Merged Statistical Analyses of Historical Monthly Precipitation Anomalies Beginning 1900

Reconstructions use the available historical data and statistics developed from the modern satellite-sampled period to analyze variations over the historical pre-satellite period. This paper documents the latest in a series of precipitation reconstructions developed by the authors.

Although the reconstruction principle is still the minimization of mean-squared error, this latest reconstruction includes the following three major improvements over previous reconstructions: (i) an improved method that first produces an annual first guess, which is then adjusted using a monthly increment analysis; (ii) improved use of oceanic observations in the annual first guess using a canonical correlation analysis; and (iii) reinjection of gauge data where those data are available.