El Niño–Southern Oscillation and internal sea surface temperature variability in the tropical Indian Ocean since 1675
<p>The dominant modes of climate variability on interannual timescales in the tropical Indian Ocean are the El Niño–Southern Oscillation (ENSO) and the Indian Ocean Dipole. El Niño events have occurred more frequently during recent decades, and it has been suggested that an asymmetric ENSO tel...
| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2021-01-01
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| Series: | Climate of the Past |
| Online Access: | https://cp.copernicus.org/articles/17/151/2021/cp-17-151-2021.pdf |
| _version_ | 1819051040568246272 |
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| author | M. Leupold M. Pfeiffer T. K. Watanabe L. Reuning D. Garbe-Schönberg C.-C. Shen C.-C. Shen C.-C. Shen G.-J. A. Brummer |
| author_facet | M. Leupold M. Pfeiffer T. K. Watanabe L. Reuning D. Garbe-Schönberg C.-C. Shen C.-C. Shen C.-C. Shen G.-J. A. Brummer |
| author_sort | M. Leupold |
| collection | DOAJ |
| description | <p>The dominant modes of climate variability on interannual
timescales in the tropical Indian Ocean are the El Niño–Southern
Oscillation (ENSO) and the Indian Ocean Dipole. El Niño events have
occurred more frequently during recent decades, and it has been suggested
that an asymmetric ENSO teleconnection (warming during El Niño events is
stronger than cooling during La Niña events) caused the pronounced
warming of the western Indian Ocean. In this study, we test this hypothesis
using coral <span class="inline-formula">Sr∕Ca</span> records from the central Indian Ocean (Chagos Archipelago)
to reconstruct past sea surface temperatures (SSTs) in time windows from the
mid-Little Ice Age (1675–1716) to the present. Three sub-fossil massive
<i>Porites</i> corals were dated to the 17–18th century (one coral) and the 19–20th
century (two corals). Their records were compared with a published modern
coral <span class="inline-formula">Sr∕Ca</span> record from the same site. All corals were subsampled at a
monthly resolution for <span class="inline-formula">Sr∕Ca</span> measurements, which were measured using a
simultaneous inductively coupled plasma optical emission spectrometer (ICP-OES). Wavelet coherence analysis shows that interannual
variability in the four coral records is driven by ENSO, suggesting that the
ENSO–SST teleconnection in the central Indian Ocean has been stationary since the
17th century. To determine the symmetry of El Niño and La Niña
events, we compiled composite records of positive and negative ENSO-driven
SST anomaly events. We find similar magnitudes of warm and cold anomalies,
indicating a symmetric ENSO response in the tropical Indian Ocean. This
suggests that ENSO is not the main driver of central Indian Ocean warming.</p> |
| first_indexed | 2024-12-21T11:57:37Z |
| format | Article |
| id | doaj.art-a002a5fe301a47d6bfe3a9ac84ede18d |
| institution | Directory Open Access Journal |
| issn | 1814-9324 1814-9332 |
| language | English |
| last_indexed | 2024-12-21T11:57:37Z |
| publishDate | 2021-01-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Climate of the Past |
| spelling | doaj.art-a002a5fe301a47d6bfe3a9ac84ede18d2022-12-21T19:04:54ZengCopernicus PublicationsClimate of the Past1814-93241814-93322021-01-011715117010.5194/cp-17-151-2021El Niño–Southern Oscillation and internal sea surface temperature variability in the tropical Indian Ocean since 1675M. Leupold0M. Pfeiffer1T. K. Watanabe2L. Reuning3D. Garbe-Schönberg4C.-C. Shen5C.-C. Shen6C.-C. Shen7G.-J. A. Brummer8Energy and Mineral Resources Group (EMR), Geological Institute, RWTH Aachen University, 52062 Aachen, GermanyInstitute of Geosciences, Kiel University, 24118 Kiel, GermanyDepartment of Natural History Sciences, Faculty of Science, Hokkaido University, Sapporo 060-0810, JapanInstitute of Geosciences, Kiel University, 24118 Kiel, GermanyInstitute of Geosciences, Kiel University, 24118 Kiel, GermanyHigh-Precision Mass Spectrometry and Environment Change Laboratory (HISPEC), Department of Geosciences, National Taiwan University, Taipei 10617, TaiwanResearch Center for Future Earth, National Taiwan University, Taipei LC6L73, TaiwanGlobal Change Research Center, National Taiwan University, Taipei 10617, TaiwanDepartment of Ocean Systems, Royal Netherlands Institute for Sea Research (NIOZ), and Utrecht University, 1790 Den Burg, The Netherlands<p>The dominant modes of climate variability on interannual timescales in the tropical Indian Ocean are the El Niño–Southern Oscillation (ENSO) and the Indian Ocean Dipole. El Niño events have occurred more frequently during recent decades, and it has been suggested that an asymmetric ENSO teleconnection (warming during El Niño events is stronger than cooling during La Niña events) caused the pronounced warming of the western Indian Ocean. In this study, we test this hypothesis using coral <span class="inline-formula">Sr∕Ca</span> records from the central Indian Ocean (Chagos Archipelago) to reconstruct past sea surface temperatures (SSTs) in time windows from the mid-Little Ice Age (1675–1716) to the present. Three sub-fossil massive <i>Porites</i> corals were dated to the 17–18th century (one coral) and the 19–20th century (two corals). Their records were compared with a published modern coral <span class="inline-formula">Sr∕Ca</span> record from the same site. All corals were subsampled at a monthly resolution for <span class="inline-formula">Sr∕Ca</span> measurements, which were measured using a simultaneous inductively coupled plasma optical emission spectrometer (ICP-OES). Wavelet coherence analysis shows that interannual variability in the four coral records is driven by ENSO, suggesting that the ENSO–SST teleconnection in the central Indian Ocean has been stationary since the 17th century. To determine the symmetry of El Niño and La Niña events, we compiled composite records of positive and negative ENSO-driven SST anomaly events. We find similar magnitudes of warm and cold anomalies, indicating a symmetric ENSO response in the tropical Indian Ocean. This suggests that ENSO is not the main driver of central Indian Ocean warming.</p>https://cp.copernicus.org/articles/17/151/2021/cp-17-151-2021.pdf |
| spellingShingle | M. Leupold M. Pfeiffer T. K. Watanabe L. Reuning D. Garbe-Schönberg C.-C. Shen C.-C. Shen C.-C. Shen G.-J. A. Brummer El Niño–Southern Oscillation and internal sea surface temperature variability in the tropical Indian Ocean since 1675 Climate of the Past |
| title | El Niño–Southern Oscillation and internal sea surface temperature variability in the tropical Indian Ocean since 1675 |
| title_full | El Niño–Southern Oscillation and internal sea surface temperature variability in the tropical Indian Ocean since 1675 |
| title_fullStr | El Niño–Southern Oscillation and internal sea surface temperature variability in the tropical Indian Ocean since 1675 |
| title_full_unstemmed | El Niño–Southern Oscillation and internal sea surface temperature variability in the tropical Indian Ocean since 1675 |
| title_short | El Niño–Southern Oscillation and internal sea surface temperature variability in the tropical Indian Ocean since 1675 |
| title_sort | el nino southern oscillation and internal sea surface temperature variability in the tropical indian ocean since 1675 |
| url | https://cp.copernicus.org/articles/17/151/2021/cp-17-151-2021.pdf |
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