A non-linear statistical downscaling model: ENSO impact on precipitation over New Caledonia
Martin Fischer, Boris Dewitte and Luc Maîtrepierre
A new multivariate non-linear non-parametric regression method, named MARS, is used in a statistical downscaling problem for simulating New Caledonian rainfall anomalies induced by ENSO. The use of a non-linear method was motivated by wavelet analyses, pointing to a complex interaction between interannual and intraseasonal rainfall variability.
The proposed method is very flexible and computationally efficient. It can be applied to a wide range of problems and its use is not limited to spatial downscaling applications. Furthermore the method provides great potential for comprehensive diagnostics of multivariate problems in climate research.
It is shown that this method is appropriate for taking into account the asymmetry between El Niño and La Niña periods and to some extent, the type of El Niño.