Dissolved organic carbon investigations from the Kara Sea, supplement to: Köhler, Hayo; Meon, B; Gordeev, Viacheslav V; Spitzy, Alejandro; Amon, Rainer M W (2003): Dissolved organic matter (DOM) in the estuaries of Ob and Yenisei and the adjacent Kara Sea, Russia. In: Stein, R; Fahl, K; Fütterer, D K; Galimov, E M & Stepanets, O V (eds.), Siberian River Run-off in the Kara Sea: Characterisation, Quantification, Variability, and Environmental Significance, 488 pp. Proceedings in Marine Sciences, Elsevier, Amsterdam, 6, 281-308

Based on observations during four scientific expeditions to the Kara Sea and the Siberian rivers Ob and Yenisei we determined the discharge, distribution and characteristics of dissolved organic matter (DOM). Surface concentrations of dissolved organic carbon (DOC) ranged from 151 IlM C in the northern Kara Sea to 939 IlM C in the river Ob. The estimated annual mean DOC concentration in the Yenisei (681 IlM C) was slightly higher than in the Ob (640 IlM C). Dissolved organic nitrogen (DON) concentrations typically varied between 5 and 15 IlM N with higher values in the rivers. Freshwater discharge and DOC concentrations experienced pronounced seasonal variations strongly affecting the spatial and temporal distribution of DOM in the Kara Sea. The largely conservative distribution of DOC and DON along the salinity gradient indicated the predominantly refractory character of riverine DOM. This observation was consistent with laboratory experiments, which showed only minor losses due to flocculation processes and bacterial consumption. Optical properties and relatively high C/N ratios (19 to 51) of DO M suggest that a large fraction of river DOM is of terrestrial origin and that phytoplankton contributed little to DOM on the Kara Sea shelf during the sampling periods. Together, the rivers Ob and Yenisei discharge about 8 Tg DOC yr- I into the Kara Sea. Due to the absence of efficient removal mechanisms in these estuaries the majority of riverine DOM appears to pass the estuarine mixing zone and is transported towards the Arctic Ocean.

DOI https://doi.org/10.1594/PANGAEA.736640
PID http://hdl.handle.net/10013/epic.15588.d001
Metadata Access https://ws.pangaea.de/oai/provider?verb=GetRecord&metadataPrefix=datacite4&identifier=oai:pangaea.de:doi:10.1594/PANGAEA.736640
Creator Köhler, Hayo; Meon, B; Gordeev, Viacheslav V; Spitzy, Alejandro; Amon, Rainer M W
Publisher PANGAEA - Data Publisher for Earth & Environmental Science
Publication Year 2010
Rights Creative Commons Attribution 3.0 Unported
OpenAccess true
Language English
Resource Type Supplementary Collection of Datasets
Format application/zip
Size 5 datasets
Discipline Earth System Research
Spatial Coverage (58.389W, 69.981S, 85.763E, 77.900N); Kara Sea
Temporal Coverage Begin 1997-09-13T09:08:00Z
Temporal Coverage End 2000-09-20T19:58:00Z