ESA Consults
European Science Community on Candidate Earth Explorer Missions
(15 April 2004) On 19 and 20
April at ESA’s establishment in Frascati, near Rome, the ESA Directorate
of Earth Observation is holding an Earth Explorer User Consultation Meeting at
which the findings of the scientific and technical evaluations of the six
candidates for the next generation of Earth Explorer missions will be presented
and discussed by leading scientists from the European Earth science
community.
The six candidate missions for Earth
Explorer, part of ESA’s Living Planet programme, are:
EarthCARE -
Earth Clouds Aerosols and Radiation Explorer - to improve the representation
and understanding of the Earth’s radiative balance in climate and
numerical weather forecast models by acquiring vertical profiles of clouds and
aerosols, as well as the radiances at the top of the atmosphere. From a single
platform in a 450 km polar orbit a lidar (laser radar) will acquire data on
aerosols and thin clouds and a high frequency radar will do the same for thick
clouds. A multi-spectral imager will provide additional information on
distribution of aerosol and cloud optical properties, and a broadband
radiometer will measure radiances.
SPECTRA - Surface Processes and
Ecosystem Changes Through Response Analysis - to describe, understand and model
the role of terrestrial vegetation in the global carbon cycle and its response
to climate variability under the increasing pressure of human activity. The
mission will carry an imaging spectrometer to analyse radiance from vegetation.
From a near-polar 670 km altitude orbit SPECTRA will collect data over a
selection of regions representative of all the Earth’s major biomes.
WALES - Water VApour and Lidar Experiment in Space - to provide global
water vapour observations in the troposphere and lowermost stratosphere with
high vertical resolution and accuracy to support climate and numerical weather
prediction. WALES, a polar orbiting satellite at 450 km altitude, hosts a lidar
using four wavelengths with different water vapour absorptions adapted to the
large mixing ratio of water vapour in the atmosphere.
ACE+ -
Atmosphere and Climate Explorer - to establish highly accurate measurements of
humidity and temperature in the troposphere and the stratosphere for climate
trend observations. ACE+ comprises four satellites flying as two pairs in the
same Sun-synchronous orbital plane but at two different altitudes. The
satellites in the 650 km orbit will counter-rotate with respect to the
satellites in the 800 km orbit.
EGPM - European contribution to Global
Precipitation Measurement - to provide improved observations of light rain and
snowfall and to contribute to the monitoring and understanding of storms that
produce hazards such as flash floods. The overall Global Precipitation
Measurement mission consists of a core platform equipped with microwave
instruments and a number of smaller satellites to give a repeat observation
cycle of approximately three hours. One of these satellites will be EGPM flying
in a Sun-synchronous near-polar orbit at 510 km altitude with two instruments
on board, a microwave radiometer and a precipitation radar.
Swarm - a
constellation of three magnetometry satellites - to provide the best ever
survey of the geomagnetic field and its temporal evolution. Swarm will offer
new insights into the composition and processes in the interior and the
surroundings of the Earth, thereby improving our knowledge of climate. The
satellites will drift in near-polar orbital planes at 530 and 450 km altitude.
Each satellite will carry a magnetometry package, an electric field instrument
and an accelerometer.
(source: ESA)