Vast areas on the Northern Hemisphere are covered by tundra. Here, dwarf shrubs, sedges, mosses etc. thrive on top of permafrost in areas where only the uppermost soil layer thaws during the short Arctic summer.
Zackenberg Research Station in Northeast Greenland was established in 1995 and has since become one of the best platforms for research and monitoring in the Arctic thanks to the ongoing monitoring programs. The buildings in Zackenberg are owned by Greenland's Self Government, whereas operation and maintenance are undertaken by Aarhus University.
Credit: Henrik Spanggård Munch, Aarhus University
New studies show that the tundra may become a source of CO2 in the future. Researcher Magnus Lund from Aarhus University explains:
"The soil below the tundra contains very large quantities of carbon – more than twice as much as is present in the planet's entire atmosphere. Therefore, we would like to know if the carbon will stay put – or if it will be released into the atmosphere as CO2 or methane as the climate warms."
Since 2000, researchers in Zackenberg in Northeast Greenland have therefore studied the carbon balance by exploring the following two figures:
1) The amount of carbon released in the form of CO2 as living organisms respire
2) The amount of carbon being stored in plants owing to photosynthesis.
Once you have established the two figures, it is possible to calculate if the tundra is a source of CO2 or if it acts as a sink absorbing carbon and storing it in living plants or in the peat layer.
"We can see that the annual release of CO2 from living organisms increases linearly as the temperature increases, measured as the average temperature in July. However, it seems that the ability of the photosynthesis to assimilate carbon stops increasing when the temperature in July rises above approx. seven degrees Celsius, which has occurred several times in past years. This means that the tundra may become a CO2 source if the current strong climate warming continues as expected," says Magnus Lund, before pointing out that the fear that the tundra can develop into a source of CO2 is based on a very limited number of measurements.
"It's a problem in the Arctic that we don't perform measurements at enough locations. The variation between locations is substantial both for CO2 and not least for methane. In Greenland, we measure near Nuuk and in Zackenberg, where we collect measurements from a relatively dry heath and from a moist fen area. A new station is also being established at Station Nord in the northernmost part of Greenland."
Methane remains more important
Magnus Lund emphasises that, in decades to come, from an Arctic perspective, methane will remain the primary contributor to Earth's greenhouse gas budget. In 2007, researchers from the Zackenberg research station in Northeast Greenland made a surprising discovery: In autumn, when the surface of the tundra freezes and ice is formed, large quantities of the powerful greenhouse gas methane are released. In fact, the quantities released were so large, that the annual methane emissions had to be doubled in the calculation of the tundra's methane budget.
Methane is a powerful greenhouse gas, its effect is 20-25 times as strong as that of CO2. Methane, therefore, still plays a central role for the research performed at Zackenberg.
Soil moisture crucial
Recent studies have shown that the formation of methane is closely linked to the tundra's water content - as implied by the term "swamp gas". The more water is present in the tundra, the more methane is formed. And vice versa, where there is less water, the presence of oxygen will provide the basis for formation of CO2. In this way, the soil's water content plays an important role in determining what will happen with the carbon below the tundra.
Areas that become drier will give rise to increased CO2 emissions, whereas areas that become more moist will cause the emissions of methane to increase. The water balance is affected by the temperature and precipitation, but also by the soil's content of ice.
Among other things, researchers are now working to establish how and when the methane released in autumn is formed, and if this involves new or old carbon.
Zackenberg Research Station in Northeast Greenland was established in 1995 and has since become one of the best platforms for research and monitoring in the Arctic thanks to the ongoing monitoring programmes. The buildings in Zackenberg are owned by Greenland's Self Government, whereas operation and maintenance are undertaken by Aarhus University.
Photo: Measuring equipment
Measuring equipment in Rylekæret fen, Zackenberg. The lawn-chair-like devices at the end of the boardwalk measure the exchange of methane and CO2 between the fen and the atmosphere. To the left: a gradient system for measurement of the exchange of methane between the tundra and the atmosphere. Even though many of the measurements can now be made automatically, it is necessary to check the equipment regularly to ensure that everything is in good working order. Photo: Laura Helene Rasmussen, Aarhus University.
ContactResearcher Magnus Lund
Revisiting factors controlling methane emissions from high-Arctic tundra. M. Mastepanov et al. 2013, Biogeosciences, vol. 10, 5139–5158, 2013, doi:10.5194/bg-10-5139-2013
Researchers predict a greener Greenland, http://scitech.au.dk/en/current-affairs/news/show/artikel/researchers-predict-a-greener-greenland/ (news article from Aarhus University)
Zackenberg Research Station, http://www.zackenberg.dk/
PLANET EARTH IS GETTING HOTTER- BUT WHAT CAN WE DO ABOUT IT? Theme on Climate Change at Aarhus University, http://newsroom.au.dk/en/themes/theme-climate-change/
Magnus Lund | EurekAlert!
Water - as the underlying driver of the Earth’s carbon cycle
17.01.2017 | Max-Planck-Institut für Biogeochemie
Modeling magma to find copper
13.01.2017 | Université de Genève
Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.
While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...
Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales
Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...
Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.
As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...
At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).
Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...
Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.
The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...
10.01.2017 | Event News
09.01.2017 | Event News
05.01.2017 | Event News
17.01.2017 | Earth Sciences
17.01.2017 | Materials Sciences
17.01.2017 | Architecture and Construction