The Southern Oscillation Index is defined as the standardized difference between barometric readings at Darwin, Australia and Tahiti.
Arguments
- use_cache
logical option to save and load from cache. If `TRUE`, results will be cached in memory if `file` is `NULL` or on disk if `file` is not `NULL`.
- file
optional character with the full path of a file to save the data. If `cache` is `FALSE` but `file` is not `NULL`, the results will be downloaded from the internet and saved on disk.
Value
Date: Date object that uses the first of the month as a placeholder. Date formatted as date on the first of the month because R only supports one partial of date time
Month: Month of record
Year: Year of record
SOI: Southern Oscillation Index
SOI_3MON_AVG: 3 Month Average Southern Oscillation Index