Andrew Yee
June 11th 05, 05:23 PM
ESA News
http://www.esa.int
10 June 2005
Space measurements of carbon offer clearer view of Earth's climate future
Follow the carbon -- this is the mantra of researchers seeking to understand
climate change and forecast its likely extent. A workshop heard how improved
detection of heat-trapping carbon dioxide from space promises to revolutionise
carbon cycle understanding.
This week saw more than 60 researchers from Europe, the United States and
Japan gather at ESRIN, ESA's establishment in Italy, for the three-day Carbon
from Space workshop, jointly organised by ESA, the International Geosphere
Biosphere Programme (IGBP), the Integrated Global Carbon Observations
Theme (IGCO) of the Integrated Global Observing Strategy (IGOS) and the
Global Carbon Project (GCP), with support from the European Union's CarboEurope
project.
"Direct satellite measurements of carbon dioxide will have as dramatic an impact
as the Hubble Space Telescope within the Earth science field," said Philippe Ciais
of the Laboratory for Climate Sciences and the Environment (LSCE) in Gif-sur-Yvette,
France.
"It should give us a completely new picture of something more or less completely
unknown, showing us the carbon flux across tropical areas such as South America
and Africa, where we basically have no data available right now."
The total number of carbon atoms on Earth is fixed -- they are exchanged between
the ocean, atmosphere, land and biosphere, through a set of processes known as
the carbon cycle.
The fact that human activities are pumping extra carbon dioxide into the atmosphere,
by burning carbon that has been locked up in the Earth, is well known -- the overall
concentration of this leading greenhouse gas has increased by a third since the
Industrial Revolution.
However, only around half of the extra carbon dioxide human activity sends into the
atmosphere stays there, unidentified 'sinks' on the land or ocean surface absorb the
rest. The rate of climate change would be much greater without this absorption, but
as long as its distribution, strength and variability remains uncertain, the
continuation of this effect cannot be taken for granted. In future, global
warming may shut it off, or even throw it into reverse.
Scientists create intricate numerical models to try and improve their understanding
of various segments of the carbon cycle within the Earth system, but significant
knowledge gaps remain, especially concerning the exchange of carbon or 'flux'
between the land surface and atmosphere.
Therefore another focus of discussion was how Earth Observation data on areas
including forest and vegetation cover, fires, especially the amount of vegetation
burned, biomass, humidity and land and sea photosynthesis can sharpen the
accuracy of terrestrial carbon models.
The workshop also discussed the issue of the complexity of the models and the
sparse nature of the data, focusing on 'data assimilation' -- the process by which
models make the most effective use of or 'learn' from the data available. A
number of examples were presented on aspects of this topic from the use of
continuous but sparse measurements of carbon flux, through better surface
characterisation to the incorporation of the currently available satellite observations
of carbon gases.
More precise information of where on the surface CO2 is being removed or emitted
would go a long way to shrinking areas of uncertainties within current models.
However ground-based carbon dioxide measurements are difficult and expensive
to perform, requiring for example, complex equipment with pressurised bottles,
lasers, spectrometers or towers measuring changes in carbon flux. There are only
about a hundred such measuring stations to cover the entire Earth.
"Even low-resolution satellite measurements would be a useful addition," explained
Peter Rayner of LSCE. "They would improve the accuracy of the carbon inversions
we perform -- where we take the concentration of CO2 in the atmosphere and follow
it backward to try and identify sources. We could also use the information as a
constraint on our models, ensuring they fit with observed reality."
While satellite observation of the greenhouse gas carbon monoxide is well
established, and last year Envisat's Scanning Imaging Absorption Spectrometer
for Atmospheric Chartography (SCIAMACHY) successfully observed atmospheric
methane, carbon dioxide represents a harder target than other greenhouse gases.
It is longer-lived and mixes well in the air, with the greatest variations
located right on the surface -- the far side of the atmosphere from any satellite
sensor.
Even so, the workshop heard that CO2 has been demonstrated experimentally
using satellite sensors including the Atmospheric Infrared Sounder (AIRS) aboard
NASA's weather and climate research satellite Aqua. A team from the University
of Bremen is also exploring the ability of SCIAMACHY to map horizontal and
vertical CO2 from space.
