The flux tower at Basel Klingelbergstrasse (264 m a.s.l.) has one of the longest urban CO2 flux records worldwide (permanently operated since 2004). A short summary of the history can be found in Feigenwinter et al. (2017): Insights from more than ten years of CO2 flux measurements in the city of Basel, Switzerland.
The tower is equipped with up to date EC systems and extensive additional meteorological instruments for standard meteorology (air temperature, humidity, wind, pressure, precipitation), and a four-component radiometer to account for all terms of the urban radiation balance, including a roof based sun-tracker equipped with a pyrheliometer (direct beam) and a shaded pyranometer (diffuse radiation). The height of the Urban Boundary Layer is monitored by a ceilometer.
The ICOS relevant measurement programme at Basel is organised as follows:
- Greenhouse gas measurements (CO2, H2O) using the eddy covariance technique
- Urban boundary layer with ceilometer
- Soil water content in the near surroundings of the flux tower