Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


NASA scientists discover spring thaw makes a difference



Classification of frozen (blue) and thawed (red) regions across Alaska on April 22, 2000. This classification was derived using data from NASA’s SeaWinds scatterometer flown on the QuikSCAT satellie. Scientists are using data from SeaWinds to quantify freeze/thaw transitions across northern landscapes, and the associated ecological and hydrologic response of northern ecosystems. CREDIT: NASA JPL

Using a suite of microwave remote sensing instruments aboard satellites, scientists at NASA’s Jet Propulsion Laboratory (JPL), Pasadena, Calif., and the University of Montana, Missoula, have observed a recent trend of earlier thawing across the northern high latitudes.

This regional thawing trend, advancing almost one day a year since 1988, has the potential to alter the cycle of atmospheric carbon dioxide intake and release by vegetation and soils across the region, potentially resulting in changes in Earth’s climate. The lengthening growing season appears to be promoting more carbon uptake by the vegetation than is being released into the atmosphere for the region. How long this trend will occur depends on whether soils continue to remain cold and wet.

Research scientists have been studying freeze/thaw dynamics in North America and Eurasia’s boreal forests and tundra to decipher effects on the timing and length of the growing season. These regions encompass almost 30 percent of global land area. They store a major portion of Earth’s carbon in vegetation, in seasonally frozen and permafrost soils. Large expanses of boreal forest and tundra are underlain by permafrost, a layer of permanently frozen soil found underneath the active, seasonally thawed soil.

"Frozen soil can store carbon for hundreds to thousands of years," said lead author Dr. Kyle McDonald of JPL, "but when the permafrost thaws and begins to dry out, it releases the carbon back into the atmosphere." The concern is that eventually carbon released from the soil will prevail over the amount being taken in by growing plants. Carbon dioxide levels in the atmosphere would increase at an accelerated rate, fostering even greater warming of the region and affecting global climate.

With help from NASA radars and other orbiting satellite microwave remote sensing instruments, including the National Oceanic and Atmospheric Administration’s Special Scanning Microwave/Imager, scientists can monitor growing season dynamics of the global boreal forest and tundra daily. These instruments sense the electrical properties of water in the landscape, allowing scientists to determine exactly when and where the springtime thaw occurs.

Because of the large extent and location of boreal forest and tundra, and the global reservoir of carbon stored in their vegetation and soils, this region is extremely sensitive to environmental change. It has the capacity to dramatically impact Earth’s climate.

"If global climate change is happening, here’s where you would expect to see it first," McDonald said.

As the research team observed, the earlier the spring thaw occurs, the longer the growing season. These changes appear to be promoting plant growth for the region. The longer growing season allows plants to remove more carbon dioxide from the atmosphere over a longer period of time.

Carbon dioxide is an important greenhouse gas that, if left in the atmosphere, would promote additional warming. The plants release oxygen and store the carbon as biomass that eventually decomposes and transfers the carbon into the soil. Soil microbes decompose dead plant material, returning a portion of the soil carbon back into the atmosphere. The rate which soil microbes decompose plant material and release carbon to the atmosphere is also very sensitive to temperature. It could potentially increase with warming temperatures and longer growing seasons.

From this general study, McDonald, Dr. John Kimball of the University of Montana, and JPL’s Erika Podest have lead three different investigations, each focusing on different noticeable changes in the boreal region. Results of three related papers on this research will be presented to the American Geophysical Union’s Fall Meeting this week in San Francisco.

The research is funded by NASA’s Earth Science Enterprise. The Enterprise is dedicated to understanding the Earth as an integrated system and applying Earth System Science to improve prediction of climate, weather, and natural hazards using the unique vantage point of space. The California Institute of Technology, Pasadena, manages JPL for NASA.

Alan Buis | GSFC
Further information:

More articles from Earth Sciences:

nachricht Wandering greenhouse gas
16.03.2018 | Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung

nachricht Unique Insights into the Antarctic Ice Shelf System
14.03.2018 | Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Tiny implants for cells are functional in vivo

For the first time, an interdisciplinary team from the University of Basel has succeeded in integrating artificial organelles into the cells of live zebrafish embryos. This innovative approach using artificial organelles as cellular implants offers new potential in treating a range of diseases, as the authors report in an article published in Nature Communications.

In the cells of higher organisms, organelles such as the nucleus or mitochondria perform a range of complex functions necessary for life. In the networks of...

Im Focus: Locomotion control with photopigments

Researchers from Göttingen University discover additional function of opsins

Animal photoreceptors capture light with photopigments. Researchers from the University of Göttingen have now discovered that these photopigments fulfill an...

Im Focus: Surveying the Arctic: Tracking down carbon particles

Researchers embark on aerial campaign over Northeast Greenland

On 15 March, the AWI research aeroplane Polar 5 will depart for Greenland. Concentrating on the furthest northeast region of the island, an international team...

Im Focus: Unique Insights into the Antarctic Ice Shelf System

Data collected on ocean-ice interactions in the little-researched regions of the far south

The world’s second-largest ice shelf was the destination for a Polarstern expedition that ended in Punta Arenas, Chile on 14th March 2018. Oceanographers from...

Im Focus: ILA 2018: Laser alternative to hexavalent chromium coating

At the 2018 ILA Berlin Air Show from April 25–29, the Fraunhofer Institute for Laser Technology ILT is showcasing extreme high-speed Laser Material Deposition (EHLA): A video documents how for metal components that are highly loaded, EHLA has already proved itself as an alternative to hard chrome plating, which is now allowed only under special conditions.

When the EU restricted the use of hexavalent chromium compounds to special applications requiring authorization, the move prompted a rethink in the surface...

All Focus news of the innovation-report >>>



Industry & Economy
Event News

Virtual reality conference comes to Reutlingen

19.03.2018 | Event News

Ultrafast Wireless and Chip Design at the DATE Conference in Dresden

16.03.2018 | Event News

International Tinnitus Conference of the Tinnitus Research Initiative in Regensburg

13.03.2018 | Event News

Latest News

A new kind of quantum bits in two dimensions

19.03.2018 | Physics and Astronomy

Scientists have a new way to gauge the growth of nanowires

19.03.2018 | Materials Sciences

Virtual reality conference comes to Reutlingen

19.03.2018 | Event News

Science & Research
Overview of more VideoLinks >>>