Carbon cycle dynamics in response to permafrost degradation is a ‘hot topic’ in northern research. We are particularly interested in greenhouse gases (CO2, CH4) emitted from ‘thermokarst’ aquatic ecosystems, i.e. ponds and lakes formed by the thawing of ice-rich permafrost. Such thawing results in the atmospheric release (as CO2 and CH4) of old carbon formerly trapped frozen in the ground. One of the main challenges is to sample efficiently these gases, especially small bubbles rising through the water column.
In collaboration with colleagues from the Institut National de la Recherche Scientifique (INRS, Quebec QC) and Université de Montréal, we participated to the design, fabrication and field installation of funnels used for sampling gas bubbles escaping from the bottom of ponds and lakes of Bylot Island, Nunavut (see photos). These funnels are almost completely made of common hardware store materials and are thus quite affordable. We installed the funnels in different types of ponds and lakes representative of the tundra landscape on Bylot Island: Ice-wedge polygon ponds, ice-wedge troughs, and thermokarst and glacial lakes. The results were recently published in an international open-access journal (see the links below).
We are also studying the historical evolution of these aquatic systems during the past several centuries to millennia based on the analysis of lake sediment archives, a discipline called ‘paleolimnology’. It is important to study how these systems reacted to climate change in the past, in order to better understand how they are now responding to this change, and how they will evolve in the future.
Study Site Location:
Qarlikturvik Valley, Bylot Island (73° 09’ N; 79° 58’ W)
Parks Canada (Pond Inlet)
Nattinak Visitor’s Centre (Pond Inlet)
Frédéric Bouchard, PhD
Université de Montréal, Department of Geography
Photo 1. Our study site: Qarlikturvik Valley (Bylot Island, NU).
Photo credit: Isabelle Laurion, INRS-ETE.
Photo 2: Sampling greenhouse gas bubbles with homemade funnels.
Photo credit: Vilmantas Preskienis, INRS-ETE.
Link to Publications:
Recently published paper: