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DiNezio PN, Tierney JE, Otto-Bliesner BL, Timmermann A, Bhattacharya T, Rosenbloom N, Brady E. Glacial changes in tropical climate amplified by the Indian Ocean. SCIENCE ADVANCES 2018; 4:eaat9658. [PMID: 30547084 PMCID: PMC6291310 DOI: 10.1126/sciadv.aat9658] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Accepted: 11/14/2018] [Indexed: 05/26/2023]
Abstract
The mechanisms driving glacial-interglacial changes in the climate of the Indo-Pacific warm pool are poorly understood. Here, we address this question by combining paleoclimate proxies with model simulations of the Last Glacial Maximum climate. We find evidence of two mechanisms explaining key patterns of ocean cooling and rainfall change interpreted from proxy data. Exposure of the Sahul shelf excites a positive ocean-atmosphere feedback involving a stronger surface temperature gradient along the equatorial Indian Ocean and a weaker Walker circulation-a response explaining the drier/wetter dipole across the basin. Northern Hemisphere cooling by ice sheet albedo drives a monsoonal retreat across Africa and the Arabian Peninsula-a response that triggers a weakening of the Indian monsoon via cooling of the Arabian Sea and associated reductions in moisture supply. These results demonstrate the importance of air-sea interactions in the Indian Ocean, amplifying externally forced climate changes over a large part of the tropics.
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Affiliation(s)
- Pedro N. DiNezio
- Institute for Geophysics, Jackson School of Geosciences, University of Texas at Austin, J.J. Pickle Research Campus, Building 196 10100 Burnet Road (R2200), Austin, TX 78758, USA
| | - Jessica E. Tierney
- Department of Geosciences, The University of Arizona, 1040 E 4th Street, Tucson, AZ 85721, USA
| | - Bette L. Otto-Bliesner
- National Center for Atmospheric Research, Climate and Global Dynamics Laboratory, 1850 Table Mesa Drive, Boulder, CO 80305, USA
| | - Axel Timmermann
- Center for Climate Physics, Institute for Basic Science, Busandaehak-ro 63beon-gil 2, Geumjeong-gu, Busan 46241, South Korea
- Pusan National University, Busandaehak-ro 63beon-gil 2, Geumjeong-gu, Busan 46241, South Korea
| | - Tripti Bhattacharya
- Department of Earth Science, Syracuse University, 204 Heroy Geology Laboratory, Syracuse, NY 13244-1070, USA
| | - Nan Rosenbloom
- National Center for Atmospheric Research, Climate and Global Dynamics Laboratory, 1850 Table Mesa Drive, Boulder, CO 80305, USA
| | - Esther Brady
- National Center for Atmospheric Research, Climate and Global Dynamics Laboratory, 1850 Table Mesa Drive, Boulder, CO 80305, USA
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Partin JW, Quinn TM, Shen CC, Okumura Y, Cardenas MB, Siringan FP, Banner JL, Lin K, Hu HM, Taylor FW. Gradual onset and recovery of the Younger Dryas abrupt climate event in the tropics. Nat Commun 2015; 6:8061. [PMID: 26329911 PMCID: PMC4569703 DOI: 10.1038/ncomms9061] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2014] [Accepted: 07/13/2015] [Indexed: 11/09/2022] Open
Abstract
Proxy records of temperature from the Atlantic clearly show that the Younger Dryas was an abrupt climate change event during the last deglaciation, but records of hydroclimate are underutilized in defining the event. Here we combine a new hydroclimate record from Palawan, Philippines, in the tropical Pacific, with previously published records to highlight a difference between hydroclimate and temperature responses to the Younger Dryas. Although the onset and termination are synchronous across the records, tropical hydroclimate changes are more gradual (>100 years) than the abrupt (10-100 years) temperature changes in the northern Atlantic Ocean. The abrupt recovery of Greenland temperatures likely reflects changes in regional sea ice extent. Proxy data and transient climate model simulations support the hypothesis that freshwater forced a reduction in the Atlantic meridional overturning circulation, thereby causing the Younger Dryas. However, changes in ocean overturning may not produce the same effects globally as in Greenland.
