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Surface fluxes in heterogeneous landscape

Abstract

The surface fluxes in homogeneous landscapes are calculated by similarity scaling principles. The methodology is well establish. In heterogeneous landscapes with spatial changes in the micro scale range, i e from 100 m to 10 km, advective effects are significant. The present work focus on these effects in an agricultural countryside typical for the midlatitudes. Meteorological and satellite data from a highly heterogeneous landscape in the Rhine Valley, Germany was collected in the large-scale field experiment TRACT (Transport of pollutants over complex terrain) in 1992. Classified satellite images, Landsat TM and ERS SAR, are used as basis for roughness maps. The roughnesses were measured at meteorological masts in the various cover classes and assigned pixel by pixel to the images. The roughness maps are aggregated, i e spatially averaged, into so-called effective roughness lengths. This calculation is performed by a micro scale aggregation model. The model solves the linearized atmospheric flow equations by a numerical (Fast Fourier Transform) method. This model also calculate maps of friction velocity and momentum flux pixel wise in heterogeneous landscapes. It is indicated how the aggregation methodology can be used to calculate the heat fluxes based on the relevant satellite data i e temperature and  More>>
Authors:
Publication Date:
Jan 01, 1997
Product Type:
Thesis/Dissertation
Report Number:
RISO-R-922(EN)
Reference Number:
SCA: 540110; 540120; PA: DK-97:001147; EDB-97:043655; NTS-97:008131; SN: 97001752159
Resource Relation:
Other Information: TH: Thesis (ph.d.); PBD: Jan 1997
Subject:
54 ENVIRONMENTAL SCIENCES; ROUGHNESS; REMOTE SENSING; AIR-BIOSPHERE INTERACTIONS; BOUNDARY LAYERS; ENVIRONMENTAL TRANSPORT; FLOW MODELS; TWO-DIMENSIONAL CALCULATIONS; MAPPING; BOUNDARY CONDITIONS; LANDSAT SATELLITES; RADAR; FOURIER TRANSFORMATION
OSTI ID:
446248
Research Organizations:
Risoe National Lab., Roskilde (Denmark). Meteorology and Wind Energy; Copenhagen Univ. (Denmark)
Country of Origin:
Denmark
Language:
English
Other Identifying Numbers:
Other: ON: DE97732882; ISBN 87-550-2218-9; TRN: DK9701147
Availability:
Also available from Risoe Library, P.O. Box 49, DK-4000 Roskilde, Denmark; OSTI as DE97732882
Submitting Site:
DK
Size:
180 p.
Announcement Date:

Citation Formats

Bay Hasager, C. Surface fluxes in heterogeneous landscape. Denmark: N. p., 1997. Web.
Bay Hasager, C. Surface fluxes in heterogeneous landscape. Denmark.
Bay Hasager, C. 1997. "Surface fluxes in heterogeneous landscape." Denmark.
@misc{etde_446248,
title = {Surface fluxes in heterogeneous landscape}
author = {Bay Hasager, C}
abstractNote = {The surface fluxes in homogeneous landscapes are calculated by similarity scaling principles. The methodology is well establish. In heterogeneous landscapes with spatial changes in the micro scale range, i e from 100 m to 10 km, advective effects are significant. The present work focus on these effects in an agricultural countryside typical for the midlatitudes. Meteorological and satellite data from a highly heterogeneous landscape in the Rhine Valley, Germany was collected in the large-scale field experiment TRACT (Transport of pollutants over complex terrain) in 1992. Classified satellite images, Landsat TM and ERS SAR, are used as basis for roughness maps. The roughnesses were measured at meteorological masts in the various cover classes and assigned pixel by pixel to the images. The roughness maps are aggregated, i e spatially averaged, into so-called effective roughness lengths. This calculation is performed by a micro scale aggregation model. The model solves the linearized atmospheric flow equations by a numerical (Fast Fourier Transform) method. This model also calculate maps of friction velocity and momentum flux pixel wise in heterogeneous landscapes. It is indicated how the aggregation methodology can be used to calculate the heat fluxes based on the relevant satellite data i e temperature and soil moisture information. (au) 10 tabs., 49 ills., 223 refs.}
place = {Denmark}
year = {1997}
month = {Jan}
}