Andrew Yee[_1_]
May 16th 07, 05:10 PM
ESA News
http://www.esa.int
19 April 2007
Scientists and polar explorers brave the elements in support of CryoSat-2
It is perhaps an unlikely combination -- an international team of scientists
stationed in Svalbard, Norway and two polar explorers crossing the North
Pole on foot. Both teams, however, are currently part of a common effort to
collect vital data on the ground and from the air in support of ESA's ice
mission CryoSat-2.
The CryoSat-2 mission, due for launch in 2009, will provide highly accurate
information on changing marine and land ice thicknesses over the entire
north and south polar regions, and in doing so will help address key
questions regarding the impact of climate change on the polar environment.
The mission is a technical tour-de-force if you take a step back and
consider that the satellite will be travelling at over 25,000 kilometres per
hour at 717 kilometres above the surface of the Earth and yet still measure
changes in the ice thickness down to a few centimetres per year using its
sophisticated radar altimeter SIRAL. Given these objectives and the
importance of accurate measurements in assessing environmental change, it is
not surprising that ESA goes to great lengths to ensure that the data from
CryoSat-2 will be as accurate as possible.
Enter the Arctic Arc Expedition, part of the International Polar Year. The
expedition's two Belgian explorers, Alain Hubert and Dixie Dansercoer,
'stepped' onto the sea ice off the coast of Siberia on the 1 March 2007 and
have so far covered a staggering 2,500 km each pulling a 130-kg sledge
holding supplies and equipment. Along the way these two intrepid explorers
are contributing to the preparation of the CryoSat-2 mission by measuring
snow depths at regular intervals. These data in turn will be used by
scientists to assess how well snow conditions can be predicted using
existing climate models as well as inputs to methods for improving the
accuracy of CryoSat-2 maps of sea-ice thickness.
"We are making good progress," said Alain Hubert when contacted in his tent
on the ice with his satellite phone a few days ago. "We are now only 160 km
from the North Pole and taking snow-thickness measurements at regular
intervals along the way. Sometimes conditions are very difficult because of
the cold and wind. However, we feel the effort is worthwhile and we will
keep going."
As Alain and Dixie trek across the North Pole, a parallel campaign by
scientists from Germany, Norway and the UK is unfolding in the extreme
northern archipelago of Svalbard, Norway. On Thursday 12 April, a group of
eight scientists were transported by helicopter to the remote Austfonna ice
cap. As part of the CryoVex 2007 campaign, they will spend one month making
measurements of snow and ice properties along long transects that
criss-cross the ice sheet surface. Conditions on the ground are often
difficult, with high winds and low temperatures. The result is that
sometimes the instruments and equipment fail as the leader of the ground
team, Jon Ove Hagen from the University of Oslo, pointed out.
"We are currently moving our team from the depot at the bottom of the
Austfonna ice cap to the summit so that we can start our ground measurements
and support the airborne acquisition," said Jon Ove Hagen when contacted on
Monday 16 April. "Bad weather and a broken skidoo are simply things we need
to work around as we start our measurement programme."
As the ground experiments are carried out, measurements are also being taken
from the air by the Alfred Wegner Institute (AWI). The Dornier-228 aircraft
carries the ASIRAS instrument, which is an airborne version of the radar
altimeter instrument onboard CryoSat-2. By comparing the airborne data with
ground measurements scientists will test and verify novel methods for
retrieving ice-thickness change from the CryoSat-2 satellite mission ahead
of the launch.
"The first flight with ASIRAS looks good," says Veit Helm from AWI. "As soon
as the weather conditions are good and the ground teams are in place, we
look forward to our scientific flights and getting our hands dirty
processing and analysing the airborne radar altimeter data over Austfonna.
One fascinating aspect of such work is that the campaign actually allows us
to look into the future and see what the CryoSat-2 mission will see and
measure when it is launched."
The airborne work will continue until 24 April and the ground teams will
stay on the ice cap until the beginning of May. When the campaign draws to
an end, the challenge will then be to analyse the large volumes of data in
order to characterise and improve the CryoSat-2 measurements of changing ice
surfaces. In is only through such painstaking work that the challenge of
measuring ice thickness down to centimetre level from space can be achieved,
and in turn lead to a better understanding of the impact that changing
climate is having on the polar ice fields.
