title: Coralline algal barium as indicator for 20th century northwestern North Atlantic surface ocean freshwater variability.
abstract: During the past decades climate and freshwater dynamics in the northwestern North Atlantic have undergone major changes. Large-scale freshening episodes, related to polar freshwater pulses, have had a strong influence on ocean variability in this climatically important region. However, little is known about variability before 1950, mainly due to the lack of long-term high-resolution marine proxy archives. Here we present the first multidecadal-length records of annually resolved Ba/Ca variations from Northwest Atlantic coralline algae. We observe positive relationships between algal Ba/Ca ratios from two Newfoundland sites and salinity observations back to 1950. Both records capture episodical multi-year freshening events during the 20th century. Variability in algal Ba/Ca is sensitive to freshwater-induced changes in upper ocean stratification, which affect the transport of cold, Ba-enriched deep waters onto the shelf (highly stratified equals less Ba/Ca). Algal Ba/Ca ratios therefore may serve as a new resource for reconstructing past surface ocean freshwater changes.
authors: CPS-Department, University of Toronto Mississauga, 3359 Mississauga Rd. N, Mississauga, ON, L5L 1C6, Canada. shetzinger@geomar.de
authors: S
authors: S
authors: Hetzinger
authors: J
authors: J
authors: Halfar
authors: T
authors: T
authors: Zack
authors: J V
authors: JV
authors: Mecking
authors: B E
authors: BE
authors: Kunz
authors: D E
authors: DE
authors: Jacob
authors: W H
authors: WH
authors: Adey
mesh_terms: D001464:Barium / Q000737:chemistry*; D002118:Calcium / Q000032:analysis / Q000737:chemistry; D000460:Chlorophyta / Q000378:metabolism; D002980:Climate; D005618:Fresh Water / Q000032:analysis* / Q000737:chemistry* / Q000382:microbiology; D009792:Oceans and Seas; D054712:Salinity; D012623:Seawater / Q000032:analysis* / Q000737:chemistry* / Q000382:microbiology; D013696:Temperature
chemical_list: D001464:Barium; D002118:Calcium
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