DISSOLVED ORGANIC-MATTER
; LENA RIVER
; NEARSHORE ZONE
; OLD CARBON
; PEATLANDS
; CLIMATE
; GEOCHEMISTRY
; RADIOCARBON
; PLANKTON
; COASTAL
WOS学科分类:
Multidisciplinary Sciences
WOS研究方向:
Science & Technology - Other Topics
英文摘要:
Climate warming is expected to mobilize northern permafrost and peat organic carbon (PP-C), yet magnitudes and system specifics of even current releases are poorly constrained. While part of the PP-C will degrade at point of thaw to CO2 and CH4 to directly amplify global warming, another part will enter the fluvial network, potentially providing a window to observe large-scale PP-C remobilization patterns. Here, we employ a decade-long, high-temporal resolution record of C-14 in dissolved and particulate organic carbon (DOC and POC, respectively) to deconvolute PP-C release in the large drainage basins of rivers across Siberia: Ob, Yenisey, Lena, and Kolyma. The C-14-constrained estimate of export specifically from PP-C corresponds to only 17 +/- 8% of total fluvial organic carbon and serves as a benchmark for monitoring changes to fluvial PP-C remobilization in a warming Arctic. Whereas DOC was dominated by recent organic carbon and poorly traced PP-C (12 +/- 8%), POC carried a much stronger signature of PP-C (63 +/- 10%) and represents the best window to detect spatial and temporal dynamics of PP-C release. Distinct seasonal patterns suggest that while DOC primarily stems from gradual leaching of surface soils, POC reflects abrupt collapse of deeper deposits. Higher dissolved PP-C export by Ob and Yenisey aligns with discontinuous permafrost that facilitates leaching, whereas higher particulate PP-C export by Lena and Kolyma likely echoes the thermokarst-induced collapse of Pleistocene deposits. Quantitative C-14-based fingerprinting of fluvial organic carbon thus provides an opportunity to elucidate large-scale dynamics of PP-C remobilization in response to Arctic warming.
1.Stockholm Univ, Dept Environm Sci & Analyt Chem, S-10691 Stockholm, Sweden 2.Stockholm Univ, Bolin Ctr Climate Res, S-10691 Stockholm, Sweden 3.Vrije Univ Amsterdam, Dept Earth Sci, NL-1081 HV Amsterdam, Netherlands 4.Stockholm Univ, Dept Phys Geog, S-10691 Stockholm, Sweden 5.Univ Texas Austin, Marine Sci Inst, Port Aransas, TX 78373 USA 6.Yale Sch Forestry & Environm Studies, New Haven, CT 06511 USA
Recommended Citation:
Wild, Birgit,Andersson, August,Broder, Lisa,et al. Rivers across the Siberian Arctic unearth the patterns of carbon release from thawing permafrost[J]. PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA,2019-01-01,116(21):10280-10285