Capel Dewi Field Station
The Capel Dewi field site is located around 5 km east of Aberystwyth, Wales (52.42°N, 4.01°W), at the base of a small wooded valley. The site is maintained by the Rutherford-Appleton Laboratory and is the home of the UK Mesosphere-Stratosphere-Troposphere (MST) radar, a NERC national facility which is also used by the Met Office for operational wind measurements. The site is secure and has facilities for visiting scientists.
The MST Radar Facility also maintain surface meteorological measurements, a sky camera and a lidar ceilometer at the site. Surface wind measurements are made at the nearby Frongoch Farm, and the Met Office operate a GPS water vapour receiver at Capel Dewi.
The Atmospheric Science group is a major user of the MST radar facility and has a number of ancillary instruments that add to the science:
1. Boundary-layer wind profiler. This is a radar system working at a much higher frequency than the MST radar which measures vertical profile of winds and atmospheric structure down to 100 m altitude. It is part of the FGAM suite of mobile atmospheric instrumentation.
2. Ozone lidar. This lidar system is designed for measurements in the troposphere and lower stratosphere, from 5 to 15 km. It uses a Nd-YAG laser at 266 nm, with Raman cells to shift the transmitted wavelengths to 289, 299 and 316 nm.
3. Mobile boundary-layer ozone/aerosol lidar. This is another FGAM instrument, using similar principles to the fixed ozone lidar. It transmits five wavelengths, 266, 289, 299,316 and 355 nm, and measures ozone and aerosol profiles in the bottom 2 km of the atmosphere.
4. Water vapour/aerosol lidar. This uses Raman scattering from the atmosphere to measure profiles of N2 and water vapour, from which the humidity mixing ratio profile mat be readily derived.
5. SAOZ UV-Visible spectrometer. This is an instrument to monitor stratospheric ozone and nitrogen dioxide column totals, by measuring absorption features in the solar spectrum at twilight.
Click here to see a powerpoint file with more information about Capel Dewi.