The Risø profiles: A study of wind and temperature data from the 123-m tower at Risø, Denmark

✍ Scribed by Ernest W. Peterson

• Publisher: John Wiley and Sons
• Year: 1975
• Tongue: English
• Weight: 526 KB
• Volume: 101
• Category: Article
• ISSN: 0035-9009
• DOI: 10.1002/qj.49710142709

✦ Synopsis

Abstract

A new study has been made of the Risø profiles with the following conclusions:
roughness lengths determined from neutral wind profiles selected by gradient Richardson number are biased towards high roughness lengths. Selecting the profiles by using a bulk Richardson number criterion yields average profiles with lower roughness lengths. This roughness length is relatively independent of stability while that determined from profiles using a gradient Richardson number is greater than the roughness lengths for either stable or unstable cases;

it is doubtful whether ‘double kinks’ in some of the Risø wind profiles are caused by local terrain inhomogeneities, as has previously been suggested;

three‐dimensionality and unknown mesoscale and baroclinic effects make it difficult if not impossible to compare current change‐of‐terrain theory with the Riø 123‐m tower data.