Chapter 1
Energy and Water Cycles in the
Climate System: What can we
measure from space?
Ehrhard Raschke
GKSS-Forschungszentrum
D-21502 Geesthacht
Germany
Abstract
This first paper of a lecture series on various specific problems, which are related to spaceborne
and ground-based remote sensing of several components of our climate system describing energy
and water cycles over the entire globe and specific regions of it, intends to provide a first
brief overview on our present knowledge of them. It further will introduce into the principles,
limitations and problems of their direct and remote measurements from space, within the
atmosphere and from ground where the latter ones are often the first step towards a space
experiment. More recent details on our present knowledge on them and their observations can
be found in the many individual papers, following thereafter.
We concentrate here, following the major research strategy of the Global Energy and Water
Cycles Experiment (GEWEX, see WCRP 1990), on the major components of the water budget,
on the radiation budget and on water transports in the atmosphere and at ground. This brief
review cannot be complete nor exhausting. It purposely quotes some work which has been
performed some 20 years ago and earlier.
1.1 Introduction
Our climate system, consisting of the atmosphere, oceans with varying sea-ice cover, landsurfaces with their complex vegetative cover and orography and of the cryosphere (ice sheets
over Greenland and Antarctica, continental glaciers), is steadily in motion within a wide spectrum of spatial and temporal scales which are ranging from millimeters to 10.000 km and
from milliseconds to several or hundreds of years, respectively. These dynamical processes
and their complex interactions and the resulting exchanges of energy, momentum and material
must completely be understood and then also be reconstructed to a certain degree of detail
NATO ASI Series. Vol. 145
Radiation and Water in the Climate System:
Remote Measurements
Edited by Ehrhard Raschke
e> Springer-Verlag Berlin Heidelberg 1996
Energy and Water Cycles in the
Climate System: What can we
measure from space?
Ehrhard Raschke
GKSS-Forschungszentrum
D-21502 Geesthacht
Germany
Abstract
This first paper of a lecture series on various specific problems, which are related to spaceborne
and ground-based remote sensing of several components of our climate system describing energy
and water cycles over the entire globe and specific regions of it, intends to provide a first
brief overview on our present knowledge of them. It further will introduce into the principles,
limitations and problems of their direct and remote measurements from space, within the
atmosphere and from ground where the latter ones are often the first step towards a space
experiment. More recent details on our present knowledge on them and their observations can
be found in the many individual papers, following thereafter.
We concentrate here, following the major research strategy of the Global Energy and Water
Cycles Experiment (GEWEX, see WCRP 1990), on the major components of the water budget,
on the radiation budget and on water transports in the atmosphere and at ground. This brief
review cannot be complete nor exhausting. It purposely quotes some work which has been
performed some 20 years ago and earlier.
1.1 Introduction
Our climate system, consisting of the atmosphere, oceans with varying sea-ice cover, landsurfaces with their complex vegetative cover and orography and of the cryosphere (ice sheets
over Greenland and Antarctica, continental glaciers), is steadily in motion within a wide spectrum of spatial and temporal scales which are ranging from millimeters to 10.000 km and
from milliseconds to several or hundreds of years, respectively. These dynamical processes
and their complex interactions and the resulting exchanges of energy, momentum and material
must completely be understood and then also be reconstructed to a certain degree of detail
NATO ASI Series. Vol. 145
Radiation and Water in the Climate System:
Remote Measurements
Edited by Ehrhard Raschke
e> Springer-Verlag Berlin Heidelberg 1996