CentNet—A deployable 100-station network for surface exchange research

The consensus of an NCAR/EOL-hosted Workshop in 2007 was that a large sensor network would facilitate research in the biogeosciences, hydrology, and urban meteorology, in addition to more standard meteorology. Measurements that were listed as essential included turbulent fluxes and radiation. Example research topics include understanding turbulent flow over complex terrain, predicting convective initialization, characterizing the exchange of trace gases within a vegetative canopy, understanding above and subsurface water pathways, and the effect of the planetary boundary layer on pollution transport in an urban environment. All of these require a high-density network that could be redeployed multiple times in a year.

EOL is responding to this need by developing a network of at least 100 surface flux stations, that we call CentNet. Each station would measure standard meteorological variables, all components of the surface energy balance (including turbulence fluxes and radiation), atmospheric composition, and other quantities to characterize the surface. CentNet will minimize maintenance by use of redundant sensors and automatic cleaning systems. The data system already can cycle power on any sensor. Tower infrastructure will be designed to be lightweight, easily deployed, and with a minimal set-up footprint. RF communications are being utilized as much as possible to reduce cabling. The data system saves every sample on site to retain flexibility in data analysis.

Current development is focused on the use of sensor networks to increase spatial sampling at each station. When necessary, microprocessors are added to commercial sensors to provide any necessary control signals and to apply sensor calibrations. Two-way communication to each sensor is available to synchronize data streams and query sensor status. With this approach, CentNet is adaptable to a wide variety of research problems while keeping operations manageable.

We are now actively seeking input from potential users to guide development priorities.