A three-way model for interpolating for monthly precipitation values

Abstract

The methods studied are: 1) multiple discriminant analysis (MDA), which is based on empirical orthogonal functions (EOFs), 2) multiple linear regression (MLR), which is similar to Gandin's optimal interpolation, and 3) the normal ratio method. The MDA method is described in detail since it represents a novel use of EOF. The MDA method is found to provide the most skillful interpolation for the sparse 19th-century network of stations and for the summer (June-July-August) season, which is characterized by mesoscale convection. A median model based on the three individual models is analyzed and found to be superior to the individual methods for the 20th-century network except for the summer season. -from Author