Spatio-temporal precipitation climatology over complex terrain using a censored additive regression model

Int J Climatol. 2017 Jun 15;37(7):3264-3275. doi: 10.1002/joc.4913. Epub 2016 Nov 9.

Abstract

Flexible spatio-temporal models are widely used to create reliable and accurate estimates for precipitation climatologies. Most models are based on square root transformed monthly or annual means, where a normal distribution seems to be appropriate. This assumption becomes invalid on a daily time scale as the observations involve large fractions of zero observations and are limited to non-negative values. We develop a novel spatio-temporal model to estimate the full climatological distribution of precipitation on a daily time scale over complex terrain using a left-censored normal distribution. The results demonstrate that the new method is able to account for the non-normal distribution and the large fraction of zero observations. The new climatology provides the full climatological distribution on a very high spatial and temporal resolution, and is competitive with, or even outperforms existing methods, even for arbitrary locations.

Keywords: GAMLSS; censoring; climatology; complex terrain; daily resolution; precipitation.