Aerodynamic roughness as a function of wind direction over asymmetric surface elements

✍ Scribed by B. S. Jackson; J. J. Carroll

• Publisher: Springer
• Year: 1978
• Tongue: English
• Weight: 487 KB
• Volume: 14
• Category: Article
• ISSN: 0006-8314
• DOI: 10.1007/bf00121042

✦ Synopsis

Wind speed and temperature profiles to a height of 8 m were recorded for 30-, 60-, and 90-min averaging times over a striated snow surface at the geographic South Pole during the austral winter of 1975. A gradient Richardson number was calculated for each averaging time to determine conditions of neutral stability under which the logarithmic wind law would hold. A log-linear regression technique was used to determine values of aerodynamic roughness height (2,) for those profile averages recorded in conditions of neutral stability. A plot of 2, as a function of average wind direction revealed a variation in Z,, of almost three orders of magnitude, from 0.01 to 7 cm, over 120 deg of wind direction. A simple model is presented to justify the fact that aerodynamic roughness is a function of wind direction and erosion history.