The information on this WWW page is taken from Quinn, W. H., V. T. Neal, and S. E. Antunez de Mayolo, 1987: El Niño occurrences over the past four and a half centuries. J. Geophys. Res., 92, 14449-14461. The authors based their El Niño identification on a broad range of subjective and objective measures, which are described below.
Quinn et al. employed the following six categories. Note that they only began identifying moderate El Niños (categories 1-3) in 1806.
0 neutral or cold
1 weak moderate
2 moderate
3 "moderate +"
4 strong
5 "strong +"
6 very strong
The first data value is for 1525 and it is "strong." Quinn et al. only began identifying weak-moderate, moderate and "moderate +" El Niños in 1806.
+0 1 2 3 4 5 6 7 8 9
1520 4 4 0 0 0
1530 0 4 4 0 0 0 0 0 0 4
1540 4 4 0 0 0 0 0 0 0 0
1550 0 0 4 0 0 0 0 0 0 0
1560 0 0 0 0 0 0 0 5 5 0
1570 0 0 0 0 4 0 0 0 6 0
1580 0 0 0 0 0 0 0 0 0 0
1590 0 4 4 0 0 0 0 0 0 0
1600 0 0 0 0 0 0 0 4 0 0
1610 0 0 0 0 4 0 0 0 4 4
1620 0 0 0 0 5 0 0 0 0 0
1630 0 0 0 0 4 0 0 0 0 0
1640 0 0 0 0 0 0 0 0 0 0
1650 0 0 5 0 0 0 0 0 0 0
1660 4 0 0 0 0 0 0 0 0 0
1670 0 4 0 0 0 0 0 0 0 0
1680 0 4 0 0 0 0 0 5 5 0
1690 0 0 0 0 0 0 4 0 0 0
1700 0 5 0 0 0 0 0 4 4 0
1710 0 0 0 0 4 4 0 0 0 0
1720 5 0 0 0 0 0 0 0 6 0
1730 0 0 0 0 0 0 0 0 0 0
1740 0 0 0 0 0 0 0 4 0 0
1750 0 0 0 0 0 0 0 0 0 0
1760 0 4 0 0 0 0 0 0 0 0
1770 0 0 0 0 0 4 0 0 0 0
1780 0 0 0 0 0 4 4 0 0 0
1790 0 6 0 0 0 0 0 0 0 0
1800 0 0 0 5 0 0 2 2 0 0
1810 0 0 2 0 4 0 0 3 0 3
1820 0 2 0 0 2 0 0 0 6 0
1830 0 0 2 0 0 0 0 2 0 0
1840 0 0 0 0 5 5 0 0 0 0
1850 2 0 0 0 1 0 0 3 3 0
1860 2 0 0 0 4 0 2 2 2 0
1870 0 5 0 0 2 0 0 6 6 0
1880 2 0 0 0 5 0 0 1 1 1
1890 0 6 0 0 0 0 3 3 0 4
1900 4 0 3 0 0 1 0 2 0 0
1910 0 4 4 0 3 0 0 4 1 1
1920 0 0 0 2 0 6 6 0 0 0
1930 1 1 4 0 0 0 0 0 0 3
1940 4 4 0 3 0 0 0 0 0 0
1950 0 1 0 3 0 0 0 4 4 0
1960 0 0 0 0 0 3 0 0 0 0
1970 0 0 4 4 0 0 2 0 0 0
1980 0 0 6 6 0 0 0 2
Confidence index: minimum 2 to maximum of 5.
