Lipid biomarker data in sediment core from Chukchi Sea

The Chukchi Sea, one of the largest shelf seas, plays an important role in biogeochemical cycle and climate change in high latitude North Hemisphere. Here we examined a variety of lipid biomarkers in a sediment core (ARC-R09) collected from central Chukchi Sea to reconstruct paleoenvironmental evolution during the past 8700 years. The sea-ice biomarker IP25 (0.4–5.0 ng g-1 dws) and derived PIP25 indicator (0.04–0.86) suggested extended sea ice cover in early (8.7–8.3 cal kyr BP) and late (1.0–0 cal kyr BP) compared to middle to late Holocene (8.0–1.0 cal kyr BP). In contrast, the open-water phytoplankton biomarkers (i.e., dinosterol) and terrestrial biomarkers (long-chain n-alkanes) reached the highest abundance during 8.0–5.5 cal kyr BP, suggesting the higher marine primary productivity and larger terrestrial OC input in middle Holocene. The TEX86 indicative of sea surface temperature (SST; -3.0 to 3.4 ℃) and the BIT index (0.1–0.33) indicative of relative abundance of terrestrial vs. marine OC generally declined from early to middle Holocene, however, the TEX86-SST rapidly increased at 3.5 cal kyr BP, and stayed at the relatively high level until 2.0 cal kyr BP, followed by a large amplitude variability, whereas the BIT index remained at the low level (< 0.2) until present. Overall, the complex biomarker patterns were attributed to Holocene variability in solar insolation, inflow of warm and nutrient rich Pacific water, sea level and ocean circulation in the Chukchi Ses