Comments on ' Determining height of the nocturnal boundary layer'.

Abstract

Yu (1978) compares three theoretical diagnostic parameterizations of the nocturnal boundary layer depth with Wangara data. The actual boundary layer depth is estimated in three different ways based on observed profiles of temperatures, wind and cooling rate. Yu is unable to test conclusively the three diagnostic methods because they are so highly correlated with each other and because there is considerable ambiguity in determination of the actual boundary layer depth. However, since routine profiles of turbulence quantities in the nocturnal boundary layer do not exist at a reasonably homogeneous site, Yu's approach is the only possibility. The diagnostic estimates are greatly oversimplified and/or actual depths of the nocturnal boundary layer cannot be determined from profiles of momentum and temperature. Routine measurements of actual profiles of turbulence at different latitudes would be required to resolve this issue. -from Author