Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Ocean Plant Life Slows down and Absorbs Less Carbon

17.09.2003


Distributions of Ocean Net Primary Productivity (1997-2002)

The image shows ocean net primary productivity distributions from the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) data on the OrbView-2 satellite (1997-2002). The units are in grams of Carbon per meter squared per year. Light gray areas indicate missing data. Credit: Images by Robert Simmon, NASA GSFC Earth Observatory, based on data provided by Watson Gregg, NASA GSFC.


Difference in Distributions of Ocean Net Primary Productivity between 1997-2002 and 1979-1986 Data

The image shows the difference in ocean net primary productivity between the SeaWiFS era (1997-2002) and the CZCS era (1979-1986). To obtain the differences, the CZCS results were subtracted from the SeaWiFS results. The units are in grams of Carbon per meter squared per year. Light gray areas indicate missing data. Credit: Images by Robert Simmon, NASA GSFC Earth Observatory, based on data provided by Watson Gregg, NASA GSFC.

Plant life in the world’s oceans has become less productive since the early 1980s, absorbing less carbon, which may in turn impact the Earth’s carbon cycle, according to a study that combines NASA satellite data with NOAA surface observations of marine plants.

Microscopic ocean plants called phytoplankton account for about half the transfer of carbon dioxide (CO2) from the environment into plant cells by photosynthesis. Land plants pull in the other half. In the atmosphere, CO2 is a heat- trapping greenhouse gas.

Watson Gregg, a NASA GSFC researcher and lead author of the study, finds that the oceans’ net primary productivity (NPP) has declined more than 6 percent globally over the last two decades, possibly as a result of climatic changes. NPP is the rate at which plant cells take in CO2 during photosynthesis from sunlight, using the carbon for growth. The NASA funded study appears in a recent issue of Geophysical Research Letters.

"This research shows ocean primary productivity is declining, and it may be a result of climate changes such as increased temperatures and decreased iron deposition into parts of the oceans. This has major implications for the global carbon cycle," Gregg said. Iron from trans-continental dust clouds is an important nutrient for phytoplankton, and when lacking can keep populations from growing.

Gregg and colleagues used two datasets from NASA satellites: one from the Coastal Zone Color Scanner aboard NASA’s Nimbus- 7 satellite (1979-1986); and another from Sea-viewing Wide Field-of-view Sensor data on the OrbView-2 satellite (1997- 2002).

The satellites monitor the green pigment in plants, or chlorophyll, which leads to estimates of phytoplankton amounts. The older data was reanalyzed to conform to modern standards, which helped make the two data records consistent with each other. The sets were blended with surface data from NOAA research vessels and buoys to reduce errors in the satellite records and to create an improved estimate of NPP.

The authors found nearly 70 percent of the NPP global decline per decade occurred in the high latitudes (above 30 degrees). In the North Pacific and North Atlantic basins, phytoplankton bloom rapidly in high concentrations in spring, leading to shorter, more intense lifecycles. In these areas, plankton quickly dies and can sink to the ocean floor, creating a potential pathway of carbon from the atmosphere into the deep ocean.

In the high latitudes, rates of plankton growth declined by 7 percent in the North Atlantic basin, 9 percent in the North Pacific basin, and 10 percent in the Antarctic basin when comparing the 1980s dataset with the late 1990s observations.

The decline in global ocean NPP corresponds with an increase in global sea surface temperatures of 0.36 degrees Fahrenheit (F) (0.2 degrees Celsius (C)) over the last 20 years. Warmer water creates more distinct ocean layers and limits mixing of deeper nutrient-rich cooler water with warmer surface water. The lack of rising nutrients keeps phytoplankton growth in check at the surface.

The North Atlantic and North Pacific experienced major increases in sea surface temperatures: 0.7 degrees C (1.26 F) and 0.4 degrees C (0.72 F) respectively. In the Antarctic, there was less warming, but lower NPP was associated with increased surface winds. These winds caused plankton to mix downward, cutting exposure to sunlight.

Also, the amount of iron deposited from desert dust clouds into the global oceans decreased by 25 percent over two decades. These dust clouds blow across the oceans. Reductions in NPP in the South Pacific were associated with a 35 percent decline in atmospheric iron deposition.

"These results illustrate the complexities of climate change, since there may be one or more processes, such as changes in temperature and the intensity of winds, influencing how much carbon dioxide is taken up by photosynthesis in the oceans," said co-author Margarita Conkright, a scientist at NOAA’s National Oceanographic Data Center, Silver Spring, Md.

Other recent NASA findings have shown land cover on Earth has actually been greening. For information and images on the Internet, visit: www.nasa.gov/home/hqnews/2003/jun/HQ_03182_green_garden.html

Krishna Ramanujan | GSFC
Further information:
http://www.gsfc.nasa.gov/topstory/2003/0815oceancarbon.html
http://www.nasa.gov/home/hqnews/2003/jun/HQ_03182_green_garden.html

More articles from Ecology, The Environment and Conservation:

nachricht A new indicator for marine ecosystem changes: the diatom/dinoflagellate index
21.08.2017 | Leibniz-Institut für Ostseeforschung Warnemünde

nachricht Value from wastewater
16.08.2017 | Hochschule Landshut

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

Cholesterol-lowering drugs may fight infectious disease

22.08.2017 | Health and Medicine

Meter-sized single-crystal graphene growth becomes possible

22.08.2017 | Materials Sciences

Repairing damaged hearts with self-healing heart cells

22.08.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>