Nocturnal boundary layer height prediction from surface routine meteorological data

A number of well known diagnostic equations for the determination of the he ight, h, of the nocturnal boundary layer, with minimum data requirements of at most surface wind speed, air temperature and total cloud cover, have be en tested as to their effectiveness. The computed values have been compared with direct estimation of h, from temperature or wind profiles of rawinson de ascents available at 00Z (02h LST). The comparison between computed and observed values shows that best agreement is found when the nocturnal bound ary layer height is determined through wind profiles. The ratio of the comp uted to the observed values reveals a strong dependence on stability, resul ting in overestimation by the models for very low stability and underestima tion for strong stability. The simple expressions involving the wind speed rather than other stability parameters resulted in a better overall fit to the observed values. A simple prognostic model is shown to provide the best estimates of the NBL height compared to both wind and temperature profile definition.