Extended Data Table 1 Simulated ENSO dominant periods in the RO

From: Increased frequency of multi-year El Niño–Southern Oscillation events across the Holocene

r=0.25, α=0.125, b=2.22, b_0=2.5, R=0.667, γ=0.75, μ=8/9, and e_n=3

λ

Period (years)

λ *(1+sin(2πt/T))

Period (years)

 

0

3.82

0

3.82

 

0.1

3.93

0.1

4.01

 

0.2

4.08

0.2

4.01

 

0.3

4.29

0.3

4.21

 

0.4

4.63

0.4

4.48

 

  1. The simulated ENSO dominant periods in the RO with variable thermocline depth (modulated by λ). A larger λ means a shallower thermocline depth. The seasonally-varying λ can approximate deeper thermocline particularly during the first half of year in the early/mid Holocene due to orbital forcing (Extended Data Fig. 5). The results show that the deeper thermocline-longer ENSO period relationship generally exists irrespective of whether λ has a seasonal cycle or not.