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| Titel |
Modelling the responses of atmosphere-biosphere interactions to changing land use and climate in the Amazon basin-a project overview. |
| VerfasserIn |
László H. Hajdu, Andrew D. Friend, Michael Herzog, A. Johannes Dolman |
| Konferenz |
EGU General Assembly 2013
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 15 (2013) |
| Datensatznummer |
250080585
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| Zusammenfassung |
| Several modelling experiments of different spatial and time resolution are conducted to
address the uncertainties of local and regional changes in the hydrological and carbon cycles
due to land use change in the Amazon river basin. The models used are the numerical
process-based terrestrial ecosystem dynamics model HYBRID 8, the high resolution
atmospheric model ATHAM (Active Tracer High-resolution Atmosphere Model) and a
simple idealized coupled soil-atmosphere 0-d model.
High resolution experiments with spatial resolution of the order of a couple of hundreds
of meters and temporal resolution of 2-3 seconds will be conducted with ATHAM-HYBRID,
to study the effects of different vegetation cover on cloud formation and on mesoscale
convective events.
The possible feedback mechanism of short lived clouds on vegetation will also be
analysed.
These experiments are necessary to demonstrate the importance of cumulus clouds in
the atmospheric boundary layer both on the hydrologic and carbon diurnal cycles.
The boundary layer clouds modify the near-surface climate and they also affect
the diurnal CO2 cycle, diffusing the solar radiation, which enhances the uptake of
CO2 by vegetation, leading to changes in the carbon fixation ratio (Arellano et al.
2012).
For the effect of land use change at a regional level and on longer timescales, the 0-d
model will be used to generate rainfall. We will use several scenarios with decreasing
advection from Atlantic Ocean and decreasing local recycling for investigating the resilience
and stability of vegetation to climate and land use change.
The resulting precipitation and temperature then will be used as input to force the
dynamic vegetation model HYBRID until equilibrium is achieved in the carbon pools. The
changes in the hydrological cycle, gross primary production, net ecosystem exchange and
total ecosystem respiration will be investigated.
We will compare the output from both experiment types (ATHAM/HYBRID, 0-d
model/HYBRID to the flux data from different humid tropical experiments namely LBA and
FLUXNET. |
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