SSF climate indices derived from PLSR
Climate indices for forecasting seasonal rainfall in south-west Western Australia, created using data from 1950 to 2012.
Steps to reproduce
Obtain NOAA extended reconstructed monthly sea surface temperature (SST) and NCEP Reanalysis monthly mean sea level pressure (SLP) data are from the NOAA PSD Climate Data Repository (https://www.esrl.noaa.gov/psd). Subset data to cover the Indian and Pacific Oceans: longitude 30 to 290 degrees and latitude -75 to 60 degrees. Calculate mean monthly rainfall for south-west Western Australia (SWWA). Use partial least squares regression to maximise the covariance between the SST / SLP data (lagged by one month) and mean SWW rainfall to calculate loadings that take values between -1 and 1 for each of the cells in the SST / SLP data and scores that are linear combinations of the SST/SLP data multiplied by the loadings. The loadings can be mapped to show the patterns of SST/SLP they identify. The scores provide a summary of the strength of the patterns through time and can be used as climate indices for forecasting seasonal rainfall in SWWA.