A Daily Rainfall Model for Multiple Sites for Use in Statistical Downscaling

• Activity Number: 260 - SPEED: Environmental Statistics Methods and Applications, Part 2
• Type: Contributed
• Date/Time: Monday, July 29, 2019 : 3:05 PM to 3:50 PM
• Sponsor: Section on Statistics and the Environment
• Author(s): Yiming Liu* and Ernst Linder
• Companies: University of New Hampshire and University of New Hampshire
• Keywords: Daily precipitation; Zero-truncation; GAMLSS; Statistical downscaling

Abstract

Traditionally, precipitation at a daily scale was examined in a two-stage approach: one model for the rain occurrence process and another one for the rain amount process. This study unifies the two processes by using a power-transformed and truncated normal distribution. First we use a Generalized Additive Model for Location, Scale, and Shape (GAMLSS) to estimate a full-distributional climatology of daily precipitation over multiple sites in New England. Then, utilizing corresponding regional climate model information, we develop a statistical downscaling approach for multiple sites that is rooted in the quantile-matching framework and enables projections of future precipitation patterns based on the selected daily rainfall model.