Jorien Vonk
Each new piece of the puzzle to be solved is important
Thawing permafrost in polar regions and its effect on climate
Conversion of Yedoma into greenhouse gases
Jorien Vonk studies Yedoma. This is a very ancient form of permafrost, which contains as much carbon as is present in all the living biomass on Earth combined. These deposits in Siberia have been frozen for thousands of years, since the last ice age.
The present climate change, which is much more intense in the Arctic regions, could thaw the Yedoma and convert it into greenhouse gases.
Effect is stronger than expected
Earlier experiments conducted by Jorien Vonk and colleagues in Siberia reveal that the degradation of thawing Yedoma appears to be proceeding very rapidly. The only thing that is still unclear is the precise speed and scale of this phenomenon. "With the help of isotopes, I intend to find out how much Yedoma is being released into the rivers and coastal waters of north-eastern Siberia.
Due to it's old age and the special formation process of Yedoma permafrost, the isotope fingerprint (from hydrogen, oxygen and carbon isotopes) of Yedoma is very different from that of modern soils and vegetation. By measuring the organic matter in rivers and coastal waters, I can see how much Yedoma is released and how quickly it is broken down." A recently published article by Jorien in 'Nature' shows that erosion of Yedoma along the Siberian coast is much stronger than what we had first thought, and that the rate of conversion into the greenhouse gas CO2 is also much higher.
Solving a piece of the puzzle
Our knowledge of polar regions and how they affect our climate is still inadequate. Hence, it still is inclear how large the effect of CO2 emissions from thawing permafrost is on the greenhouse effect. "This is why each new piece of the puzzle to be solved is important and helps us to assess what is going to happen in the future."
Dr Jorien Vonk is a Researcher in Geochemistry. In July 2012, she received a Veni grant of 250,000 euros.