Atmospheric and oceanic evidences of El Niño-Southern Oscillation events in the south central Pacific Ocean from coral stable isotopic records over the last 137 years

Muriel Boiseau (1) , Anne Juillet-Leclerc (1, 2) , Pascal Yiou (1, 3) , Bernard Salvat (4) , Peter Isdale (5) , Mireille Guillaume (6)

1 LSCE - Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette]
2 PALEOCEAN - Paléocéanographie
3 ESTIMR - Extrèmes : Statistiques, Impacts et Régionalisation
4 ENTROPIE [Perpignan] - Ecologie marine tropicale des océans Pacifique et Indien
5 AIMS - Australian Institute of Marine Science
6 BIMM - Laboratoire de biologie des invertébrés marins et malacologie

We measured fi'•O and fi'3C in Porites lutea collected in the Moorea lagoon where the instrumental records show that an E1 Nifio-Southern Oscillation (ENSO) event implies both a cloud cover decrease and a weak sea surface temperature (SST) increase. Two proxies allow an ENSO record to be reconstructed at Moorea: the annual fi'3C anomaly, associated with the South Pacific Convergence Zone motion, and an annual fi'•O anomaly showing increased SST. The frequency bands exhibited by the singular spectral analysis (SSA) and the multitaper method of the annual •5•O and •5' 3C records are centered on 2.5 and 5.2 years and 2.4 and 3.2 years, respectively, which are the main ENSO modes. We used SSA to reconstruct ENSO events at Moorea over the past 137 years. Results indicate that climate variability at this site is strongly affectedby ENSO events.

Domaines: Océan, Atmosphère; Interfaces continentales, environnement

Muriel Boiseau, Anne Juillet-Leclerc, Pascal Yiou, Bernard Salvat, Peter Isdale, et al.. Atmospheric and oceanic evidences of El Niño-Southern Oscillation events in the south central Pacific Ocean from coral stable isotopic records over the last 137 years. Paleoceanography, 1998, 13 (6), pp.671-685. ⟨10.1029/98PA02502⟩. ⟨hal-02955571⟩