Physical controls on dissolved inorganic radiocarbon variability in the California Current

TitlePhysical controls on dissolved inorganic radiocarbon variability in the California Current
Publication TypeJournal Article
Year of Publication1998
AuthorsMasiello, CA, Druffel, ERM, Bauer, JE
JournalDeep-Sea Research Part Ii-Topical Studies in Oceanography
Volume45
Issue4-5
Pagination617-642
ISSN0967-0645
Accession NumberWOS:000074941900004
Abstract

We present depth profiles of Delta(14)C and delta(13)C Of dissolved inorganic carbon (DIC) at Station M in the Eastern North Pacific. Several seasonal profiles are presented for the time period between 1991 and 1996. Comparison with GEOSECS data clearly shows changes in ocean radiocarbon profiles since 1973. The Delta(14)C Of DIC shows the most variability at depths of 450, 85, and 25 m, and the lowest variability at depths of 1600 and 2500 m. The largest variability in DIC Delta(14)C occurs at 450 m, a depth marked by large fluctuations in the radiocarbon signatures of the source waters. The likely controls of DIC Delta(14)C variability are physical changes in the circulation of the California Current System. A simple two-box model is used to show the importance of wind driven mixing at the surface. We discuss the likely effects of mesoscale eddies and ENSO on the DIC Delta(14)C values at this site. We also show that remineralization of organic carbon (dissolved or particulate) is not responsible for the variability in the Delta(14)C Of DIC observed at Station M. (C) 1998 Elsevier Science Ltd. All rights reserved.

DOI10.1016/S0967-0645(97)00096-9