Towards a Multi-analysis Ensemble

LUCINI, MARÍA MAGDALENA; SHEPHERD, THEODORE; POLAVARAPU, SAROJA; MCFARLANE, NORMAN

Montreal, Canadá

Congreso; MOCA 09 , IAMAS /IACSO/ IACS Joint Assemmbly; 2009

Due to the sparsness of observations within  polar regions, the identification of model errors and uncertainties in this region is a difficult task. Using an ensemble of model analyses is one approach to quantifying those errors and uncertainties and this information may ultimately lead to better forecasts. In this work we use an ensemble of middle atmospheric analyses from different operational and research centers and observations of temperature and ozone, all of them specially produced for the International Polar Year 2007-2008 (IPY)  project, to produce a best estimate of  the state of the atmosphere in the polar region.  Our present goal is to develop a statistical framework to obtain optimal estimates of the weights assigned to each ensemble member contributing temperature and ozone time series for the late winters and springs of 2007 and 2008 in the lower stratosphere. We shall present the statistical methodology used to obtain optimal estimates of the weights and the different approaches one may take to detrend the time series involved, along with some preliminary results.