Publication Date:
2019-08-08
Description:
We present a set of Porites coral oxygen isotope records from the tropical and subtropical
Western Indian Ocean covering the past 120–336 years. All records were
thoroughly validated for proxy response to regional climate factors and their relation
to large-scale climate modes. The records show markedly different imprints
of regional climate factors. At the same time, all coral records show clear teleconnections
between the Western Indian Ocean and the El Ni˜no–Southern Oscillation
(ENSO). The multi-proxy site analysis enables the detection of the covariance structure
between individual records and climate modes such as ENSO. This method
unravels shifts in ENSO teleconnectivity of the Western and Central Indian Ocean
on multi-decadal time-scales (after 1976). The Seychelles record shows a stationary
correlation with ENSO, Chagos corals show evidence for non-stationary δ18O/ENSO
relationships and the Southwestern Indian Ocean corals show a strong relationship
with ENSO when the forcing is strong (1880–1920, 1970 to present).
Our results indicate that the coral δ18O, in combination with other proxies, can
be used to monitor temporal and spatial variations in the sea-surface temperature
and the fresh water balance within the Indian Ocean on interannual to interdecadal
time-scales.
Type:
Article
,
PeerReviewed
Format:
text
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