Due Diligence - ONE

Updated: 02/12/2018

A comparison between the two 31-year Full Moon Epochs:

Epoch 2 - 15th April 1870 to 18th April 1901
Epoch 6 - 25th April 1994 to 27th April 2025

Moderate-to-strong El Niño events in the Full Moon epochs preferentially occur near times when the lunar line-of-apse aligns with the Sun at the times of the Equinoxes. Note that this is equivalent to saying that moderate to strong El Niño in Full Moon Epochs preferentially occur near times the strongest Perigean New/Full moons are crossing the Earth's equator.

A comparison between the two 31-year New Moon Epochs:

Epoch 3 - 8th April 1901 to 20th April 1932

Epoch 5 - 23rd April 1963 to 25th April 1994

Moderate-to-strong El Niño events in the New Moon epochs preferentially occur near times when the lunar line-of-apse aligns with the Sun at the times of the Solstices. Note that this is equivalent to saying that moderate to strong El Niño in New Moon Epochs preferentially occur near times the strongest Perigean New/Full moons are near lunar standstill.

Note: The El Nino events in Epoch 5 (shown above) that obey the general rule are arbitrarily flipped up and down to highlight the synchronicity with the Perigean lunar cycle (i.e. blue curve).

N.B. Looking at the starting months of the El Nino events during epoch 2, 3, 5, and 6:

1. There are 29 El Nino events in total

2. Six of these events only last for 3 months or less and so do not meet the adopted threshold of being moderate to strong El Nino events:

1915 (3 months)

1923 (2 months)

1931 (1 month)

1969 (3 months)

2004 (3 months)

2006 (2 months)

of these 1915, 1969, and 2006 obey the general rules, while 1923 and 2004 do not obey the general rules. The 1931 event is a transitional event.

3. There are four threshold events that are exceptions that occur during the transition periods between New and Full Moon Epochs:

Epoch 3 -- 1905

Epoch 5 -- 1963 & 1993

Epoch 6 -- 1994/95

3. If you exclude the six sub-threshold events and the four transition events, this leaves 19 El Nino events.

4. Of these, there are two El Nino events that are significant exceptions to the general rules:

1918/19

2009/10

Conclusion: 89 % of the El Nino events (i.e. 17/19) obey the general rule.