GEOWOW (GEOSS Interoperability for Weather, Ocean and Water) is the responds to call ENV.2011.4.1.3-1 Inter-operable integration of shared Earth Observations in the Global Context.The objectives of GEOWOW are to:• Propose and validate a distributed architectural model federating Earth observation and other Earth Science data holdings, including specific communities’ infrastructures, and put this model forward as the European contribution to the GEOSS Common Infrastructure (GCI) and its evolution toward a wider GEOSS architecture;• Develop innovative methods for harmonized access and use of heterogeneous data, services, and models to foster the sharing of knowledge among multiple disciplines, and the more integrated assessment and understanding necessary to advance global sustainability research;• Contribute to the GCI interoperability, standardisation and operability via developments and evolution;• Develop and support services for data dissemination, access, use (and processing) for the selected SBAs, contributing to the development of assessment tools and monitoring methods for sustainable development;• Establish, harmonise and promote data sharing and usage procedures consistent with the GEOSS Data Sharing Implementation Guidelines, and contribute to the development of the GEOSS Data CORE.• Provide harmonized and fast data access for meteorological hazards/extreme events, e.g., floods, including pre-processing services aimed at making the data of immediate use;• Deploy an e-infrastructure giving access to in-situ and satellite data as needed by hydrological application and Run-off process;• Support and enhance the access to in-situ and satellite ocean observations, to information on threats to ocean ecosystems, and to key ocean forecasts and projections - for research and assessment.A particular focus will be on supporting inter-disciplinary interoperability and on the use of semantics for enhanced discovery of data in the selected SBAs’ domains.