1Norwegian Meteorological Institute, Oslo, 0313, Norway
2European Centre for Medium-range Forecasts, Reading, UK
3Norwegian Institute for Air Research, Kjeller, Norway
Received: 06 Apr 2016 – Discussion started: 31 May 2016
Abstract. We show how factorial regression can be used to analyse numerical model experiments, testing the effect of different model settings. We analysed results from a coupled atmosphere–ocean model to explore how the different choices in the experimental set-up influence the seasonal predictions. These choices included a representation of the sea ice and the height of top of the atmosphere, and the results suggested that the simulated monthly mean air temperatures poleward of the mid-latitudes were highly sensitivity to the specification of the top of the atmosphere, interpreted as the presence or absence of a stratosphere. The seasonal forecasts for the mid-latitudes to high latitudes were also sensitive to whether the model set-up included a dynamic or non-dynamic sea-ice representation, although this effect was somewhat less important than the role of the stratosphere. The air temperature in the tropics was insensitive to these choices.
Revised: 27 Sep 2016 – Accepted: 03 Oct 2016 – Published: 10 Nov 2016
Benestad, R. E., Senan, R., and Orsolini, Y.: The use of regression for assessing a seasonal forecast model experiment, Earth Syst. Dynam., 7, 851-861, doi:10.5194/esd-7-851-2016, 2016.