Chapter 9
THE CONTRIBUTION OF REMOTE SENSING
TECHNOLOGIES AND ALGORITHMS TO LAND
SURFACE PROCESSES STUDIES
B. Pinty and M. M. Verstraete
Space Applications Institute, Ispra, Italy.
1.
INTRODUCTION
Solar radiation is the primary source of energy driving the atmosphere,
the hydrosphere and the biosphere. The models needed to estimate or predict
the amount of radiative energy available as a function of space and time
must therefore be based on a thorough understanding of the processes
controlling the absorption and scattering of light in these geophysical
environments. The bulk of the solar energy available to drive the global
Earth system is in fact absorbed at the lower boundary of the atmosphere
(oceans and terrestrial surfaces). Surface-atmosphere interactions play an
important role at a variety of spatial and temporal scales, including those
relevant to the phenomena that control the possible occurrence of convective
precipitation. This is especially the case in the context of Soil-VegetationAtmosphere Transfer (SVAT) models that simulate the environment with a
time step of a few minutes to an hour. These processes have been
extensively studied at the local scale (e.g., Geiger 1965, Oke 1978, Monteith
and Unsworth 1990).
At a minimum, atmospheric General Circulation Models (GCM) require
a specification of the mass, energy and momentum fluxes at their lower
boundary. These boundary conditions may take the form of expressions
similar to that for the well-known radiation balance at the Earth’s surface.
Stand-alone SVAT schemes and advanced land surface processes codes,
71
M.M. Verstraete et al. (eds.), Observing Land from Space: Science, Customers and Technology, 71–76.
© 2000 Kluwer Academic Publishers. Printed in the Netherlands.
THE CONTRIBUTION OF REMOTE SENSING
TECHNOLOGIES AND ALGORITHMS TO LAND
SURFACE PROCESSES STUDIES
B. Pinty and M. M. Verstraete
Space Applications Institute, Ispra, Italy.
1.
INTRODUCTION
Solar radiation is the primary source of energy driving the atmosphere,
the hydrosphere and the biosphere. The models needed to estimate or predict
the amount of radiative energy available as a function of space and time
must therefore be based on a thorough understanding of the processes
controlling the absorption and scattering of light in these geophysical
environments. The bulk of the solar energy available to drive the global
Earth system is in fact absorbed at the lower boundary of the atmosphere
(oceans and terrestrial surfaces). Surface-atmosphere interactions play an
important role at a variety of spatial and temporal scales, including those
relevant to the phenomena that control the possible occurrence of convective
precipitation. This is especially the case in the context of Soil-VegetationAtmosphere Transfer (SVAT) models that simulate the environment with a
time step of a few minutes to an hour. These processes have been
extensively studied at the local scale (e.g., Geiger 1965, Oke 1978, Monteith
and Unsworth 1990).
At a minimum, atmospheric General Circulation Models (GCM) require
a specification of the mass, energy and momentum fluxes at their lower
boundary. These boundary conditions may take the form of expressions
similar to that for the well-known radiation balance at the Earth’s surface.
Stand-alone SVAT schemes and advanced land surface processes codes,
71
M.M. Verstraete et al. (eds.), Observing Land from Space: Science, Customers and Technology, 71–76.
© 2000 Kluwer Academic Publishers. Printed in the Netherlands.