Interpolation Methods for the Climate Atlas

For the production of the maps in the Climate Atlas 1981-2010 (Klimaatatlas 1981- 2010) the entire interpolation facility at KNMI has been upgraded. This facility contains the whole chain from the processed measurement data in the database to various map products. Pre-processing of the data is done according to research done by KNMI division KS-KA. Starting in 2009 research has been conducted to develop optimal interpolation methods, new interpolation applications, and new methods for presenting and downloading interpolated data. A Geo Spatial Interpolation Environment (GSIE) was developed for the interpolation of maps. GSIE uses R, software for statistical computing (R-Project, 2009). All maps on the website and in the book version of the Climate Atlas are produced using the renewed interpolation algorithms in GSIE. In this report KNMI has documented the applied methods, the scientific basis and “recipes” to produce these maps.