hadisst1: SST data.
In cmarmstrong/rnino: Nino indices

Description Usage Arguments Details Value Functions

View source: R/nino.R

Download SST data from <https://www.esrl.noaa.gov/psd/gcos_wgsp/Timeseries/>.

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hadisst1(index = c("nino12", "nino3", "nino34", "nino4"), anom = FALSE)

hadsst3(index = c("nino12", "nino3", "nino34", "nino4"))

`index`	Character. Indicates the nino index, possible values are 'nino1+2', 'nino3', 'nino3.4', or 'nino4'. Default 'nino1+2'.
`anom`	Logical. Indicates if the index should be anomalies (deviation from mean) or absolute values. Only available for HadISST1; default FALSE.

Details copied from <https://climatedataguide.ucar.edu/climate-data/nino-sst-indices-nino-12-3-34-4-oni-and-tni>

The numbers of the Ni\~no 1,2,3, and 4 regions correspond with the labels assigned to ship tracks that crossed these regions.

Ni\~no 1+2 (0-10S, 90W-80W): The Ni\~no 1+2 region is the smallest and eastern-most of the Ni\~no SST regions, and corresponds with the region of coastal South America where El Ni\~no was first recognized by the local populations. This index tends to have the largest variance of the Ni\~no SST indices.

Ni\~no 3 (5N-5S, 150W-90W): This region was once the primary focus for monitoring and predicting El Ni\~no, but researchers later learned that the key region for coupled ocean-atmosphere interactions for ENSO lies further west (Trenberth, 1997). Hence, the Ni\~no 3.4 and ONI became favored for defining El Ni\~no and La Ni\~na events.

Ni\~no 3.4 (5N-5S, 170W-120W): The Ni\~no 3.4 anomalies may be thought of as representing the average equatorial SSTs across the Pacific from about the dateline to the South American coast. The Ni\~no 3.4 index typically uses a 5-month running mean, and El Ni\~no or La Ni\~na events are defined when the Ni\~no 3.4 SSTs exceed +/- 0.4C for a period of six months or more.

ONI (5N-5S, 170W-120W): The ONI uses the same region as the Ni\~no 3.4 index. The ONI uses a 3-month running mean, and to be classified as a full-fledged El Ni\~no or La Ni\~na, the anomalies must exceed +0.5C or -0.5C for at least five consecutive months. This is the operational definition used by NOAA.

Ni\~no 4 (5N-5S, 160E-150W): The Ni\~no 4 index captures SST anomalies in the central equatorial Pacific. This region tends to have less variance than the other Ni\~no regions.

The datasets provide the sea surface temperature (SST) used to compute the nino indices. The HadISST1 is an interpolated dataset with global and smoothly varying values, provided and maintained by the Met Office Hadley Center. HadSST3 is the most recent version of the Hadley data, and corrects many biases of the previous data. It is not (yet) interpolated, but offers multiple realizations of the data that facilitate analysis of uncertainty.

Dataframe. Both datasets have a year and month column. HadISST1 will have a single value column. HadSST3 will have 100 value columns, each representing a single realization. A value of -99 indicates a missing value.