Refractivity Profile Assimilation Model for the Atmospheric Boundary Layer
Abstract
Anomalous propagation of microwave radiation in the Atmospheric Boundary Layer (ABL) at near horizontal elevation angles due to small vertical gradients in the refractive index of the air can significantly enhance or degrade the performance of microwave systems. The modelling of microwave propagation under anomalous ducting conditions requires an accurate knowledge of the vertical profile of atmospheric refractivity, which can be derived from profiles of pressure, temperature and moisture. This paper develops the Monin-Obukhov similarity theory of the atmospheric surface layer by blending it into the mixed layer, which lies above it and which forms the bulk of the atmospheric boundary layer. This approach enables the optimal assimilation of meteorological data from a variety of heights in the ABL and a sensitivity analysis provides the necessary weight functions. Application of the theory to one set of data over sea shows that a significant improvement in the fit to the data is achieved when the roughness length for heat is assumed to be much greater than the roughness length for wind.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 01, 1999
- Accession Number
- ADA368668
Entities
People
- C. P. Baker
- D. M. Phillips