Four themes (evapotranspiration, soil moisture, clouds and water vapour) are identified to develop global water cycle datasets.

WACMOS contributes to current international efforts by supporting scientists in ESA member countries to develop and validate novel and improved multi-mission based products to enhance currently available global water datasets maximizing the use of ESA data.

The short term objectives of the project include:

• Develop and validate a Product Portfolio of novel and/or improved multi-mission based geoinformation datasets at global and basin scales maximizing the use of ESA data and contributing the GEWEX efforts. WACMOS is focused on four Thematic Priorities described below and identified in close collaboration with the IGPO (International GEWEX Project Office);
• Explore ways to facilitate the integration of the final Product-Portfolio into models and data assimilation processes at different scales (e.g., run-off, water balance, flood risk, drought, climate) demonstrating its value for science and applications;
• Consolidate a potential Scientific Roadmap to advance towards the establishing of longterm coherent multi-source data records as a support to the GEWEX community as well as a solid user base in preparation of a potential future demonstration activity within the Data User Element.
• In the long-term the project aims at:
• Supporting GEWEX to set up solid scientific basis for the creation of coherent long-term datasets of water relevant geo-information exploiting synergies among past, existing and upcoming missions;
• Promote the concept of a Water Cycle Multi-mission Observation Strategy within the water community as an approach to build coherent long-term water relevant datasets where ESA data may play a key or substantial role.