Applications of the NERC MST radar facility in mesoscale studies

Abstract

The NERC radar facility located near Aberystwyth (52.4° N, 4.1° W) was established for remote sensing of the structure and dynamics of the mesosphere, stratosphere and troposphere; hence the name MST radar. The facility records scatter and reflection from metre-scale irregularities in refractive index produced by atmospheric waves and turbulence. The measurement of the three-dimensional wind field at tropospheric and lower stratospheric heights represents the primary capability of the facility and is expected to be particularly useful in short-range local weather forecasting operations. At the same time, the temporal and height resolution achievable lend themselves to studies of smaller-scale, time-varying phenomena, such as waves and turbulence. Particular attention has been paid to the characteristics and vertical propagation of mountain waves and inertia-gravity waves, and estimates made of the vertical flux of horizontal momentum associated with such waves, known to play a significant role in the large-scale atmospheric circulation. The turbulence associated with the dissipation of these waves, and also generated in the vicinity of jet streams, has also been examined. Quasi-specular reflection of radar waves associated with changes in temperature gradients has helped monitor the height and sharpness of the tropopause and also the structure of frontal zones. The technical capabilities of the facility and the continuity of data provided by its all-weather and extended operation have been shown to be well suited to both mesoscale meteorological and research applications.