Featured Research

from universities, journals, and other organizations

Space Measurements Of Carbon Offer Clearer View Of Earth's Climate Future

Date:
June 13, 2005
Source:
European Space Agency
Summary:
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.

NASA and JAXA's carbon-dedicated missions, due to launch in 2007 and 2008 respectively. NASA's Orbiting Carbon Observatory (OCO) is shown above JAXA's Greenhouse gases Observing Satellite (GOSAT). Both spacecraft will be able to observe atmospheric carbon dioxide, improving the accuracy of carbon models.
Credit: s: NASA/JAXA

"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.


Story Source:

The above story is based on materials provided by European Space Agency. Note: Materials may be edited for content and length.


Cite This Page:

European Space Agency. "Space Measurements Of Carbon Offer Clearer View Of Earth's Climate Future." ScienceDaily. ScienceDaily, 13 June 2005. <www.sciencedaily.com/releases/2005/06/050612111201.htm>.
European Space Agency. (2005, June 13). Space Measurements Of Carbon Offer Clearer View Of Earth's Climate Future. ScienceDaily. Retrieved August 21, 2014 from www.sciencedaily.com/releases/2005/06/050612111201.htm
European Space Agency. "Space Measurements Of Carbon Offer Clearer View Of Earth's Climate Future." ScienceDaily. www.sciencedaily.com/releases/2005/06/050612111201.htm (accessed August 21, 2014).

Share This




More Earth & Climate News

Thursday, August 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Unsustainable Elephant Poaching Killed 100K In 3 Years

Unsustainable Elephant Poaching Killed 100K In 3 Years

Newsy (Aug. 20, 2014) Poachers have killed 100,000 elephants between 2010 and 2012, as the booming ivory trade takes its toll on the animals in Africa. Video provided by Newsy
Powered by NewsLook.com
Charter Schools Alter Post-Katrina Landscape

Charter Schools Alter Post-Katrina Landscape

AP (Aug. 20, 2014) Nine years after Hurricane Katrina, charter schools are the new reality of public education in New Orleans. The state of Louisiana took over most of the city's public schools after the killer storm in 2005. (Aug. 20) Video provided by AP
Powered by NewsLook.com
Green Power Blooms as Japan Unveils 'hydrangea Solar Cell'

Green Power Blooms as Japan Unveils 'hydrangea Solar Cell'

AFP (Aug. 19, 2014) A solar cell that resembles a flower is offering a new take on green energy in Japan, where one scientist is searching for renewables that look good. Duration: 01:29 Video provided by AFP
Powered by NewsLook.com
Disquieting Times for Malaysia's 'fish Listeners'

Disquieting Times for Malaysia's 'fish Listeners'

AFP (Aug. 19, 2014) Malaysia's last "fish listeners" -- practitioners of a dying local art of listening underwater to locate their quarry -- try to keep the ancient technique alive in the face of industrial trawling and the depletion of stocks. Duration: 02:29 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins