Permafrost can be found in the northern and southern hemisphere at high latitudes or high elevations it is defined as ground that has been at or below 0° C for at least two consecutive years here you can see the recent permafrost coverage of the northern hemisphere in total permafrost underlies
20 to 25% of the land surface of the Earth the global permafrost regions contain about 1,700 gigatons of carbon in form of buried and frozen organic material which represents nearly twice as much carbon as currently present in the atmosphere with the recently increasing temperatures this carbon sink might change into a source increasing
Microbial decomposition fuels carbon mineralization and greenhouse gas production which causes again a temperature increase a runaway feedback loop there are three consecutive thawing stages of permafrost Pulsa bog and fin Pulsa vegetation is dominated by shrubs mosses and lyans you don’t even need rubber boots to walk on it as the
Thawing goes on the Pulsa sites collapse get wetter and turn into bogs typical vegetation of bog sites consists of mosses and sedges the final stage are fully thawed F often covered with fluffy cotton grass here the water rises up to your knees which often leads to wet feet even in rubber
Boots one important influencing Factor on the emission of greenhouse gases in permafrost regions is the iron related Redux cycling organic carbon might either be trapped at iron mineral surfaces or mobilized by microbial iron reduction due to Rising water tables along the permafrost thaw gradient an increase in Iron dissolution and
Therefore also higher emissions of carbon dioxide and methane are expected the permafrost group at the University of tubingen is investigating the relation between iron cycling and the mobilization of carbon in permafrost systems they conduct lab-based studies and fieldwork in stoal and Meyer which is in abisco Sweden more precisely they
Take poor water samples through Ryon Samplers analyze the iron flocks that arise in the ponds and take drill cores to analyze the soil moreover gas Chambers can provide information about the role of plants in permafrost systems permafrost systems are highly susceptible to thawing with climate warming in the most severe RCP scenario
Which includes a global temperature rise of 4.8 de C near surface permafrost area could decrease by up to 99% and even with a moderate temperature rise of less than 2° C up to 2/3 of the permafrost might disappear when one thinks of the large amounts of carbon buried within them it
Becomes clear that permafrost areas could switch from a carbon sink to one of the biggest carbon sources on our Earth the increasing carbon dioxide and methane emissions would accelerate climate change and set the stage for a vicious cycle the permafrost carbon feedback studying the Dynamics in a thawing permafrost system could help us
Find the triggers understand the relationships and predict the consequences of global Warming A