English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Fluvial discharge and coastal erosion of the permafrost-dominated East\udSiberian Arctic delivers large quantities of terrigenous organic carbon\ud(Terr-OC) to marine waters. The composition and fate of the remobilized\udTerr-OC needs to be better constrained as it impacts the potential for a\udclimate–carbon feedback. In the present study, the bulk isotope (δ13C and Δ14C) and macromolecular (lignin-derived phenols)\udcomposition of the cross-shelf exported organic carbon (OC) in different\udmarine pools is evaluated. For this purpose, as part of the SWERUS-C3\udexpedition (July–September 2014), sediment organic carbon (SOC) as well as\udwater column (from surface and near-bottom seawater) dissolved organic\udcarbon (DOC) and particulate organic carbon (POC) samples were collected\udalong the outer shelves of the Kara Sea, Laptev Sea and East Siberian Sea.\udThe results show that the Lena River and the DOC may have a preferential\udrole in the transport of Terr-OC to the outer shelf. DOC concentrations\ud(740–3600 µg L−1) were 1 order of magnitude higher than POC (20–360 µg L−1),\udwith higher concentrations towards the Lena River plume. The\udδ13C signatures in the three carbon pools varied from\ud−23.9 ± 1.9 ‰ in the SOC, −26.1 ± 1.2 ‰ in the DOC and −27.1 ± 1.9 ‰\udin the POC. The Δ14C values ranged\udbetween −395 ± 83 (SOC), −226 ± 92 (DOC) and −113 ± 122 ‰\ud(POC). These stable and radiocarbon isotopes were also different between the\udLaptev Sea and the East Siberian Sea. Both DOC and POC showed a depleted and\udyounger trend off the Lena River plume. Further, the Pacific inflow and the\udsea-ice coverage, which works as a barrier preventing the input of “young”\udDOC and POC, seem to have a strong influence in these carbon pools,\udpresenting older and more enriched δ13C signatures under the\udsea-ice extent. Lignin phenols exhibited higher OC-normalized concentrations\udin the SOC (0.10–2.34 mg g−1 OC) and DOC (0.08–2.40 mg g−1 OC) than in the POC\ud(0.03–1.14 mg g−1 OC). The good relationship between lignin and Δ14C signatures in the DOC suggests that a significant fraction of the\udouter-shelf DOC comes from “young” Terr-OC. By contrast, the slightly\udnegative correlation between lignin phenols and Δ14C signatures\udin POC, with higher lignin concentrations in older POC from near-bottom\udwaters, may reflect the off-shelf transport of OC from remobilized\udpermafrost in the nepheloid layer. Syringyl ∕ vanillyl and cinnamyl ∕ vannillyl\udphenol ratios presented distinct clustering between DOC, POC and SOC,\udimplying that those pools may be carrying different Terr-OC of partially\uddifferent origin. Moreover, 3,5-dihydroxybenzoic acid to vanillyl phenol\udratios and p-coumaric acid to ferulic acid ratios, used as a diagenetic\udindicators, enhanced in POC and SOC, suggesting more degradation within\udthese pools. Overall, the key contrast between enhanced lignin yields both\udin the youngest DOC and the oldest POC samples reflects a significant\uddecoupling of terrestrial OC sources and pathways

biogeosciences

Contrasting composition of terrigenous organic matter in the dissolved, particulate and sedimentary organic carbon pools on the outer East Siberian Arctic Shelf