Spatial and temporal variability of surface water in the Kuroshio source region, Pacific Ocean, over the past 21,000 years: evidence from planktonic foraminifera

ABSTRACTWe report marine dissolved organic carbon (DOC) ∆14C from seawater collected from the North central Pacific Ocean (NCP) in 2015. These measurements show DOC ∆14C values averaged –235±5‰ (n=3) in the mixed layer (24–81 m) and –544±5‰ (n=5) in the deep water (1500–5139 m). A comparison of these data with two previously published DOC ∆14C profiles from the NCP in 1985 and 1987 reveals that deep DOC ∆14C values have decreased. We discuss several possible mechanisms that could cause such a shift in DOC ∆14C values, including spatial inhomogeneity and temporal variability due to changes in the dissolution and ∆14C value of surface derived particles in the deep sea. We find that forthcoming profiles of DOC ∆14C results from the NCP will determine the primary mechanisms controlling deep DOC ∆14C distributions, and changes over the past three decades.

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Spatial and temporal variability of the surface water pCO2and air-sea CO2flux in the equatorial Pacific during 1980–2003: A basin-scale carbon cycle model

Journal of Geophysical Research Atmospheres ◽

10.1029/2005jc002972 ◽

2006 ◽

Vol 111 (C7) ◽

Cited By ~ 31

Author(s):

Xiujun Wang ◽

James R. Christian ◽

Ragu Murtugudde ◽

Antonio J. Busalacchi

Keyword(s):

Surface Water ◽

Carbon Cycle ◽

Temporal Variability ◽

Equatorial Pacific ◽

Spatial And Temporal Variability ◽

Cycle Model ◽

Carbon Cycle Model ◽

Basin Scale

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Spatio-temporal variability in volcanic sulphate deposition over the past 2 kyr in snow pits and firn cores from Amundsenisen, Antarctica

Journal of Glaciology ◽

10.3189/172756504781830222 ◽

2004 ◽

Vol 50 (168) ◽

pp. 137-146 ◽

Cited By ~ 75

Author(s):

Fidan Traufetter ◽

Hans Oerter ◽

Hubertus Fischer ◽

Rolf Weller ◽

Heinz Miller

Keyword(s):

Temporal Variability ◽

Ionic Composition ◽

Ice Cores ◽

Volcanic Eruptions ◽

Detection Algorithm ◽

Snow Accumulation ◽

Spatial And Temporal Variability ◽

The Past ◽

Annual Layer ◽

Sulphate Deposition

AbstractIn the framework of the European Project for Ice Coring in Antarctica (EPICA), a comprehensive glaciological pre-site survey has been carried out on Amundsenisen, Dronning Maud Land, East Antarctica, in the past decade. Within this survey, four intermediate-depth ice cores and 13 snow pits were analyzed for their ionic composition and interpreted with respect to the spatial and temporal variability of volcanic sulphate deposition. The comparison of the non-sea-salt (nss)-sulphate peaks that are related to the well-known eruptions of Pinatubo and Cerro Hudson in AD 1991 revealed sulphate depositions of comparable size (15.8±3.4 kg km–2) in 11 snow pits. There is a tendency to higher annual concentrations for smaller snow-accumulation rates. The combination of seasonal sodium and annually resolved nss-sulphate records allowed the establishment of a time-scale derived by annual-layer counting over the last 2000 years and thus a detailed chronology of annual volcanic sulphate deposition. Using a robust outlier detection algorithm, 49 volcanic eruptions were identified between AD 165 and 1997. The dating uncertainty is ±3 years between AD 1997 and 1601, around ±5 years between AD 1601 and 1257, and increasing to ±24 years at AD 165, improving the accuracy of the volcanic chronology during the penultimate millennium considerably.

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