GEOS-S2S-1 Production System

The GMAO produces experimental near real time climate (seasonal-to-interannual or S-I) forecasts with the GEOS-5 atmosphere-ocean general circulation model (AOGCM). These forecasts and a related set of hindcasts are displayed at the GMAO Experimental Forecasts page. They are also provided to the North American Multi-Model Ensemble (NMME) prediction project, as well as to other national (IRI) and international (APCC) ensemble seasonal forecasting efforts. In addition, the ocean initial conditions for temperature and salinity are provided to the Real Time Multiple Ocean Reanalysis Intercomparison project to help assess the uncertainties in the subsurface ocean analyses. By providing the forecasts and analyses to the external community we are able to assess the quality of the GEOS-5 forecast system in the context of other state-of-the art systems and we benefit from having various external users providing a more comprehensive evaluation our system.

Here we describe the S-I forecasts and prediction system used to produce them. We note that this same system (with some modifications) was also used to produce a set of decadal predictions as part of the GMAO contribution to CMIP-5. In addition, this system is currently being used to produce sea ice forecasts. The description of the GEOS-5 S-I production system is organized into descriptions of the GEOS-5 AOGCM, the analysis systems used to generate the initial conditions, and the methodology used to produce the ensemble members. We also provide a description of the current development version of the GEOS-5 prediction system to give users of our current products a sense of the improvements targeted to go into future versions of the S-I production system.