Natural convection in the earth's boundary layer

✍ Scribed by A. A. Townsend

• Publisher: John Wiley and Sons
• Year: 1962
• Tongue: English
• Weight: 349 KB
• Volume: 88
• Category: Article
• ISSN: 0035-9009
• DOI: 10.1002/qj.49708837505

✦ Synopsis

Abstract

The relation between the vertical distributions of mean temperature in buoyant convection over a horizontal surface as observed in the atmosphere and in the laboratory is examined. Some measurements by Webb, obtained in conditions of strong instability, are analysed and shown to be consistent with three distinct regions of flow, distinguished by their heat‐transfer characteristics. They are:

a region of forced convection with temperature gradient inversely proportional to height (negative Richardson number less than 0·02);

a region of mixed (or free) convection with temperature gradient inversely proportional to the 4/3‐power of the height (negative Richardson number between 0·03 and 1·0) and

a region of natural convection with temperature gradient inversely proportional to the square of the height (negative Richardson number greater than 1·0).

Reasons for the existence and properties of the last two regions are discussed briefly.