Abstract
We have generated a high‐resolution coral Δ14C record from the leeward side of the Big Island of Hawai’i in the subtropical North Pacific. The record spans 1947‐1992, when the coral was collected, and includes a brief prebomb interval as well as the post‐bomb era. Mean prebomb (1947‐1954) values average ‐55‰ (±1, SE of the mean) with a clear seasonal cycle. Values are less positive during winter when vertical exchange mixes surface and lower‐14C subsurface waters. The post‐bomb annual maximum occurs in 1971 (+160‰) and decreases in a series of shifts to +105‰ in 1991, the end of our coral‐based reconstruction. The decrease is not monotonic and has inflection points during the La Niña years of 1973, 1977, and 1984. Imbedded in the Δ14C record is interannual variability in the El Nino‐Southern Oscillation band which is interpreted to reflect the lateral advection of low latitude surface waters as part of the oceanic Hadley Cell driven by Sverdrup dynamics.
Original language | English |
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Article number | e2020JC016881 |
Journal | Journal of Geophysical Research Oceans |
Volume | 126 |
Issue number | 2 |
Early online date | 17 Jan 2021 |
DOIs | |
Publication status | Published - Feb 2021 |
Bibliographical note
Funding Information:Coral cores were collected and supplied by Eric Cathcart, Sarah Gray, Gordon Tribble, and Sheila Griffin. Ethan Goddard supervised milling and all stable isotope and ICP‐OES analyses. We thank Brian Frantz, Jessica Westbrook, and Paula Zermeño for pressing targets made by TG. The "Arand" spectral package was maintained and distributed by Phil Howell, Brown University. We are particularly grateful to Keith Rodgers who provided comments, criticisms, and stimulated additional thinking on an early version of this manuscript. The analytical work was supported by grants to T. Guilderson and M. Kashgarian (98ERI002), to D. Schrag from NSF's program in Physical Oceanography (OCE‐9796253) and to E. Druffel from NSF's program in Chemical Oceanography (OCE‐8915919 and OCE‐9314691). Portions of this work were performed under the auspices of the U.S. Department of Energy by the Lawrence Livermore National Laboratory under contracts W‐7405‐Eng‐48 and DE‐AC52‐07NA27344.
Funding Information:
Coral cores were collected and supplied by Eric Cathcart, Sarah Gray, Gordon Tribble, and Sheila Griffin. Ethan Goddard supervised milling and all stable isotope and ICP-OES analyses. We thank Brian Frantz, Jessica Westbrook, and Paula Zerme?o for pressing targets made by TG. The "Arand" spectral package was maintained and distributed by Phil Howell, Brown University. We are particularly grateful to Keith Rodgers who provided comments, criticisms, and stimulated additional thinking on an early version of this manuscript. The analytical work was supported by grants to T. Guilderson and M. Kashgarian (98ERI002), to D. Schrag from NSF's program in Physical Oceanography (OCE-9796253) and to E. Druffel from NSF's program in Chemical Oceanography (OCE-8915919 and OCE-9314691). Portions of this work were performed under the auspices of the U.S. Department of Energy by the Lawrence Livermore National Laboratory under contracts W-7405-Eng-48 and DE-AC52-07NA27344.
Publisher Copyright:
© 2021. American Geophysical Union. All Rights Reserved.
Copyright:
Copyright 2021 Elsevier B.V., All rights reserved.
Keywords
- air-sea CO2 exchange
- North Pacific Gyre
- radiocarbon
- surface water exchange
ASJC Scopus subject areas
- Geochemistry and Petrology
- Geophysics
- Earth and Planetary Sciences (miscellaneous)
- Space and Planetary Science
- Oceanography