Abstract

Boundary layer research has been increasingly hampered by the lack of sensors that can economically provide accurate high spatial and temporal resolution wind measurements covering large atmospheric volumes. In particular, measurements of the turbulent fluctuations of the wind with better than 50 m spatial resolution covering volumes of a few km³/sec to distances of 10 km are needed to estimate weakly correlated turbulent quantities (e.g. momentum fluxes <u'w'>, <v'w'>). These measurements are also needed to test model parameterizations and to initialize model runs for Large Eddy Simulation (LES) models. These models have recently been used to provide detailed insights into fundamental boundary layer processes, particularly non-steady-state, transitional, and intermittent processes. Of particular interest to NOAA are the improvement of vertical resolution in the boundary layer entrainment zone, higher resolution observations of the nocturnal and baroclinic (neutral or shear-driven) boundary layers, day/night boundary layer transition processes, and observation of the ocean-atmosphere boundary layer. Other interests requiring new instrument capabilities are: the development of techniques for the direct measurement of fluxes of moisture, momentum, and chemical species, the measurement of vertical velocities and ice crystal fall speeds in cirrus clouds and the impact of shear on cloud morphology, the measurement of synoptic scale divergence and vorticity, and the behavior of complex terrain flows.

© 1995 Optical Society of America