Modeling variations of marine reservoir ages during the last 45 000 years
When dating marine samples with 14C, the reservoir-age effect is usually assumed to be constant, although atmospheric 14C production rate and ocean circulation changes cause temporal and spatial reservoir-age variations. These lead to dating errors, which can limit the interpretation of cause and ef...
Main Authors: | , , |
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Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Copernicus Publications
2008
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Subjects: | |
Online Access: | http://www.clim-past.net/4/125/2008/cp-4-125-2008.pdf https://doaj.org/article/cb520ed460a44e4fbccd98572ccde632 |
Summary: | When dating marine samples with 14C, the reservoir-age effect is usually assumed to be constant, although atmospheric 14C production rate and ocean circulation changes cause temporal and spatial reservoir-age variations. These lead to dating errors, which can limit the interpretation of cause and effect in paleoclimate data. We used a global ocean circulation model forced by transient atmospheric Δ14C variations to calculate reservoir ages for the last 45 000 years for a present day-like and a last glacial maximum-like ocean circulation. A ~30% reduced Atlantic meridonal overturning circulation leads to increased reservoir ages by up to ~500 years in high latitudes. Temporal variations are proportional to the absolute value of the reservoir age; regions with large reservoir age also show large variation. Temporal variations range between ~300 years in parts of the subtropics and ~1000 years in the Southern Ocean. For tropical regions, which are generally assumed to have nearly stable reservoir ages, the model suggests variations of several hundred years. |
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