300
Chapter 29
4.2
Modeling the biosphere
To acquire knowledge on ecosystems, numerous models are being
refined, new ones being based on the basic eco-physiological processes.
While they do not generally need satellite data to be run, improvements can
be obtained from the comparison of their outputs with satellite
measurements of surface parameters. For example Kergoat (1998) and
Dedieu (1998) adapted rooting depth of forest biomes and introduced a
carbon budget constraint to limit leaves production so that the outputs of the
model became coherent with satellite measurements (Fig 7). To get
comparable measurements, important changes similar to some values
suggested in the literature had to be introduced: the continuous and accurate
measurements provided by VEGETATION will allow validation of these
changes on a global scale and will then provide better hypothesis for
interactions between the biosphere and atmosphere for global climate change
studies.
Chapter 29
4.2
Modeling the biosphere
To acquire knowledge on ecosystems, numerous models are being
refined, new ones being based on the basic eco-physiological processes.
While they do not generally need satellite data to be run, improvements can
be obtained from the comparison of their outputs with satellite
measurements of surface parameters. For example Kergoat (1998) and
Dedieu (1998) adapted rooting depth of forest biomes and introduced a
carbon budget constraint to limit leaves production so that the outputs of the
model became coherent with satellite measurements (Fig 7). To get
comparable measurements, important changes similar to some values
suggested in the literature had to be introduced: the continuous and accurate
measurements provided by VEGETATION will allow validation of these
changes on a global scale and will then provide better hypothesis for
interactions between the biosphere and atmosphere for global climate change
studies.