East Siberian Sea: Interannual heterogeneity of the suspended particulate matter and its biogeochemical signature

The East Siberian Sea (ESS) is the largest, shallowest and most icebound Arctic marginal sea. It receives substantial input of terrigenous material climate-vulnerable old organic carbon from both coastal erosion rivers draining extensive permafrost-covered watersheds. This study focuses on interannual variability spatial distribution suspended particulate matter (SPM) in surface bottom waters ESS during ice-free period 2000, 2003, 2004, 2005 2008. We report composition (POC), total nitrogen (TN), POC/TN ratios, isotopes (?13C, ?15N) provide estimates contribution terrestrial (terrOC) based ?13C isotopic values. results show that SPM elemental-isotopic characteristics POC differ significantly between western biogeochemical province (WBP; West 165oE) eastern (EBP; ESS. mean concentration WBP almost an order magnitude higher than EBP. From west-to-east ESS, tends to become more depleted ?15N, while becomes isotopically heavier. trend can be explained by a shift sources origin (erosion ice complex riverine POC) becoming dominantly marine plankton. maximum terrOC reached 99% parts WBP, but accounts for as low 1% At same time, type atmospheric circulation its associated regime water transport control displacement semi-stable border EBP east or west if compared long-term average position near 165oE. Our multi-year investigation provides robust observational basis better understanding fate upon entering shelf waters. also deeper insights into interaction land-shelf sea system largest World Ocean, Shelf system.