditions over the last 300 years. The current dataset includes the absolute HBI concentrations in all sediment samples (ng/g dry sed.), as well as CT model outcomes for all samples, which were classified as having experienced marginal, intermediate, or extensive overlying sea ice cover (further details are available in the manuscript associated with these data).