01-05 December 2025
INCOIS, Hyderabad, India.
| Abstract Submission No. | ABS-04-0111 |
| Title of Abstract | Decadal variability of Sea Surface Temperatures in the Western Indian Ocean over the Common Era |
| Authors | SICRE, M.-A.*, Jouet G., Caley T., Klein V., Azuara J. |
| Organisation | LOCEAN, CNRS, Sorbonne Université, 4 place Jussieu, Paris |
| Address | 3 Rue Michel-ange Paris, Paris, France Pincode: 75016 E-mail: marie-alexandrine.sicre@locean.ipsl.fr |
| Country | France |
| Presentation | Oral |
| Abstract | Long-term Sea Surface Temperature (SST) records in the Indian Ocean are very few hindering our understanding of decadal to multi-decadal climate variability in the region. Here, we present the first SST reconstruction obtained in the western Indian Ocean, resolving decadal variability over the last 2000 years (Common Era). Our data show strong multi-decadal oscillations between 27.2 and 28.2°C and a 1°C warming since 1800 AD. Several cold periods are identified after the major volcanic eruptions of the last millennium, e.g. the Samalas, Kuwae, and Tambora. The more pronounced and persistent coldness associated with the Kuwae and Tambora eruptions likely reflects an amplification effect due to their concomitance with solar minima. Comparison with the extratropical temperature reconstruction of Moberg et al. (2005) reveals a delayed return to pre-eruption temperatures in the extratropics as compared to the tropics that is imputable to feedbacks mechanisms due to sea ice. Our results also evidence a two-phase Medieval Climate Anomaly (MCA) with a first colder interval (900-1050 AD) followed by a rapid transition into a second warmer interval (1050-1250 AD) each reflecting different ENSO phases. Wavelet analysis of the 2000-year SST signal demonstrates a strong remote influence of ENSO and coherency with the Laguna Pallcacocha ENSO record, Ecuador. Cold surface time spans of the last millennium, e.g. the Early MCA and those triggered by volcanic forcing, were associated with prolonged La Niña-like conditions in the Eastern Equatorial Pacific. |
| Are you part of IIOE-2 endorsed project | yes |
| Endorsed Project Number | IIOE2-EP55 |
| Keywords | SST, proxy reconstruction, Common Era, ENSO |
| For Awards | no |