Publication Date:
2018-03-12
Description:
El Nino events are characterized by anomalously warm tropical Pacific surface waters and concurrent ocean heat discharge, a precursor of subsequent cold La Nina conditions. Here we show that El Nino 2015/16 departed from this norm: despite extreme peak surface temperatures, Tropical Pacific (30N-30S) upper ocean heat content (OHC) increased by 9.6±1.7 ZJ (1ZJ=10 21 J), in stark contrast to the previous strong El Nino in 1997/98 (-11.5±2.9 ZJ). Unprecedented reduction of Indonesian Throughflow volume and heat transport played a key role in the anomalous 2015/16 event. We argue that this anomaly is linked with the previously documented intensified warming and associated rising sea levels in the Indian Ocean during the last decade. Additionally, increased absorption of solar radiation acted to dampen Pacific OHC discharge. These results explain the weak and short-lived La Nina conditions in 2016/17 and indicate the need for realistic representation of Indo-Pacific energy transfers for skilful seasonal-to-decadal predictions.
Print ISSN:
0094-8276
Electronic ISSN:
1944-8007
Topics:
Geosciences
,
Physics