For more information please contact:
Malcolm Davidson
ESA CryoSat-2 Validation Manager
Malcolm.Davidson @ esa.int
[NOTE: Images and weblinks supporting this release are available at
http://www.esa.int/esaCP/SEMHIYLJC0F_index_1.html ]
http://www.esa.int
19 April 2007
Scientists and polar explorers brave the elements in support of CryoSat-2
It is perhaps an unlikely combination -- an international team of scientists
stationed in Svalbard, Norway and two polar explorers crossing the North
Pole on foot. Both teams, however, are currently part of a common effort to
collect vital data on the ground and from the air in support of ESA's ice
mission CryoSat-2.
The CryoSat-2 mission, due for launch in 2009, will provide highly accurate
information on changing marine and land ice thicknesses over the entire
north and south polar regions, and in doing so will help address key
questions regarding the impact of climate change on the polar environment.
The mission is a technical tour-de-force if you take a step back and
consider that the satellite will be travelling at over 25,000 kilometres per
hour at 717 kilometres above the surface of the Earth and yet still measure
changes in the ice thickness down to a few centimetres per year using its
sophisticated radar altimeter SIRAL. Given these objectives and the
importance of accurate measurements in assessing environmental change, it is
not surprising that ESA goes to great lengths to ensure that the data from
CryoSat-2 will be as accurate as possible.
Enter the Arctic Arc Expedition, part of the International Polar Year. The
expedition's two Belgian explorers, Alain Hubert and Dixie Dansercoer,
'stepped' onto the sea ice off the coast of Siberia on the 1 March 2007 and
have so far covered a staggering 2,500 km each pulling a 130-kg sledge
holding supplies and equipment. Along the way these two intrepid explorers
are contributing to the preparation of the CryoSat-2 mission by measuring
snow depths at regular intervals. These data in turn will be used by
scientists to assess how well snow conditions can be predicted using
existing climate models as well as inputs to methods for improving the
accuracy of CryoSat-2 maps of sea-ice thickness.
"We are making good progress," said Alain Hubert when contacted in his tent
on the ice with his satellite phone a few days ago. "We are now only 160 km
from the North Pole and taking snow-thickness measurements at regular
intervals along the way. Sometimes conditions are very difficult because of
the cold and wind. However, we feel the effort is worthwhile and we will
keep going."
As Alain and Dixie trek across the North Pole, a parallel campaign by
scientists from Germany, Norway and the UK is unfolding in the extreme
northern archipelago of Svalbard, Norway. On Thursday 12 April, a group of
eight scientists were transported by helicopter to the remote Austfonna ice
cap. As part of the CryoVex 2007 campaign, they will spend one month making
measurements of snow and ice properties along long transects that
criss-cross the ice sheet surface. Conditions on the ground are often
difficult, with high winds and low temperatures. The result is that
sometimes the instruments and equipment fail as the leader of the ground
team, Jon Ove Hagen from the University of Oslo, pointed out.
"We are currently moving our team from the depot at the bottom of the
Austfonna ice cap to the summit so that we can start our ground measurements
and support the airborne acquisition," said Jon Ove Hagen when contacted on
Monday 16 April. "Bad weather and a broken skidoo are simply things we need
to work around as we start our measurement programme."
As the ground experiments are carried out, measurements are also being taken
from the air by the Alfred Wegner Institute (AWI). The Dornier-228 aircraft
carries the ASIRAS instrument, which is an airborne version of the radar
altimeter instrument onboard CryoSat-2. By comparing the airborne data with
ground measurements scientists will test and verify novel methods for
retrieving ice-thickness change from the CryoSat-2 satellite mission ahead
of the launch.
"The first flight with ASIRAS looks good," says Veit Helm from AWI. "As soon
as the weather conditions are good and the ground teams are in place, we
look forward to our scientific flights and getting our hands dirty
processing and analysing the airborne radar altimeter data over Austfonna.
One fascinating aspect of such work is that the campaign actually allows us
to look into the future and see what the CryoSat-2 mission will see and
measure when it is launched."
The airborne work will continue until 24 April and the ground teams will
stay on the ice cap until the beginning of May. When the campaign draws to
an end, the challenge will then be to analyse the large volumes of data in
order to characterise and improve the CryoSat-2 measurements of changing ice
surfaces. In is only through such painstaking work that the challenge of
measuring ice thickness down to centimetre level from space can be achieved,
and in turn lead to a better understanding of the impact that changing
climate is having on the polar ice fields.
For more information please contact:
Malcolm Davidson
ESA CryoSat-2 Validation Manager
Malcolm.Davidson @ esa.int
[NOTE: Images and weblinks supporting this release are available at
http://www.esa.int/esaCP/SEMHIYLJC0F_index_1.html ]