of the goals of its sponsors. This includes recommendations for phased implementation. The Panel also aids in the development of strategies for evaluation and evolution of the system and of its recommendations, and supports global ocean observing activities by interested parties through liaison and advocacy for the agreed observing plans. OOPC recognizes the need for sustainable ocean observations, and the increased need to connect to societal issues in the coastal zone. OOPC's role has evolved to oversee the ocean component of the GCOS, and the physical variables for GOOS, while defining long-term observing requirements for climate research of WCRP. Key activities of OOPC are: - Providing advice on scientific and technical requirements to the Joint WMO-IOC Technical Commission on Oceanography and Marine Meteorology (JCOMM), which is responsible for the coordination and implementation of platform-based observing system components; - Coordinate ocean observing networks that contribute to ocean ECVs by encouraging GOOS Regional Alliances (GRAs) and national commitments to global observing networks, and promoting common best practices and observing standards; - Reviewing and prioritizing requirements for sustained ocean observations of the physical Essential Ocean Variables (EOVs), and ocean ECVs, to engage the broad stakeholder community, to assess the readiness of observing technologies and adequacy of present global key variable observations, and to provide a source of technical advice on the development of national coastal and ocean observing requirements and observing system implementation plans. Terrestrial Observation Panel for Climate (TOPC) TOPC was set up to develop a balanced and integrated system of-in situ and satellite observations of the terrestrial ecosystem. The Panel focuses on the identification of terrestrial observation requirements, assisting the establishment of observing networks for climate, providing guidance on observation standards and norms, facilitating access to climate data and information and its assimilation, and promoting climate studies and assessments. Key activities of TOPC are: - Identification of measurable terrestrial (biosphere, cryosphere, and hydrosphere) properties and key variables (ECVs) that control the physical, biological and chemical processes affecting climate, and are indicators of climate change; - Coordination of activities with other global observing system panels and task groups to ensure the consistency of requirements with the overall programmes; - Assessing and monitoring the adequacy of terrestrial observing networks such as the Global Terrestrial Networks (GTNs), and promoting their integration and development to measure and exchange climate data and information; - Identification of gaps in present observing systems and designs to ensure long-term