The last GAUGE tall tower was successfully equipped with greenhouse gas measurement instrumentation on the 29th January 2014 by a small team from the University of Bristol, Dickon Young, Dan Say and Ann Stavert, and Carole Helfter (CEH).
The Bilsdale tall tower (54°21.48’ N, 1°9.02’ E) is in a remote area of the North York Moors National Park and is the first monitoring site in the northeast region of England. The closest large conurbations are York and Middlesbrough, located 30 miles south and 16 miles northeast, respectively. The tower is on a high plateau overlooking green valleys used mainly for livestock (sheep and cattle).
The Cavity Ring – Down Spectrometer (CRDS, Picarro G2401), measuring CO2, CH4 and CO, and a Gas Chromatograph – Electron Capture Detector (GC-ECD), measuring N2O and SF6, are located at the base of the 290.5 m high telecommunications tower. There are intakes at 48, 108 and 248 m on the tower. The CRDS makes high frequency measurements for 20 minutes at each height, while the GC-ECD only measures at a single intake. Calibration and standard tanks are measured periodically and ensure the new measurements are comparable to those made at other sites within the GAUGE and UK DECC networks.
A return visit is planned in the near future to modify CRDS drying method and to connect a third CRDS calibration cylinder along with a range of standard site checks. Routine maintenance of the site will be conducted by Carole Helfter (CEH) with the support of University of Bristol staff.
Some of the first CO2 measurements from the tower at different heights (red: 248 m, yellow: 108 m, green: 48 m). Concentrations at different heights are often quite similar, indicating well-mixed situations, but sometimes (mostly at night) distinct concentration layers, stratification, can be seen.