The onset of turbulence in an elevated layer near sunrise

✍ Scribed by R. C. Wanta

• Book ID: 104571465
• Publisher: John Wiley and Sons
• Year: 1953
• Tongue: English
• Weight: 402 KB
• Volume: 79
• Category: Article
• ISSN: 0035-9009
• DOI: 10.1002/qj.49707934107

✦ Synopsis

Abstract

Abrupt changes at heights 46 m and 125 m above the ground from smooth flow, or flow in which damped eddies occur, to a flow characterized by continuing gustiness are investigated in terms of a critical Richardson number. Such transitions at Upton, N.Y. during the period October‐November 1950 are identified from continuous records of the wind direction. Account is taken of the time for the transition to propagate across the layer. Fourteen transitions during the period studied, all near sunrise, indicate that the (layer) critical number for eddies with periods somewhat less than one minute lies within the range from 1/3 to 1/2. It is suggested that the method used may be applicable to other eddy sizes.