Monin-Obukhov Similarity for Refractive Index Revisited

Abstract

Monin-Obukhov similarity applied to the real part of the refractive index variance n?2 is discussed. It is shown that, because the observed correlation coefficient rTQ between temperature and humidity is less than unity, scaling by n* = n?w?/u* (where u* is the friction velocity) makes the dimensionless variance n?2/n?*2 dependent on two dimensionless parameters, on dimensionless height z/L (where L is the Monin-Obukhov length), and on a parameter R, which is related to the Bowen ratio. As the Monin-Obukhov similarity framework is applied, a large scatter of the dimensionless refractive index variance is expected for certain values of the Bowen ratio. Such a scatter can be eliminated if a new scale N*, defined as a combination of temperature and humidity scales, is employed.