In the near future, the capacity to measure CO2 from space will increase, because
the Japan Aerospace Exploration Agency (JAXA) is gearing up for the launch of its
Greenhouse gases Observing Satellite (GOSAT) in 2008, while NASA prepares its
own CO2-detecting mission called the Orbiting Carbon Observatory (OCO) for 2007.
Principal Investigators Takashi Hamazaki of JAXA and David Crisp of NASA briefed
the workshop on these missions, both of which take the spectral 'fingerprints' of
reflected sunlight to measure carbon dioxide concentrations down to a 1%
accuracy -- around four parts per million molecules of air.
On the ESA side, the Agency is considering proposals for science missions studying
various aspects of the carbon cycle as part of the new round of Earth Explorers.
And a proposed new generation of operational Sentinel spacecraft would include
geostationary and orbiting atmospheric-observing satellites.
In addition, ESA is active in generating products to serve the carbon research
community through its 'GLOB' series of projects within its Data User Element
(DUE). GLOBCARBON, GLOBCOVER, GLOBAEROSOL and GLOBCOLOUR
aim to provide high quality information on the distribution of burned areas,
vegetation, particles in the atmosphere and the presence of carbon-fixing algae
in the oceans globally.
A joint activity between ESA, IGBP and GCP on model-data fusion, known as
the Optimisation Intercomparison Project (OptIC), will take products from
GLOBCARBON in particular to comparatively evaluate data assimilation
methods for the task of setting parameters for terrestrial carbon cycle and
biogeochemical models.
Peter Rayner remarked that the workshop was helpful as a means of knowing
what carbon-related data would be available in future, coordinating ground-based
activity in support and validation of these new missions, and also in highlighting
what gaps in knowledge remain to be tackled in future.
"The new spacecraft are reliant on reflected sunlight, for instance, but the carbon
cycle does not stop when areas are in darkness," he said. "Other methods will
need to be developed to learn more."
The three-day workshop was also significant as a contribution to the forthcoming
Integrated Global Carbon Observation (IGCO) Implementation Plan of the
Integrated Global Observing Strategy.
Intended for completion this September and aimed at an audience including
Earth Observation agencies and United Nations agencies including the United
Nations Environment Programme (UNEP) and the Food and Agriculture
Administration (FAO), the Plan will be a list of actions needed to create a
semi-operational carbon observation system during the coming decade.
Roger Dargaville of IGCO stated that satellite systems would be an important
part of the Implementation Plan, and the workshop had been a useful
opportunity to learn about latest developments.
Related news
* Envisat enables first global check of regional methane emissions
http://www.esa.int/esaEO/SEMY9FRMD6E_planet_0.html
* Global air pollution map produced by Envisat's SCIAMACHY
http://www.esa.int/esaEO/SEM340NKPZD_index_0.html
* Envisat Symposium Report Day 3: Satellites supporting Kyoto -- our
future is in our forests
http://www.esa.int/esaEO/SEMMUM0XDYD_index_0.html
In depth
* Carbon from Space workshop
http://www.congrex.nl/05c21/
* Data User Element
http://dup.esrin.esa.it
Related links
* International Geosphere-Biosphere Programme (IGBP)
http://www.igbp.kva.se/
* Global Carbon Project
http://www.globalcarbonproject.org
* IGOS
http://ioc.unesco.org/igospartners
* IGCO
http://ioc.unesco.org/igospartners/Carbon.htm
* CarboEurope
http://www.carboeurope.org/
* OptIC
http://www.globalcarbonproject.org/ACTIVITIES/OptIC.htm
* University of Bremen's Institute of Environmental Physics SCIAMACHY page
http://www.iup.physik.uni-bremen.de/sciamachy/
* Greenhouse gases Observing Satellite (GOSAT)
http://www.jaxa.jp/missions/projects/sat/eos/gosat/index_e.html
* Orbiting Carbon Observatory (OCO)
http://oco.jpl.nasa.gov/
[NOTE: Images supporting this release are available at
http://www.esa.int/esaEO/SEM8CC1DU8E_planet_1.html ]
http://www.esa.int
10 June 2005
Space measurements of carbon offer clearer view of Earth's climate future
Follow the carbon -- this is the mantra of researchers seeking to understand
climate change and forecast its likely extent. A workshop heard how improved
detection of heat-trapping carbon dioxide from space promises to revolutionise
carbon cycle understanding.
