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contributor authorBertoldi, Giacomo
contributor authorKustas, William P.
contributor authorAlbertson, John D.
date accessioned2017-06-09T16:18:26Z
date available2017-06-09T16:18:26Z
date copyright2008/08/01
date issued2008
identifier issn1558-8424
identifier otherams-65428.pdf
identifier urihttp://onlinelibrary.yabesh.ir/handle/yetl/4206652
description abstractThis paper investigates the spatial relationships between surface fluxes and near-surface atmospheric properties (AP), and the potential errors in flux estimation due to homogeneous atmospheric inputs over heterogeneous landscapes. A large-eddy simulation (LES) model is coupled to a surface energy balance scheme with remotely sensed surface temperature Ts as a key boundary condition. Simulations were performed for different agricultural regions having major contrasts in Ts, canopy cover, and surface roughness z0 between vegetated/irrigated and bare soil areas. If AP from a single weather station in a nonrepresentative location within the landscape are applied uniformly over the domain, significant differences in surface flux estimation with respect to the LES output are observed. The spatial correlations of AP with the fluxes, the land cover properties, and surface states were examined and the spatial scaling of these fields is analyzed using a two-dimensional wavelet technique. The results indicate a significant local correlation of the spatial distributions of the air temperature Ta with the sensible heat flux H, the specific humidity q with the latent heat flux LE, and the wind speed U with z0. These relationships can be described by a general linear form, suggesting that a simple regression relation may be applicable for most agricultural landscapes to estimate spatially variable AP fields. A simple yet practical method is proposed using remotely sensed observations and the land surface scheme, based on general linear expressions derived between Ta and H, q and LE, and U and z0. The method is shown to reproduce the main spatial patterns of AP and to reduce potential errors in local and regionally averaged heat flux estimation. This approach is recommended when only local weather station observations are available.
publisherAmerican Meteorological Society
titleEstimating Spatial Variability in Atmospheric Properties over Remotely Sensed Land Surface Conditions
typeJournal Paper
journal volume47
journal issue8
journal titleJournal of Applied Meteorology and Climatology
identifier doi10.1175/2007JAMC1828.1
journal fristpage2147
journal lastpage2165
treeJournal of Applied Meteorology and Climatology:;2008:;volume( 047 ):;issue: 008
contenttypeFulltext


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