Augmenting long-term ecosystem-atmosphere observations with multidisciplinary intensive campaigns aims at closing gaps in spatial and temporal scales of observation for energy- and biogeochemical cycling, and at stimulating collaborative research.

ScaleX is a collaborative measurement campaign, co-located with a long-term environmental observatory of the German TERENO (TERrestrial ENvironmental Observatories) network in mountainous terrain of the Bavarian Prealps, Germany. The aims of both TERENO and ScaleX include the measurement and modeling of land-surface atmosphere interactions of energy, water, and greenhouse gases. ScaleX is motivated by the recognition that long-term intensive observational research over years or decades must be based on well-proven, mostly automated measurement systems, concentrated on a small number of locations. In contrast, short-term intensive campaigns offer the opportunity to assess spatial distributions and gradients by concentrated instrument deployments, and by mobile sensors (ground/airborne) to obtain transects and three-dimensional patterns of atmospheric, surface, or soil variables and processes. Moreover, intensive campaigns are ideal proving grounds for innovative instruments, methods and techniques to measure quantities that cannot (yet) be automated or deployed over long time-periods. ScaleX is distinctive in its design that combines the benefits of a long-term environmental monitoring approach (TERENO) with the versatility and innovative power of a series of intensive campaigns, to bridge across a wide span of spatial and temporal scales. This contribution presents the concept and first data products of ScaleX-2015. The second installment of ScaleX is set for the summer 2016 and periodic further ScaleX campaigns are planned throughout the life-time of TERENO. This paper calls for collaboration in future ScaleX campaigns, or by using our data in modeling studies. It is also an invitation to emulate the ScaleX concept at other long-term observatories.