Role of land-surface temperature feedback on model performance for the stable boundary layer |
| |
| Authors: | A A M Holtslag G J Steeneveld B J H van de Wiel |
| |
| Institution: | (1) Meteorology and Air Quality Section, Wageningen University, Wageningen, The Netherlands |
| |
| Abstract: | At present a variety of boundary-layer schemes is in use in numerical models and often a large variation of model results
is found. This is clear from model intercomparisons, such as organized within the GEWEX Atmospheric Boundary Layer Study (GABLS).
In this paper we analyze how the specification of the land-surface temperature affects the results of a boundary-layer scheme,
in particular for stable conditions. As such we use a well established column model of the boundary layer and we vary relevant
parameters in the turbulence scheme for stable conditions. By doing so, we can reproduce the outcome for a variety of boundary-layer
models. This is illustrated with the original set-up of the second GABLS intercomparison study using prescribed geostrophic
winds and land-surface temperatures as inspired by (but not identical to) observations of CASES-99 for a period of more than
two diurnal cycles. The model runs are repeated using a surface temperature that is calculated with a simple land-surface
scheme. In the latter case, it is found that the range of model results in stable conditions is reduced for the sensible heat
fluxes, and the profiles of potential temperature and wind speed. However, in the latter case the modelled surface temperatures
are rather different than with the original set-up, which also impacts on near-surface air temperature and wind speed. As
such it appears that the model results in stable conditions are strongly influenced by non-linear feedbacks in which the magnitude
of the geostrophic wind speed and the related land-surface temperature play an important role. |
| |
| Keywords: | Atmosphere-land interaction Boundary-layer parameter study GABLS Model evaluation Model intercomparison study Land-surface temperature feedback Stable boundary layer |
| 本文献已被 SpringerLink 等数据库收录！ |
|
