A history of ENSO events since A.D. 1525: implications for future climate change
In: Climatic Change. Kluwer Academic: Dordrecht; Boston. ISSN 0165-0009; e-ISSN 1573-1480, more
|  |
| Authors | | Top |
- Gergis, J.L.
- Fowler, A.M.
|
|
|
| Abstract |
Reconstructions of past climate are important for providing a historical context for evaluating the nature of 20th century climate change. Here, a number of percentile-based palaeoclimate reconstructions were used to isolate signals of both phases of El NiA +/- o-Southern Oscillation (ENSO). A total of 92 (82) El NiA +/- o (La NiA +/- a) events were reconstructed since A.D. 1525. Significantly, we introduce the most comprehensive La NiA +/- a event record compiled to date. This annual record of ENSO events can now be used for independent verification of climate model simulations, reconstructions of ENSO indices and as a chronological control for archaeologists/social scientists interested in human responses to past climate events. Although extreme ENSO events are seen throughout the 478-year ENSO reconstruction, approximately 43% of extreme and 28% of all protracted ENSO events (i.e. both El NiA +/- o and La NiA +/- a phase) occur in the 20th century. The post-1940 period alone accounts for 30% of extreme ENSO years observed since A.D. 1525. These results suggest that ENSO may operate differently under natural (pre-industrial) and anthropogenic background states. As evidence of stresses on water supply, agriculture and natural ecosystems caused by climate change strengthens, studies into how ENSO will operate under global warming should be a global research priority. |
|
