IEEE JOURNAL OF SELECTED TOPICS IN APPLIED EARTH OBSERVATIONS AND REMOTE SENSING,VOL. 5, NO. 6, DECEMBER 2012 1591 Foreword to the Special Issue on Interoperability Architectures and Arrangements for Multi-Disciplinary Earth Observation Systems and Applications U NDERSTANDING and managing the Earth environment requires multi-disciplinary capabilities—often at a global scale—and the formation and operation of distributed, multidis- ciplinary collaborative teams. This is a social and cultural chal- lenge as well as a science and technology one. To meet this need, there have recently been a number of interoperability initiatives and programs which focus on improving access to, and usability of, remote sensing and other Earth Observation resources for policy making and decision support. In a large scale integrated system, System of Systems (SoS) components can operate independently to offer products or services satisfying the requirements of various customers. A holistic technology architecture within a complex “ecosystem” (like the Earth Observation domain) is comprised of heteroge- neous and multi-disciplinary capabilities and resources. These capabilities are either managed at the enterprise level by big organizations (e.g., World Meteorological Organisation, United Nations, US Environmental Protection Agency, European Environment Agency, and so on) or at the individual level by scientists in their laboratories and at their desktops or through social networks (e.g., individual blogs, Wiki sites). A successful architecture must take a comprehensive and inclusive approach to all of these resources and tools. Such a global scale SoS approach is essential to study and address global challenges, including: poverty reduction, food security and agricultural production, integrated water resource management, natural re- source management, migration, urbanization, land degradation, climate change, and safe and reliable energy supply. The papers in this special issue address recent breakthroughs in science and technology useful for implementing multi-disci- plinary interoperability. They include the introduction and dis- cussion of new or advanced multi-disciplinary interoperability solutions, as well as the description of innovative multi-disci- plinary systems and applications. Zell et al. describe a user-driven approach to determining critical Earth Observation priorities for societal benefit. At the overall architectural level, Vaccari et al. address integrative re- search needs introducing the brokering approach experimented by the EuroGEOSS project. In the same line, mediation-based architectures are recognized as important for achieving inter- disciplinary decision support tools and applications (such as Web portal) by Fegraus et al., Kuo et al., Rodila et al., and Digital Object Identifier 10.1109/JSTARS.2012.2234234 D’Amore et al. Open standards, web services for discovering and accessing data and sensor products, and geo-processing ser- vices to use and compose them are identified as important tech- nologies to implement multi-disciplinary applications—by Bai et al., Blodgett et al., Chiu et al., Shi et al., Zeng et al., and Zhang et al., while Chen et al., Kussul et al., and Rodilla et al. focus particularly on the capabilities offered by the Grid and Cloud computing to geo-processing. Several GEOSS (Global Earth Observation System of Sys- tems) related projects and developments are presented, e.g., EuroGEOSS, enviroGRIDS, GMOS, EnerGEO, and AIP. These papers cover significant cross-discipinary areas and applications, including: debris flow (Chiu et al.), air quality (D’Amore et al.), water resources impact forecasting (Danner et al.), agriculture (Falzon et al., Fegraus et al., Melton et al.), flood monitoring (Kussul et al.), forestry (McInerney et al., Vaccari et al.), and environmental impact of power systems (Menard et al.). STEFANO NATIVI, Guest Editor National Research Council of Italy (CNR) Rome, Italy stefano.nativi@cnr.it MAX CRAGLIA, Guest Editor European Commission, Joint Research Centre Institute for Environment and Sustainability Ispra, Italy massimo.craglia@jrc.ec.europa.eu GARY GELLER, Guest Editor NASA Jet Propulsion Laboratory Pasadena, CA USA gary.n.geller@jpl.nasa.gov MIKE JACKSON, Guest Editor University of Nottingham Nottingham, U.K. mike.jackson@nottingham.ac.uk SIRI JODHA SINGH KHALSA, Guest Editor National Snow and Ice Data Center (NSIDC) Boulder, CO USA sjsk@nsidc.org 1939-1404/$31.00 © 2012 IEEE