Particulate organic matter (POM) of samples from the Lena River delta ...

• Main Authors: Winterfeld, Maria, Laepple, Thomas, Mollenhauer, Gesine
• Format: Article in Journal/Newspaper
• Language: English
• Published: PANGAEA 2015
• Subjects: Permafrost Research Periglacial Dynamics @ AWI AWI_PerDyn; laptev; Laptev Sea; lena delta; lena river; permafrost; Phytoplankton; Siberia
• Online Access: https://dx.doi.org/10.1594/pangaea.855439; https://doi.pangaea.de/10.1594/PANGAEA.855439

Particulate organic matter (POM) derived from permafrost soils and transported by the Lena River represents a quantitatively important terrestrial carbon pool exported to Laptev Sea sediments (next to POM derived from coastal erosion). Its fate in a future warming Arctic, i.e., its remobilization and remineralization after permafrost thawing as well as its transport pathways to and sequestration in marine sediments, is currently under debate. We present one of the first radiocarbon (14C) data sets for surface water POM within the Lena Delta sampled in the summers of 2009 - 2010 and spring 2011 (n = 30 samples). The bulk D14C values varied from -55 to -391 per mil translating into 14C ages of 395 to 3920 years BP. We further estimated the fraction of soil-derived POM to our samples based on (1) particulate organic carbon to particulate nitrogen ratios (POC : PN) and (2) on the stable carbon isotope (d13C) composition of our samples. Assuming that this phytoplankton POM has a modern 14C concentration, we ... : Supplement to: Winterfeld, Maria; Laepple, Thomas; Mollenhauer, Gesine (2015): Characterization of particulate organic matter in the Lena River delta and adjacent nearshore zone, NE Siberia - Part I: Radiocarbon inventories. Biogeosciences, 12(12), 3769-3788 ...