The feedback between a warming climate and accelerated release of carbon currently frozen into permafrost around the Arctic is one of the grand challenges in current climate research. A study published this week in the Proceedings of the National Academy of Sciences of the USA by a team of researchers led by Stockholm University used radiocarbon dating of carbon in four large Siberian-Arctic rivers to pinpoint the patterns of old carbon release from permafrost across northern Eurasia.
Arctic permafrost and peatlands constitute frozen giants of the global carbon cycle. In the top few meters, the Arctic permafrost stores almost twice as much carbon as atmospheric CO2 and more than 200 times as much as atmospheric methane.
The large amounts of currently dormant permafrost carbon may be increasingly thawed and mobilized as climate warming progresses - and may then feed additional CO2 and methane into the atmosphere to accelerate climate warming.
This climate-carbon feedback is hard to assess as permafrost thaw differs widely across the Arctic and data from remote areas are limited. The new study provides a novel angle by using the radiocarbon signal of large rivers to understand permafrost thaw and carbon mobilization in their catchments.
"Rivers transport carbon from different sources in their catchments, including carbon mobilized from thawing permafrost or collapsing peat, as well as carbon from the soil surface. Radiocarbon dating helps us distinguish carbon from these different sources," says Birgit Wild, researcher at Stockholm University and lead author of the study.
Old carbon that has been preserved in deep permafrost or peat deposits for thousands of years thus contains less radiocarbon than modern carbon at the soil surface. The team of researchers calculated the flux of permafrost and peat carbon in the large Siberian rivers Ob, Yenisey, Lena and Kolyma by combining a database of radiocarbon in different deposits with monitoring of radiocarbon in the rivers over ten years and all seasons.
The study shows that permafrost and peat carbon contributed to only 12% of the dissolved organic carbon in these rivers, but to more than half of the particulate organic carbon. Seasonal differences suggest that gradual thaw of the seasonally frozen active layer and of surface permafrost is the main source of permafrost- and peat-derived carbon in dissolved form, whereas that in particulate form stems to a large extent from the collapse of deeper deposits that formed thousands of years ago.
Differences in the relative amounts of dissolved versus particulate permafrost and peat carbon between rivers were consistent with differences in the type and extent of permafrost in their basins.
"The radiocarbon signal of especially particulate organic carbon in rivers might be a sensitive tool to monitor carbon release from thawing permafrost over the coming decades," adds Örjan Gustafsson, professor at Stockholm University and leader of the team.
For further information and photos contact:
Dr. Birgit Wild, Department of Environmental Science and Analytical Chemistry and the Bolin Centre for Climate Research, Stockholm University, Email: email@example.com; Tel.: +46 76 561 00 02
Prof. Örjan Gustafsson, Department of Environmental Science and Analytical Chemistry and the Bolin Centre for Climate Research, Stockholm University, Email: firstname.lastname@example.org; Tel.: +46 70 324 73 17
Dr. Birgit Wild | EurekAlert!
Resolving the 'invisible' gold puzzle
02.05.2019 | GFZ GeoForschungsZentrum Potsdam, Helmholtz Centre
Scientists track giant ocean vortex from space
02.05.2019 | American Geophysical Union
An international collaboration with participation of the University of Bern has demonstrated for the first time in an interference experiment that antimatter particles also behave as waves besides having particle properties. This success paves the way to a new field of investigations of antimatter.
Matter waves constitute a crucial feature of quantum mechanics, where particles have wave properties in addition to particle characteristics. This...
A photodetector converts light into an electrical signal, causing the light to be lost. Researchers led by Tracy Northup at the University of Innsbruck have now built a quantum sensor that can measure light particles non-destructively. It can be used to further investigate the quantum properties of light.
Physicist Tracy Northup is currently researching the development of quantum internet at the University of Innsbruck. The American citizen builds interfaces...
It is only an inconspicuous piece of paper, but it is an important milestone for autonomous driving: At the end of 2018 the three partners from the joint research project RadarGlass applied for a patent for an innovative radar system. The Fraunhofer Institute for Laser Technology ILT from Aachen, the Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP from Dresden and the Institute of High Frequency Technology IHF of RWTH Aachen University have developed a coating process chain that enables radar sensors to be integrated in car headlights. After almost two years in development they have manufactured a working prototype.
Completely autonomous vehicles pose an enormous challenge for sensor technology because, in principle, the supporting system must hear, see and feel better...
Physics and Chemistry scholars from Hong Kong Baptist University (HKBU) have invented a new method which could speed up the drug discovery process and lead to the production of higher quality medicinal drugs which are purer and have no side effects. The technique, which is a world-first breakthrough, uses a specific nanomaterial layer to detect the target molecules in pharmaceuticals and pesticides in just five minutes.
The new HKBU invention can be applied to the drug discovery process, as well as the production and quality control stages of pharmaceutical manufacturing. It...
The use of potassium bromide in the production of graphene on a copper surface can lead to better results. When potassium bromide molecules arrange themselves between graphene and copper, it results in electronic decoupling. This alters the electrical properties of the graphene produced, bringing them closer to pure graphene, as reported by physicists from the universities of Basel, Modena and Munich in the journal ACS Nano.
Graphene consists of a layer of carbon atoms just one atom in thickness in a honeycomb pattern and is the subject of intensive worldwide research.
29.04.2019 | Event News
17.04.2019 | Event News
15.04.2019 | Event News
08.05.2019 | Earth Sciences
08.05.2019 | Life Sciences
08.05.2019 | Life Sciences