Allan, R J; Nicholls, Neville; Jones, Philip D; Butterworth, I J (1991): A further extension of the Tahiti-Darwin SOI, early SOI results and Darwin pressure. Journal of Climate, 4, 743-749, https://doi.org/10.1175/1520-0442(1991)004%253C0743:AFEOTT%253E2.0.CO;2
Ropelewski, C F; Jones, Philip D (1987): An extension of the Tahiti-Darwin Southern Oscillation Index. Monthly Weather Review, 115, 2161-2165, https://doi.org/10.1175/1520-0493(1987)115%3C2161:AEOTTS%3E2.0.CO;2
Latitude: 0.000000 * Longitude: 0.000000
Date/Time Start: 1866-01-15T00:00:00 * Date/Time End: 1997-12-15T00:00:00
Minimum Elevation: 0.0 m * Maximum Elevation: 0.0 m
The SOI is defined as the normalized pressure difference between Tahiti and Darwin. There are several slight variations in the SOI values calculated at various centres. Here we calculate the SOI based on the method given by Ropelewski and Jones (1987). The reader is also referred to Allan et al. (1991) and Können et al. (1998) for details of the early pressure sources and methods used to compile the series from 1866 onwards.
1584 data points