Module A is concerned with (1) improving estimates of the present climate state and (2) the way these estimates are being used as initial conditions for decadal predictions using coupled climate models.

The first task is thus concerned with improving initial conditions of coupled climate models by obtaining and improving estimates of the climate state of each component of a coupled climate model and improving the assimilation procedures used to obtain those estimates. Performing decadal predictions fundamentally requires starting a coupled climate model from best-possible initial conditions resembling the observed climate state. This requires to have a good estimate of the current climate state.  

The second task is to work on initialization procedures to further improve the use of climate state estimates as initial conditions and to improve the resulting predictions. To bring the model close to these climate state estimates, observations need to be incorporated into the model, which can be done through different initialization strategies. The initialization methods that have been tested so far lead to different prediction results. It is therefore necessary to improve the initialization strategies hitherto used, and to investigate the sensitivity of the hindcasts and forecasts to different choices of initialization.            

The work program in Module A is oriented along these objectives and involves four contributions, which address individual aspects as lined out in the objectives, as listed on the right.