Sodar Probing of Small-Scale Ordered Motions Appeared in the Atmospheric Planetary Boundary Layer

Abstract

This report describes a monostatic solar system performance conducted by the Radio Research Laboratories in Tokyo. Discussions are extended to the samples of observed records and to the results obtained from one-year continuous observations. It became clear that small-scale ordered motions play an important role in the structure of atmospheric temperature fluctuations in the planetary boundary layer.the scattering cross section * as a function of scatter angle * as follows :

Turbulent Layers Associated with a Critical Level in the Planetary Boundary Layer

“…The critical level is very effective to form such thin layers when wave amplitude of internal gravity waves is small. Multi-layers found in the stable PBL (Fukushima et al, 1974) could be explained as follows. If there exist several predominant internal gravity waves which have different phase velocities and accordingly different critical levels, the thin turbulent layers will be generated at each critical level.…”

“…Atlas and Metcalf (1970) and Metcalf and Atlas (1973) reported that those two are classified as large amplitude K-H waves and mini-K-H waves. In addition, there exist very thin echo layers which contain many mini-K-H billows and such layers form multi-layers frequently (Gossard et al, 1971;Fukushima et al, 1974). Thickness of the thin layers extend from a few to a few tens of meters.…”

Night Time Profiles of Temperature Fluctuations Deduced from Two-Year Sodar Observation

“…The Radio Research Laboratories (RRL), stimulated by his work, constructed the concrete paraboloidal antenna of 16m diameter in 1970 and have continued serial observations since then. Fukushima et al (1974) revealed from one-year continuous observation that appearance of atmospheric turbulence in the planetary boundary layer is likely to be associated with the small-scale ordered motions like atmospheric gravity waves and/or thermal plumes.…”