Accession Number:

ADA247116

Title:

Potential Refractivity as a Similarity Variable

Descriptive Note:

Journal article

Corporate Author:

NAVAL OCEANOGRAPHIC AND ATMOSPHERIC RESEARCH LAB MONTEREY CA

Personal Author(s):

• Cook, John
• Burk, Stephen

Report Date:

1992-01-01

Pagination or Media Count:

10.0

Abstract:

The validity of a common radiometeorological application of Monin-Obukhov M-0 similarity theory to potential refractivity Chi, which is a nonlinear combination of theta and q, is determined by whether the properly nondimensionalized chi gradient is a universal function of ZL. We develop expressions for the flux of chi and its scaling parameter, chi in terms of temperature and moisture fluxes, and an M-O similarity expression for the vertical chi gradient. Results show that even is theta and q are accepted as exactly following M-O similarity expressions, when the surface layer is stable, chi does not obey such an expression. That is, when properly nondimensionalized, the vertical gradient of chi does not collapse to a single universal function of ZL. The assumption that chi behaves as a similarity variable is approximately correct for well-mixed surface layers under unstable and near-neutral conditions. The gradient of chi is an important factor in determining microwave propagation conditions. We demonstrate the error induced in a simple algorithm when chi is assumed to obey M-O similarity theory. An alternative methodology, consistent with the application of similarity theory to theta and q, is then developed without requiring that chi itself satisfy similarity theory.

Descriptors:

• *REFRACTION
• *BOUNDARY LAYER
• *OCEAN SURFACE
• *MICROWAVES
• METHODOLOGY
• TEMPERATURE
• CLOSURES
• LAYERS
• PARAMETERS
• THEORY
• METEOROLOGICAL RADAR
• VARIABLES
• SURFACES
• BOUNDARIES
• WAVE PROPAGATION
• ERRORS
• SCALING FACTOR
• MIXING
• MOISTURE
• AIR WATER INTERACTIONS
• HUMIDITY
• COLLAPSE
• REPRINTS
• PROPAGATION
• GRADIENTS
• ALGORITHMS
• FUNCTIONS

Subject Categories:

• Meteorology
• Physical and Dynamic Oceanography
• Radiofrequency Wave Propagation

Distribution Statement:

APPROVED FOR PUBLIC RELEASE