All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 453 162 24
PDF Downloads 325 119 10

A Simple Parameterization of the Surface Fluxes of Sensible and Latent Heat During Daytime Compared with the Penman-Monteith Concept

H. A. R. De BruinRoyal Netherlands Meteorological Institute, De Bilt, The Netherlands

Search for other papers by H. A. R. De Bruin in
Current site
Google Scholar
PubMed
Close
and
A. A. M. HoltslagRoyal Netherlands Meteorological Institute, De Bilt, The Netherlands

Search for other papers by A. A. M. Holtslag in
Current site
Google Scholar
PubMed
Close
Full access

Abstract

A comparison is made between two methods for determining the surface fluxes of sensible and latent heat during daytime. The first method, known as the Penman-Monteith approach, incorporates a more complete description of the physics. However, it needs a relatively large number of input parameters, which is inconvenient in many applications. The second method is a modification of the Priestley-Taylor evaporation model, which needs only net radiation, air temperature and an indication of the moisture condition at the surface. Both models are compared on the basis of hourly micro-meteorological data above short grass obtained in the Netherlands during the summer of 1977. The experiments were performed under predominantly unstable conditions [0 ≥ z/L0 ≥ −0.3z = (mean) measuring height, L0 = Obukhov length] with weak or no advection. It appears that, under these environmental conditions, the models have a similar skill. Therefore, the simple parameterization is preferred for practical purposes. It reveals that this result can be partially explained by the fact that the so-called equilibrium latent heat flux density LEEQ and vapor pressure deficit are correlated. The method requires further verification for different climatological conditions.

Abstract

A comparison is made between two methods for determining the surface fluxes of sensible and latent heat during daytime. The first method, known as the Penman-Monteith approach, incorporates a more complete description of the physics. However, it needs a relatively large number of input parameters, which is inconvenient in many applications. The second method is a modification of the Priestley-Taylor evaporation model, which needs only net radiation, air temperature and an indication of the moisture condition at the surface. Both models are compared on the basis of hourly micro-meteorological data above short grass obtained in the Netherlands during the summer of 1977. The experiments were performed under predominantly unstable conditions [0 ≥ z/L0 ≥ −0.3z = (mean) measuring height, L0 = Obukhov length] with weak or no advection. It appears that, under these environmental conditions, the models have a similar skill. Therefore, the simple parameterization is preferred for practical purposes. It reveals that this result can be partially explained by the fact that the so-called equilibrium latent heat flux density LEEQ and vapor pressure deficit are correlated. The method requires further verification for different climatological conditions.

Save