SMS scnews item created by John Ormerod at Tue 14 Nov 2017 2205
Type: Seminar
Distribution: World
Expiry: 24 Nov 2017
Calendar1: 24 Nov 2017 1400-1500
CalLoc1: Carslaw 173
CalTitle1: A spatio-temporal mixture model for Australian daily rainfall, 1876--2015 Modeling daily rainfall over the Australian continent
Auth: jormerod@202-159-146-126.dyn.iinet.net.au (jormerod) in SMS-WASM

# Statistics Seminar: Prof. Sally Cripps -- A spatio-temporal mixture model for Australian daily rainfall, 1876--2015 Modeling daily rainfall over the Australian continent



Abstract:

Daily precipitation has an enormous impact on human activity, and the study of how
it varies over time and space, and what global indicators influence it, is of
paramount importance to Australian agriculture. The topic is complex and would
benefit from a common and publicly available statistical framework that scales to
large data sets. We propose a general Bayesian spatio-temporal mixture model
accommodating mixed discrete-continuous data. Our analysis uses over 294 million
daily rainfall measurements since 1876, spanning 17,606 rainfall measurement sites.
The size of the data calls for a parsimonious yet flexible model as well as
computationally efficient methods for performing the statistical inference.
Parsimony is achieved by encoding spatial, temporal and climatic variation entirely
within a mixture model whose mixing weights depend on covariates. Computational
efficiency is achieved by constructing a Markov chain Monte Carlo sampler that
runs in parallel in a distributed computing framework. We present examples of
posterior inference on short-term daily component classification, monthly intensity
levels, offsite prediction of the effects of climate drivers and long-term
rainfall trends across the entire continent. Computer code implementing the methods
proposed in this paper is available as an R package.


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