A novel approach to precipitation series completion in climatological datasets:: application to Andalusia

Complete monthly series of precipitation data have been generated for 932 stations run by the Instituto Nacional de Meteorologia (INM) in Andalusia (Andalucia, southern region of Spain) and some adjacent areas for the period 1961-2000 using a new method for the estimation of missing data. The proposed method fills in the gaps in the climatological series for a target station using precipitation data from neighbouring stations with a similar precipitation pattern. Particular emphasis is made in the consideration of the precipitation data uncertainty. A set of possible estimates for the missing data are obtained assuming a linear relationship between the target station and the selected neighbour stations. The final imputed value is the median of the previously evaluated estimates distribution. This approach also provides the uncertainty of the missing data estimate. As an application, the suggested approach is used to obtain a precipitation map of Andalusia, as well as the average annual series for the examined period. Copyright (C) 2008 Royal Meteorological Society.