Atmospheric boundary-layer structure from simultaneous SODAR, RASS, and ceilometer measurements

A comparison of the determination of boundary-layer structures by a SODAR, by a RASS, and by a ceilometer is presented. One important structure is the mixing-layer height (MLH). The comparison is focused on 3 days with an evolution of a convective boundary layer over a larger city in Germany. The three instruments give information that partly agree and partly complement each other. By this, a picture of the diurnal evolution of the vertical structure of this urban boundary layer is presented. The ceilometer gives information on the aerosol content of the air and the RASS provides a direct measurement of the vertical temperature distribution in the boundary layer. The RASS and the ceilometer add information on the moisture structure of the boundary layer that is not detected by the SODAR. On the other hand this comparison validates known techniques by which the MLH is derived from SODAR data. Especially the temperature information from the RASS agrees well with lifted inversions derived from the analysis of the SODAR data. The ceilometer, being the smallest instrument, has a potential to be used in future MLH studies.