This section describes in detail the work planned to achieve the objectives of the GEMS project up to its first 18 months in operation. By design, during this phase of the development, the main interactions will be bilateral between the Production team on the one hand, and the separate sub-Projects GHG, GRG, AER, and RAQ on the other hand. The goal of the bilateral arrangements are to build and validate the model appropriate for each element of the trial assimilation systems. A prime concern of the Production team will be to acquire the necessary data and build the three trial assimilation systems by the end of year one, and then begin the production of the reanalyses at the beginning of year two. In parallel, the science teams will develop new capabilities for inversion, verification, validation and so on.

This first phase of the implementation plan is designed to minimise the impact of delays in one sub-Project on the other-sub-Projects, and thus allow for catch-up should that prove necessary. The only interdependencies between the main sub-Projects are with the PRO project as noted above.

The material in the following sub-sections sets out the detailed implementation plan for each of the five sub-Projects active in the period: GHG, GRG, AER, RAQ, PRO. Within each sub-section the detailed plan is broken down into workpackages (WPs) which follow the logical phases of the project during this period, and include management of the project and assessment of progress and results. Some of the sub-Projects have chosen to give an overall narrative of the whole four-year plan before describing the individual work packages in their domain, as they feel this gives a context for their plans.

For each sub-Project, the work planning includes

o Workpackage list

· Deliverables list ;

· Description of each workpackage with a narrative, followed by the WP table

03-08-2005