Improvement of surface flux parametrizations with a turbulence‐related length

In surface flux parametrizations, aerodynamic roughness length zm0, and thermal roughness length zh0, are used to account for different resistances for momentum transfer and heat transfer. This paper introduces a turbulence-related length hT and parametrizes the quantity kA−1=ln(hT/zh0) in order to estimate zh0. Based on data at three sites on the Tibetan Plateau, a general formula for kA−1 is obtained for the surfaces covered by bare soil or partially covered by very short vegetation. A surface flux parametrization with this formula provides better estimates of heat flux than either profile flux parametrization or surface flux parametrization with kB−1 (i.e. ln(zm0/zh0)). Therefore, the use of a reasonable length to scale zh0 can contribute to the improvement of surface flux parametrizations. Copyright © 2002 Royal Meteorological Society

[1]  J. Garratt.  The Atmospheric Boundary Layer , 1992 .

[2]  R. Francey,et al.  Bulk characteristics of heat transfer in the unstable, baroclinic atmospheric boundary layer , 1978 .

[3]  J. Norman,et al.  Evaluation of soil and vegetation heat flux predictions using a simple two-source model with radiometric temperatures for partial canopy cover , 1999 .

[4]  M. S. Moran,et al.  Determination of sensible heat flux over sparse canopy using thermal infrared data , 1989 .

[5]  Yann Kerr,et al.  Estimation of sensible heat flux over sparsely vegetated surfaces , 1997 .

[6]  Kenji Tanaka,et al.  Surface Energy Budget at Amdo on the Tibetan Plateau using GAME/Tibet IOP98 Data. , 2001 .

[7]  Toshio Koike,et al.  Analytical Solution of Surface Layer Similarity Equations , 2001 .

[8]  Daewon W. Byun,et al.  On the Analytical Solutions of Flux-Profile Relationships for the Atmospheric Surface Layer , 1990 .

[9]  B. Hurk,et al.  Estimation of the sensible heat flux of a semi-arid area using surface radiative temperature measurements , 1993 .

[10]  On the role of roughness lengths in flux parameterizations of boundary-layer models , 1996 .

[11]  A. Kubota,et al.  Radiometrically determined skin temperature and scalar roughness to estimate surface heat flux part II: Performance of parameterized scalar roughness for the determination of sensible heat , 1994 .

[12]  J. Launiainen.  Derivation of the relationship between the Obukhov stability parameter and the bulk Richardson number for flux-profile studies , 1995 .

[13]  W. Brutsaert.  Evaporation into the atmosphere , 1982 .

[14]  W. J. Massman,et al.  A model study of kBH−1 for vegetated surfaces using ‘localized near-field’ Lagrangian theory , 1999 .

[15]  W. Brutsaert,et al.  Sensible Heat Transfer Parameterization for Surfaces with Anisothermal Dense Vegetation , 1996 .

[16]  A. S. Thom,et al.  Momentum, mass and heat exchange of vegetation , 1972 .

[17]  J. Louis.  A parametric model of vertical eddy fluxes in the atmosphere , 1979 .

[18]  T. Koike,et al.  GAME-Tibet IOP Summary Report. , 1999 .

[19]  U. Högström.  Review of some basic characteristics of the atmospheric surface layer , 1996 .

[20]  G. Bezine,et al.  Viscous Fluid Mechanics , 1989 .

[21]  Steven R. Hanna,et al.  Hybrid Plume Dispersion Model (HPDM) Development and Evaluation , 1989 .

[22]  I. Tamagawa.  Considerations on the Eddy Correlation Method Using Sonic Anemometer-Thirmometer and Infrared Hygrometer , 1999 .

[23]  J. Monteith,et al.  Radiative surface temperature and energy balance of a wheat canopy , 1986 .

[24]  A Simple Formula for Estimation of the Roughness Length for Heat Transfer over Partly Vegetated Surfaces , 1999 .

[25]  S. Emori,et al.  A simple extension of the Louis method for rough surface layer modelling , 1995 .

[26]  Larry Mahrt,et al.  The bulk aerodynamic formulation over heterogeneous surfaces , 1996 .

[27]  Jean-Paul Lhomme,et al.  Sensible Heat Flux-Radiometric Surface Temperature Relationship Over Sparse Vegetation: Parameterizing B-1 , 2000, Boundary-Layer Meteorology.

[28]  Anne Verhoef,et al.  Some Practical Notes on the Parameter kB−1 for Sparse Vegetation , 1997 .

[29]  Jielun Sun,et al.  Diurnal Variations of Thermal Roughness Height over a Grassland , 1999 .

[30]  H. Lee.  Improvement of Surface Flux Calculations in the Atmospheric Surface Layer , 1997 .

[31]  B. Hicks,et al.  Momentum, heat and water vapour transfer to and from natural and artificial surfaces , 1973 .

[32]  Hervé Giordani,et al.  A modified parameterization of flux-profile relationships in the surface layer using different roughness length values for heat and momentum , 1995 .

[33]  A. Holtslag,et al.  On the bulk parameterization of surface fluxes for various conditions and parameter ranges , 1997 .

[34]  William P. Kustas,et al.  An Evaluation of Two Models for Estimation of the Roughness Height for Heat Transfer between the Land Surface and the Atmosphere , 2001 .

[35]  M. S. Moran,et al.  Sensible heat flux - Radiometric surface temperature relationship for eight semiarid areas , 1994 .

[36]  Y. Malhi.  The behaviour of the roughness length for temperature over heterogeneous surfaces , 1996 .