DAILY RAINFALL DOMAINS IN MALLORCA

A Pearson Product Moment Correlation matrix for four years of daily ra infall from 96 sites on the island of Mallorca has been used to derive and map correlation fields and construct composite correlation fields for different parts of the island based on previously defined daily r ainfall affinity areas. Significant variations in rainfall organisatio n over the island are revealed. These reflect the dominance of uplift and exposure by upland areas in the generation of rainfall, evidenced in strongly anisotropic correlation fields. Further anisotropy along l owland coasts normal to the relief trend indicate the role of local ra infall generation along sea-breeze fronts. Near isotropic fields for c entral island locations highlight the importance of local convection a nd local convergence between opposing sea breeze systems and inland co nvection. Linear correlation distance-decay trends are determined for the island and for the predetermined rainfall affinity areas, includin g estimates of distance-decay rates along field axes. A suite of expon ential cone functions is derived to model the empirically observed fie lds, representing their typical bidimensional structure. Use of the fi tted cones to model a 'typical' rainfall day, where the rainfall distr ibution mimics quite closely the longer term average, yields quite goo d results and suggests that their use may be more appropriate than app lying more conventional general interpolation techniques in the mappin g of spatial rainfall distributions.