Allochthonous sources and dynamic cycling of ocean dissolved organic carbon revealed by carbon isotopes

Autor: Ann P. McNichol, Prosper K. Zigah, Chiara Santinelli, Li Xu, Daniel J. Repeta, David M. Karl, Carl G. Johnson
Rok vydání: 2017
Předmět:
Zdroj: Geophysical research letters (Online) 44 (2017): 2407–2415. doi:10.1002/2016GL071348
info:cnr-pdr/source/autori:Zigah PK, McNichol AP, Xu L, Johnson C, Santinelli C, Karl D, Repeta DJ/titolo:Allochthonous sources and dynamic cycling of ocean dissolved organic carbon revealed by carbon isotopes/doi:10.1002%2F2016GL071348/rivista:Geophysical research letters (Online)/anno:2017/pagina_da:2407/pagina_a:2415/intervallo_pagine:2407–2415/volume:44
ISSN: 1944-8007
0094-8276
DOI: 10.1002/2016gl071348
Popis: We present concentration and isotopic profiles of total, size, and polarity fractionated dissolved organic carbon (DOC) from Station ALOHA (A Long-term Oligotrophic Habitat Assessment), an oligotrophic site in the North Pacific Ocean. The data show that, between the surface and 3500 m, low molecular weight (LMW) hydrophilic DOC, LMW hydrophobic DOC, and high molecular weight (HMW) DOC constitute 22-33%, 45-52%, and 23-35% of DOC, respectively. LMW hydrophilic DOC is more isotopically depleted (?13C of -23.9? to -31.5? and ?14C of -304? to -795?; mean age of 2850 to 15000 years) than the LMW hydrophobic DOC (?13C of -22? to -23? and ?14C of -270? to -568?; 2470 to 6680 years) and HMW DOC (?13C of ~-21? and ?14C of -24? to -294?; 135-2700 years). Our analyses suggest that a large fraction of DOC may be derived from allochthonous sources such as terrestrial and hydrothermal DOC and cycle on much longer time scales of >10000 years or enter the ocean as preaged carbon
Databáze: OpenAIRE
Externí odkaz: