Andrew Yee[_1_]
May 6th 08, 01:51 AM
ESA News
http://www.esa.int
5 May 2008
ESA contributes to ocean carbon cycle research
The Earth's oceans play a vital role in the carbon cycle, making it
imperative that we understand marine biological activity enough to predict
how our planet will react to the extra 25,000 million tonnes of carbon
dioxide humans are pumping into the atmosphere annually.
The colour of oceanic seawater depends largely on the number of microscopic
phytoplankton, marine plants that live in the well-lit surface layer. Just
like land-based plants, phytoplankton accumulate carbon dioxide during
photosynthesis and store it in their tissues, making them potentially
important carbon sinks.
While phytoplankton themselves are individually microscopic, the chlorophyll
they collectively contain colours the ocean's waters, which provides a means
of detecting these tiny organisms from space with dedicated ocean colour
sensors.
To support ocean carbon cycle research, ESA's GlobColour project has merged
55 terabytes of data from three state-of-the-art instruments aboard
different satellites, including MERIS aboard ESA's Envisat, MODIS aboard
NASA's Aqua and SeaWiFS aboard GeoEye's Orbview-2, to produce a 10-year
dataset of global ocean colour stretching to 2007.
"I am quite impressed by the work ESA has done so far within GlobColour,"
said Dr Cyril Moulin of the International Ocean Carbon Coordination Project
(IOCCP). "This 10-year dataset is going to be very useful for carbon studies
and global modelling."
The ocean colour datasets are freely available to the public via the
GlobColour website. A new web interface, Hermes, is available which allows
users to select a time period, spatial region and product type. Based on
this input, the system extracts the appropriate ocean colour products for
users to download.
By combining observations from multiple sensors, GlobColour brings several
benefits over existing products, such as better sampling of the daily
variability, smaller errors because of the larger amount of data and reduced
instrumental biases.
To guarantee the data set is of good quality, the data have undergone an
intensive validation process by comparing measurements from in-situ buoys.
The conclusion was that the error statistics of the merged data are better
than data from the three individual sensors.
In addition to aiding carbon cycle research, ocean colour data can provide
oceanographers with the information they need to monitor the state of the
oceans for other applications, such as for the fisheries and aquaculture
industries.
GlobColour, part of ESA's Data User Element (DUE), will begin providing
near-real time ocean colour observations to support this type of operational
oceanography from mid-2008.
This service will continue well into the future, thanks to the European
Commission (EC), who will continue production of the GlobColour time series
from 2009 as part of the Marine Core Service of the GMES (Global Monitoring
for Environment and Security) initiative.
"We need to sustain an international effort to make sure we can link one
satellite dataset to another to build the long-time series that we need to
distinguish change from cycles, and GlobColour is definitely a significant
step in that perspective," said Dr James Yoder, Chair of the International
Ocean-Colour Coordinating Group (IOCCG).
Marine Core Service and GMES
The Marine Core Service will deliver systematic reference information on the
state of the global ocean and European Union seas by providing observational
and model data, real-time predictions and ocean scenario simulations.
GMES -- a joint initiative of the EC and ESA -- responds to Europe's needs
for geo-spatial information services by bringing together the capacity of
Europe to collect and manage data and information on the environment and
civil security, for the benefit of European citizens.
[NOTE: Images supporting this release are available at
http://www.esa.int/esaCP/SEMQMYTQMFF_index_1.html ]
http://www.esa.int
5 May 2008
ESA contributes to ocean carbon cycle research
The Earth's oceans play a vital role in the carbon cycle, making it
imperative that we understand marine biological activity enough to predict
how our planet will react to the extra 25,000 million tonnes of carbon
dioxide humans are pumping into the atmosphere annually.
The colour of oceanic seawater depends largely on the number of microscopic
phytoplankton, marine plants that live in the well-lit surface layer. Just
like land-based plants, phytoplankton accumulate carbon dioxide during
photosynthesis and store it in their tissues, making them potentially
important carbon sinks.
While phytoplankton themselves are individually microscopic, the chlorophyll
they collectively contain colours the ocean's waters, which provides a means
of detecting these tiny organisms from space with dedicated ocean colour
sensors.
To support ocean carbon cycle research, ESA's GlobColour project has merged
55 terabytes of data from three state-of-the-art instruments aboard
different satellites, including MERIS aboard ESA's Envisat, MODIS aboard
NASA's Aqua and SeaWiFS aboard GeoEye's Orbview-2, to produce a 10-year
dataset of global ocean colour stretching to 2007.
"I am quite impressed by the work ESA has done so far within GlobColour,"
said Dr Cyril Moulin of the International Ocean Carbon Coordination Project
(IOCCP). "This 10-year dataset is going to be very useful for carbon studies
and global modelling."
The ocean colour datasets are freely available to the public via the
GlobColour website. A new web interface, Hermes, is available which allows
users to select a time period, spatial region and product type. Based on
this input, the system extracts the appropriate ocean colour products for
users to download.
By combining observations from multiple sensors, GlobColour brings several
benefits over existing products, such as better sampling of the daily
variability, smaller errors because of the larger amount of data and reduced
instrumental biases.
To guarantee the data set is of good quality, the data have undergone an
intensive validation process by comparing measurements from in-situ buoys.
The conclusion was that the error statistics of the merged data are better
than data from the three individual sensors.
In addition to aiding carbon cycle research, ocean colour data can provide
oceanographers with the information they need to monitor the state of the
oceans for other applications, such as for the fisheries and aquaculture
industries.
GlobColour, part of ESA's Data User Element (DUE), will begin providing
near-real time ocean colour observations to support this type of operational
oceanography from mid-2008.
This service will continue well into the future, thanks to the European
Commission (EC), who will continue production of the GlobColour time series
from 2009 as part of the Marine Core Service of the GMES (Global Monitoring
for Environment and Security) initiative.
"We need to sustain an international effort to make sure we can link one
satellite dataset to another to build the long-time series that we need to
distinguish change from cycles, and GlobColour is definitely a significant
step in that perspective," said Dr James Yoder, Chair of the International
Ocean-Colour Coordinating Group (IOCCG).
Marine Core Service and GMES
The Marine Core Service will deliver systematic reference information on the
state of the global ocean and European Union seas by providing observational
and model data, real-time predictions and ocean scenario simulations.
GMES -- a joint initiative of the EC and ESA -- responds to Europe's needs
for geo-spatial information services by bringing together the capacity of
Europe to collect and manage data and information on the environment and
civil security, for the benefit of European citizens.
[NOTE: Images supporting this release are available at
http://www.esa.int/esaCP/SEMQMYTQMFF_index_1.html ]