The WIGOS View of Observational Data Requirements for Weather, Climate and Water in the Coming Decades

With increasing demands for weather- and climate related services and improved prediction capabilities comes a growing demand for observational data on which these services are and will be built. This demand is being addressed by a number of observing systems, both conventional and space-based, developed and operated by a heterogeneous mix of national and international entities operating under various inter-related coordination mechanisms. In order to facilitate the planning of future observing systems intended to contribute to what is already a complex ecosystem, WMO maintains the so-called Rolling Review of Requirements (RRR) under the umbrella of the WMO Integrated Global Observing System (WIGOS). The RRR is a structured process for gathering, vetting and recording observational data requirements for application areas falling within the WMO sphere of interest in weather, climate and water, and for matching those requirements against planned and existing observing capabilities. In this presentation we will introduce this process, the so-called Rolling Review of Requirements, its various components, and some examples of output that may be of particular interest for both the short-term and long-term planning of  environmental satellite systems.