This week saw more than 60 researchers from Europe, the United States and
Japan gather at ESRIN, ESA's establishment in Italy, for the three-day Carbon
from Space workshop, jointly organised by ESA, the International Geosphere
Biosphere Programme (IGBP), the Integrated Global Carbon Observations
Theme (IGCO) of the Integrated Global Observing Strategy (IGOS) and the
Global Carbon Project (GCP), with support from the European Union's CarboEurope
project.
"Direct satellite measurements of carbon dioxide will have as dramatic an impact
as the Hubble Space Telescope within the Earth science field," said Philippe Ciais
of the Laboratory for Climate Sciences and the Environment (LSCE) in Gif-sur-Yvette,
France.
"It should give us a completely new picture of something more or less completely
unknown, showing us the carbon flux across tropical areas such as South America
and Africa, where we basically have no data available right now."
The total number of carbon atoms on Earth is fixed -- they are exchanged between
the ocean, atmosphere, land and biosphere, through a set of processes known as
the carbon cycle.
The fact that human activities are pumping extra carbon dioxide into the atmosphere,
by burning carbon that has been locked up in the Earth, is well known -- the overall
concentration of this leading greenhouse gas has increased by a third since the
Industrial Revolution.
However, only around half of the extra carbon dioxide human activity sends into the
atmosphere stays there, unidentified 'sinks' on the land or ocean surface absorb the
rest. The rate of climate change would be much greater without this absorption, but
as long as its distribution, strength and variability remains uncertain, the
continuation of this effect cannot be taken for granted. In future, global
warming may shut it off, or even throw it into reverse.
Scientists create intricate numerical models to try and improve their understanding
of various segments of the carbon cycle within the Earth system, but significant
knowledge gaps remain, especially concerning the exchange of carbon or 'flux'
between the land surface and atmosphere.
Therefore another focus of discussion was how Earth Observation data on areas
including forest and vegetation cover, fires, especially the amount of vegetation
burned, biomass, humidity and land and sea photosynthesis can sharpen the
accuracy of terrestrial carbon models.
The workshop also discussed the issue of the complexity of the models and the
sparse nature of the data, focusing on 'data assimilation' -- the process by which
models make the most effective use of or 'learn' from the data available. A
number of examples were presented on aspects of this topic from the use of
continuous but sparse measurements of carbon flux, through better surface
characterisation to the incorporation of the currently available satellite observations
of carbon gases.
More precise information of where on the surface CO2 is being removed or emitted
would go a long way to shrinking areas of uncertainties within current models.
However ground-based carbon dioxide measurements are difficult and expensive
to perform, requiring for example, complex equipment with pressurised bottles,
lasers, spectrometers or towers measuring changes in carbon flux. There are only
about a hundred such measuring stations to cover the entire Earth.
"Even low-resolution satellite measurements would be a useful addition," explained
Peter Rayner of LSCE. "They would improve the accuracy of the carbon inversions
we perform -- where we take the concentration of CO2 in the atmosphere and follow
it backward to try and identify sources. We could also use the information as a
constraint on our models, ensuring they fit with observed reality."
While satellite observation of the greenhouse gas carbon monoxide is well
established, and last year Envisat's Scanning Imaging Absorption Spectrometer
for Atmospheric Chartography (SCIAMACHY) successfully observed atmospheric
methane, carbon dioxide represents a harder target than other greenhouse gases.
It is longer-lived and mixes well in the air, with the greatest variations
located right on the surface -- the far side of the atmosphere from any satellite
sensor.
Even so, the workshop heard that CO2 has been demonstrated experimentally
using satellite sensors including the Atmospheric Infrared Sounder (AIRS) aboard
NASA's weather and climate research satellite Aqua. A team from the University
of Bremen is also exploring the ability of SCIAMACHY to map horizontal and
vertical CO2 from space.
