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| Titel |
Evaluation of sensible heat flux from remote sensing and eddy correlation data for two Portuguese cork-oak forests |
| VerfasserIn |
John Cunha, Teresa A. Paço, Filipe Costa e Silva, Jorge S. David, João S. Pereira, Iana Rufino, Carlos Galvão, Fernanda Valente |
| Konferenz |
EGU General Assembly 2015
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250106908
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| Publikation (Nr.) |
 EGU/EGU2015-6591.pdf |
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| Zusammenfassung |
| Energy balance is a major determinant of Earth surface temperature and climate. However,
the physics of energy balance computations are complex and vary in space and in time. Most
of the data available on the energy balance of non-agricultural systems is from local
measurements, only representative of the area around the measuring point. To overcome this,
remote sensing techniques have been widely used, particularly in studies on the temporal
land-cover changes and on their influences on the energy and water balances. Several
remote sensors with different spatial, temporal and spectral resolutions have been
used to understand these processes. In many applications, the main objective is to
understand how landscape’s changes over time can influence regional climate. Orbital
information enables the analysis of the spatial and temporal features of the Earth’s
surface, and to understand the interactions between different land-cover types with
topography, atmospheric and anthropogenic action. However, to test for accuracy and
precision, data from satellite sensors and their derivatives need to be compared
with ground-level field data. This study evaluates and tests sensible heat flux data
obtained from the SEBAL algorithm using images by Thematic Mapper (TM) sensor
aboard Landsat 5 satellite. These sensible heat flux data were compared with those of
two ground level experiments, with the Eddy Covariance technique, in Évora and
Coruche, Portugal. The footprints of the sensible heat flux measurements were
calculated for six scenes of sensor TM, allowing the comparison between satellite data
and surface flux data. Results showed a high correlation between sensible heat
flux data derived from remote sense and ground-level measurements (R2=0.94).
We conclude that the remote sensing technique is useful in estimating this energy
balance component and may contribute to the understanding of vegetation dynamics. |
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