The concept of Ruisdael Observatory is optimized to address the challenges the atmospheric sciences face in a very diverse and heterogeneous setting. The Dutch emission landscape is a perfect example of the situation expected to develop in many urbanized regions of the world. Emissions of CO2 are strongly linked to people’s daily activities. Food production close to urban areas incurs large emissions of methane from livestock husbandry, while intensive agriculture typically comes with high emissions of ammonia. Industry, gas and oil production, and freight transport are all of vital economic importance, but each comes with their own emissions. Ultra-fine aerosol particles are directly emitted by traffic and industrial sources, but also result from new particle formation in the atmosphere. Together this constitutes a typical ‘urban landscape’, where interactions between processes are expected to function in a different way than in more homogeneous landscapes, because of the small scale of heterogeneity.
Present facilities to study atmospheric processes lack the ability to routinely link data and models at different spatial and temporal scales, which is essential for the improvement of the reliability of climate change predictions and sink/source attribution. This gap is filled by the Ruisdael Observatory. Observations and models are merged in real time to extrapolate the spatial representativity of local observations and form a virtual laboratory for studying multi-scale processes in atmospheric chemistry and physics. By doing so the accuracy of climate, weather and air quality models is significantly improved. This merger of observations and models within Ruisdael involves:
- the deployment of sensor networks for attribution of spatial variability of aerosols, greenhouse and other trace gases to sources and sinks, incl. in situ support for the use of satellite data;
- transforming measurement profiles from 1D vertical profiles of wind, temperature, humidity, clouds and rain to true 3D volume scans to get a realistic representation of the atmospheric variability and dynamics influencing the small-scale processes;
- introducing the observational capability to study fundamental small-scale processes;
- simultaneous coupling of models to the observational data acquired at different spatial and temporal scales on ground, in the atmosphere as well as from space.
The current Ruisdael Observatory is an advancement and extension of existing facilities which combine in-situ measurement and advanced ground-based remote sensing at multiple locations in the Netherlands. The backbone of Ruisdael Observatory consists of four fixed state of the art equipped measurement stations in Cabauw, the city of Rotterdam, the forested area of Loobos and the coastal area around Lutjewad. The observatory also operates mobile platforms including a wide variety of sensors and remote sensing devices, the computational capability for real-time Large-Eddy simulations and a world class facility to collect and store all data obtained from the various sites. Early 2022, the well equipped Amsterdam Atmospheric Monitoring Supersite and Veenkampen rural grassland site joined the Ruisdael Observatory. Both sites complement the original stations of the Ruisdael Observatory. Moreover, Ruisdael Observatory is strongly embedded in the European Research Infrastructure Consortia ICOS and ACTRIS.
Whereas Ruisdael Observatory focuses on measuring and modelling the atmosphere over land and urban areas, the aim is to extend the current infrastructure over the North Sea in the coming years. The North Sea is a dominant factor in the climate of Western Europe and is facing a number of profound challenges in the coming decades due to climate impacts, intensification of shipping and increasing human activity offshore, including expanding wind and solar energy farms. These changes in seascape will influence weather, climate and pollution levels over the North Sea and adjacent land. The extended observatory will enlarge our understanding of how the North Sea is affecting today’s and future atmospheric conditions. Data storage will be provided by an update of the current Ruisdael data portal securing the connection to observational facilities of public agencies and universities and EU infrastructures ACTRIS and ICOS.