In the near future, the capacity to measure CO2 from space will increase, because
the Japan Aerospace Exploration Agency (JAXA) is gearing up for the launch of its
Greenhouse gases Observing Satellite (GOSAT) in 2008, while NASA prepares its
own CO2-detecting mission called the Orbiting Carbon Observatory (OCO) for 2007.
Principal Investigators Takashi Hamazaki of JAXA and David Crisp of NASA briefed
the workshop on these missions, both of which take the spectral 'fingerprints' of
reflected sunlight to measure carbon dioxide concentrations down to a 1%
accuracy -- around four parts per million molecules of air.
On the ESA side, the Agency is considering proposals for science missions studying
various aspects of the carbon cycle as part of the new round of Earth Explorers.
And a proposed new generation of operational Sentinel spacecraft would include
geostationary and orbiting atmospheric-observing satellites.
In addition, ESA is active in generating products to serve the carbon research
community through its 'GLOB' series of projects within its Data User Element
(DUE). GLOBCARBON, GLOBCOVER, GLOBAEROSOL and GLOBCOLOUR
aim to provide high quality information on the distribution of burned areas,
vegetation, particles in the atmosphere and the presence of carbon-fixing algae
in the oceans globally.
A joint activity between ESA, IGBP and GCP on model-data fusion, known as
the Optimisation Intercomparison Project (OptIC), will take products from
GLOBCARBON in particular to comparatively evaluate data assimilation
methods for the task of setting parameters for terrestrial carbon cycle and
biogeochemical models.
Peter Rayner remarked that the workshop was helpful as a means of knowing
what carbon-related data would be available in future, coordinating ground-based
activity in support and validation of these new missions, and also in highlighting
what gaps in knowledge remain to be tackled in future.
"The new spacecraft are reliant on reflected sunlight, for instance, but the carbon
cycle does not stop when areas are in darkness," he said. "Other methods will
need to be developed to learn more."
The three-day workshop was also significant as a contribution to the forthcoming
Integrated Global Carbon Observation (IGCO) Implementation Plan of the
Integrated Global Observing Strategy.
Intended for completion this September and aimed at an audience including
Earth Observation agencies and United Nations agencies including the United
Nations Environment Programme (UNEP) and the Food and Agriculture
Administration (FAO), the Plan will be a list of actions needed to create a
semi-operational carbon observation system during the coming decade.
Roger Dargaville of IGCO stated that satellite systems would be an important
part of the Implementation Plan, and the workshop had been a useful
opportunity to learn about latest developments.
Related news
* Envisat enables first global check of regional methane emissions
http://www.esa.int/esaEO/SEMY9FRMD6E_planet_0.html
* Global air pollution map produced by Envisat's SCIAMACHY
http://www.esa.int/esaEO/SEM340NKPZD_index_0.html
* Envisat Symposium Report Day 3: Satellites supporting Kyoto -- our
future is in our forests
http://www.esa.int/esaEO/SEMMUM0XDYD_index_0.html
In depth
* Carbon from Space workshop
http://www.congrex.nl/05c21/
* Data User Element
http://dup.esrin.esa.it
Related links
* International Geosphere-Biosphere Programme (IGBP)
http://www.igbp.kva.se/
* Global Carbon Project
http://www.globalcarbonproject.org
* IGOS
http://ioc.unesco.org/igospartners
* IGCO
http://ioc.unesco.org/igospartners/Carbon.htm
* CarboEurope
http://www.carboeurope.org/
* OptIC
http://www.globalcarbonproject.org/ACTIVITIES/OptIC.htm
* University of Bremen's Institute of Environmental Physics SCIAMACHY page
http://www.iup.physik.uni-bremen.de/sciamachy/
* Greenhouse gases Observing Satellite (GOSAT)
http://www.jaxa.jp/missions/projects/sat/eos/gosat/index_e.html
* Orbiting Carbon Observatory (OCO)
http://oco.jpl.nasa.gov/
[NOTE: Images supporting this release are available at
http://www.esa.int/esaEO/SEM8CC1DU8E_planet_1.html ]