"The first level of GMES applications in the marine area is mostly represented by the ""upstream"" services of the MCS (e.g. MyOcean). Unfortunately, the current MyOcean offering of products and services for biogeochemistry has limitations that prevent a full uptake by the potential users. The present project proposes to address these issues through a range of R&D activities designed to offer a set of solutions that shall benefit the Marine Core Service beyond 2015. The outcomes of the project are expected to benefit both the upstream and downstream services of the MCS. To achieve this, the OSS2015 team will conduct R&D work in three areas:o The derivation of 3-D and 4-D representations of biogeochemical variables from the integration of gliders and floats in situ data and EO satellite data into cutting-edge numerical biogeochemical and bio-optical models. The models, assimilation schemes and output products from the models will be tested at two pilot sites (Mediterranean and North Atlantic)o The generation and validation of satellite derived global time series of advanced biogeochemical products (POC, NPP, PFT, PSD) for carbon cycle science.o The implementation of a prototype platform of ""on-demand"" services for product generation and distribution.This system of services will be tested and demonstrated with the new biogeochemistry products developed during the project.OSS2015 will also analyse the social and economical benefits and value of the products and services generated by the project.The OSS2015 team is a good balance of ten partners from six scientific research institutionsand four SMEs and is designed to cover the needs of both science users and users interested in more applied services. A strong emphasis will be put on dialogue and interaction with users in order to identify their actual needs and adapt the OSS2015 services accordingly whenever possible."