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Affiliation(s)
- J W Partin
- Institute for Geophysics, Jackson School of Geosciences, University of Texas at Austin, Austin, Texas 78758, USA
| | - T M Quinn
- Institute for Geophysics, Jackson School of Geosciences, University of Texas at Austin, Austin, Texas 78758, USA.,Department of Geological Sciences, Jackson School of Geosciences, University of Texas at Austin, Austin, Texas 78712, USA
| | - C-C Shen
- High-Precision Mass Spectrometry and Environment Change Laboratory (HISPEC), National Taiwan University, Taipei 10617, Taiwan, ROC
| | - Y Okumura
- Institute for Geophysics, Jackson School of Geosciences, University of Texas at Austin, Austin, Texas 78758, USA
| | - M B Cardenas
- Department of Geological Sciences, Jackson School of Geosciences, University of Texas at Austin, Austin, Texas 78712, USA
| | - F P Siringan
- Marine Science Institute, University of the Philippines-Diliman, Quezon City 1101, Philippines
| | - J L Banner
- Department of Geological Sciences, Jackson School of Geosciences, University of Texas at Austin, Austin, Texas 78712, USA
| | - K Lin
- High-Precision Mass Spectrometry and Environment Change Laboratory (HISPEC), National Taiwan University, Taipei 10617, Taiwan, ROC
| | - H-M Hu
- High-Precision Mass Spectrometry and Environment Change Laboratory (HISPEC), National Taiwan University, Taipei 10617, Taiwan, ROC
| | - F W Taylor
- Institute for Geophysics, Jackson School of Geosciences, University of Texas at Austin, Austin, Texas 78758, USA
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Hydroclimate of the western Indo-Pacific Warm Pool during the past 24,000 years. Proc Natl Acad Sci U S A 2014; 111:9402-6. [PMID: 24979768 DOI: 10.1073/pnas.1323585111] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The Indo-Pacific Warm Pool (IPWP) is a key site for the global hydrologic cycle, and modern observations indicate that both the Indian Ocean Zonal Mode (IOZM) and the El Niño Southern Oscillation exert strong influence on its regional hydrologic characteristics. Detailed insight into the natural range of IPWP dynamics and underlying climate mechanisms is, however, limited by the spatial and temporal coverage of climate data. In particular, long-term (multimillennial) precipitation patterns of the western IPWP, a key location for IOZM dynamics, are poorly understood. To help rectify this, we have reconstructed rainfall changes over Northwest Sumatra (western IPWP, Indian Ocean) throughout the past 24,000 y based on the stable hydrogen and carbon isotopic compositions (δD and δ(13)C, respectively) of terrestrial plant waxes. As a general feature of western IPWP hydrology, our data suggest similar rainfall amounts during the Last Glacial Maximum and the Holocene, contradicting previous claims that precipitation increased across the IPWP in response to deglacial changes in sea level and/or the position of the Intertropical Convergence Zone. We attribute this discrepancy to regional differences in topography and different responses to glacioeustatically forced changes in coastline position within the continental IPWP. During the Holocene, our data indicate considerable variations in rainfall amount. Comparison of our isotope time series to paleoclimate records from the Indian Ocean realm reveals previously unrecognized fluctuations of the Indian Ocean precipitation dipole during the Holocene, indicating that oscillations of the IOZM mean state have been a constituent of western IPWP rainfall over the past ten thousand years.
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Carolin SA, Cobb KM, Adkins JF, Clark B, Conroy JL, Lejau S, Malang J, Tuen AA. Varied response of western Pacific hydrology to climate forcings over the last glacial period. Science 2013; 340:1564-6. [PMID: 23744779 DOI: 10.1126/science.1233797] [Citation(s) in RCA: 114] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Atmospheric deep convection in the west Pacific plays a key role in the global heat and moisture budgets, yet its response to orbital and abrupt climate change events is poorly resolved. Here, we present four absolutely dated, overlapping stalagmite oxygen isotopic records from northern Borneo that span most of the last glacial cycle. The records suggest that northern Borneo's hydroclimate shifted in phase with precessional forcing but was only weakly affected by glacial-interglacial changes in global climate boundary conditions. Regional convection likely decreased during Heinrich events, but other Northern Hemisphere abrupt climate change events are notably absent. The new records suggest that the deep tropical Pacific hydroclimate variability may have played an important role in shaping the global response to the largest abrupt climate change events.
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Affiliation(s)
- Stacy A Carolin
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA 30332, USA.
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