P91  Bayesian Assessment of Horizontal Resolution in a Nested-Domain WRF Simulation

Mesquita, M.d.S., Bjerknes Centre for Climate Research and Uni Research, Norway, dlandsvik, B., Bjerknes Centre for Climate Research and Institute of Marine Research, Norway, Bruyere, C.L., The National Center for Atmospheric Research, USA, and Sandvik, A.D. Bjerknes, Centre for Climate Research and Institute of Marine Research, Norway

The fast-paced development of state-of-the-art limited area models and faster computational resources have made it possible to create simulations at increasing horizontal resolution. This has led to a ubiquitous demand for even higher resolutions from users of various disciplines.

This study revisits one of the simulations used in marine ecosystem projects at the Bjerknes Centre. We present a fresh perspective on the assessment of these data, related more specifically to: a) the value added by increased horizontal resolution; and b) a new method for comparing sensitivity studies.

The assessment is made using a Bayesian framework for the distribution of mean surface temperature in the Hardanger fjord region in Norway. The normal and inverse-gamma distributions are applied to the conjugate prior distribution. Population estimates are calculated based on samples from the joint posterior distribution generated using a Monte Carlo procedure.

The Bayesian statistical model is applied to: a) output data from the Weather Research and Forecasting (WRF) model at three horizontal resolutions (9, 3 and 1 km); b) Station-based observational data; and c) ERA Interim and NCEP NCAR Reanalysis. The period considered in this study is from 2007 to 2009, for the months of April, May and June.