+0 1 2 3 4 5 6 7 8 9
1520 3 3 0 0 0
1530 0 4 4 0 0 0 0 0 0 3
1540 3 3 0 0 0 0 0 0 0 0
1550 0 0 4 0 0 0 0 0 0 0
1560 0 0 0 0 0 0 0 5 5 0
1570 0 0 0 0 4 0 0 0 5 0
1580 0 0 0 0 0 0 0 0 0 0
1590 0 2 2 0 0 0 0 0 0 0
1600 0 0 0 0 0 0 0 5 0 0
1610 0 0 0 0 5 0 0 0 4 4
1620 0 0 0 0 4 0 0 0 0 0
1630 0 0 0 0 4 0 0 0 0 0
1640 0 0 0 0 0 0 0 0 0 0
1650 0 0 4 0 0 0 0 0 0 0
1660 3 0 0 0 0 0 0 0 0 0
1670 0 3 0 0 0 0 0 0 0 0
1680 0 3 0 0 0 0 0 4 4 0
1690 0 0 0 0 0 0 3 0 0 0
1700 0 4 0 0 0 0 0 3 3 0
1710 0 0 0 0 4 4 0 0 0 0
1720 4 0 0 0 0 0 0 0 5 0
1730 0 0 0 0 0 0 0 0 0 0
1740 0 0 0 0 0 0 0 5 0 0
1750 0 0 0 0 0 0 0 0 0 0
1760 0 5 0 0 0 0 0 0 0 0
1770 0 0 0 0 0 4 0 0 0 0
1780 0 0 0 0 0 4 4 0 0 0
1790 0 5 0 0 0 0 0 0 0 0
1800 0 0 0 5 0 0 3 3 0 0
1810 0 0 4 0 4 0 0 5 0 4
1820 0 5 0 0 5 0 0 0 5 0
1830 0 0 5 0 0 0 0 5 0 0
1840 0 0 0 0 5 5 0 0 0 0
1850 5 0 0 0 4 0 0 5 5 0
1860 4 0 0 0 5 0 4 4 4 0
1870 0 5 0 0 4 0 0 5 5 0
1880 4 0 0 0 5 0 0 5 5 5
1890 0 5 0 0 0 0 4 4 0 5
1900 5 0 4 0 0 4 0 3 0 0
1910 0 4 4 0 5 0 0 5 5 5
1920 0 0 0 5 0 5 5 0 0 0
1930 5 5 5 0 0 0 0 0 0 5
1940 5 5 0 5 0 0 0 0 0 0
1950 0 5 0 5 0 0 0 5 5 0
1960 0 0 0 0 0 5 0 0 0 0
1970 0 0 5 5 0 0 5 0 0 0
1980 0 0 5 5 0 0 0 4
Quinn and collaborators based their identification upon a literature search and, for the modern record, sea surface temperature observations at stations along the Peru coast.
"In our search of the literature we looked for occurrences of the
following nature over the north Peruvian coastal region and its
adjacent waters:
1) significant variations on travel times between ports along the
coast of Peru (e.g., large increases in northward travel time and
decreases in southward travel time because of southward coastal
currents and / or winds),
2) data from ship logs (pirates, privateers, explorers, etc.) noting
unusual sea and weather conditions, sensing unusual sea and air
temperatures, sighting displaced continental vegetation, noting
displaced marine fauna, etc.,
3) presence of aguaje (red tide),
4) penetration of abnormally warm waters farther south than usual
along the coast of Peru during southern hemisphere summer and/or fall,
5) abnormally high air temperatures in the coastal cities of northern
Peru,
6) thunderstorms, heavy rainfall, and /or flood conditions,
7) destruction of buildings, houses, and sometimes whole cities in the
coastal zone by river inundations and flood waters,
8) obstructions to travel as the result of destruction of bridges,
roadways, and/or railroad facilities by hydrological forces,
9) destruction of agricultural crops,
10) significant rises in sea temperatures and sea levels,
11) southward invasions of tropical nekton,
12) mass mortality of endemic marine sea life,
13) death and/or departure of guano birds, and
14) reduction in coastal fishery and fish meal production."
The definition of El Niño posited by the Scientific Committee on Oceanic Research (1983) was employed: "El Niño is the appearance of anomalously warm water along the coast of Ecuador and Peru as far south as Lima (12 °S), during which a normalized sea surface temperature (SST) anomaly exceeding one standard deviation occurs for at least four consecutive months at three or more of five coastal stations (Talara, Puerto Chicama, Chimbote, Isla Don Martin, and Callao)." The SCOR definition employed 1956-81 for the climatology.
El Niño's with confidence ratings of 1 are not listed in the table "since they were merely listed by an author, without any source reference or informational basis,and one of our goals was to elimainate unsubstantated events. The other ratings are as follows: 2, event based on limited circumstatntial evidence; 3, additional reference desired to firm up the time of occurrence or intensity; 4, occurrence time and intensity information is generally satisfactory, but we would like additional references as to areal extent; 5, the existing occurrence and intensity information is considered to be satisfactory."
Reference:
Scientific Committee on Oceanic research (SCOR) 1983: Prediction of El
Niño. Proceedings No. 19 Paris. Annex VI, SCOR WG 55 47-51.