DOI: 10.1016/j.palaeo.2016.02.001
论文题名: Coral δ18O evidence for Pacific Ocean mediated decadal variability in Panamanian ITCZ rainfall back to the early 1700s
作者: Brenner L.D. ; Linsley B.K. ; Dunbar R.B. ; Wellington G.
刊名: Palaeogeography, Palaeoclimatology, Palaeoecology
ISSN: 0031-0182
出版年: 2016
卷: 449 起始页码: 385
结束页码: 396
语种: 英语
英文关键词: Coral
; Intertropical convergence zone
; Pacific decadal oscillation
; Panama
; Porites
英文摘要: In Central America, seasonal and interannual shifts in the position of the Intertropical Convergence Zone (ITCZ) control the hydrologic budget. To better understand long-term changes in regional ITCZ-driven precipitation we re-examined a coral δ18O record from a Porites lobata coral head near Secas Island (Core ID: S1) (7°59' N, 82°3' W) in the Gulf of Chiriquí on the Pacific side of Panamá. Linsley et al., (1994) originally published the 277-year time series and first described the presence of a narrow-band decadal cycle (period near 9-12 years) in δ18O. The original study did not present potential drivers for the decadal cycle, although they ruled out the influence of the sun spot cycle. Our re-analysis of this record supports the original interpretation that coral δ18O is largely responding to variations in precipitation and associated river discharge, but with a new proposed mechanism to explain the decadal mode. There is no similar decadal cycle in gridded instrumental sea surface temperature from the area, suggesting that the decadal coral δ18O signal results from hydrologic changes that influence coastal δ18Oseawater. The decadal component in S1 δ18O is also coherent with a decadal mode embedded in the Pacific Decadal Oscillation (PDO) Index that we suggest has tropical origins. We speculate that the coral's temporary δ18O deviation (1900-1930) in the decadal mode from the corresponding bands in rainfall and the PDO can be ascribed to a weak PDO in addition to local Panama gap wind variability and its effect on moisture transport from the Atlantic to the Pacific. Ultimately, the Secas Island coral δ18O series records ITCZ-driven precipitation dictated by both the Atlantic and Pacific basins. © 2016 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/68498
Appears in Collections: 过去全球变化的重建
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作者单位: Lamont-Doherty Earth Observatory, Geoscience 104, 61 Route 9W, Palisades, NY, United States; Department of Earth and Environmental Science, Columbia University, New York, NY, United States; Department of Environmental Earth Systems Science, Stanford University, Stanford, CA, United States; Department of Biology, University of Houston, Houston, TX, United States
Recommended Citation:
Brenner L.D.,Linsley B.K.,Dunbar R.B.,et al. Coral δ18O evidence for Pacific Ocean mediated decadal variability in Panamanian ITCZ rainfall back to the early 1700s[J]. Palaeogeography, Palaeoclimatology, Palaeoecology,2016-01-01,449