Climatic drivers of retrogressive thaw slump activity and resulting sediment and carbon release to the nearshore zone of Herschel Island, Yukon Territory, Canada

The Yukon Coast in Canada is an ice-rich permafrost coast and highly sensitive to changing environmental conditions. Retrogressive thaw slumps are a common thermoerosion feature along this coast, and develop through the thawing of exposed ice-rich permafrost on slopes and removal of accumulating debris. They contribute large amounts of sediment, including organic carbon and nitrogen, to the nearshore zone. The objective of this study was to 1) identify the climatic and geomorphological drivers of sediment-meltwater release, 2) quantify the amount of released meltwater, sediment, organic carbon and nitrogen, and 3) project the evolution of sediment-meltwater release of retrogressive thaw slumps in a changing future climate. The analysis is based on data collected over 18 days in July 2013 and 18 days in August 2012. A cut-throat flume was set up in the main sediment-meltwater channel of the largest retrogressive thaw slump on Herschel Island. In addition, two weather stations, one on top of the undisturbed tundra and one on the slump floor, measured incoming solar radiation, air temperature, wind speed and precipitation. The discharge volume eroding from the ice-rich permafrost and retreating snowbanks was measured and compared to the meteorological data collected in real time with a resolution of one minute. The results show that the release of sediment-meltwater from thawing of the ice-rich permafrost headwall is strongly related to snowmelt, incoming solar radiation and air temperature. Snowmelt led to seasonal differences, especially due to the additional contribution of water to the eroding sediment-meltwater from headwall ablation, lead to dilution of the sediment-meltwater composition. Incoming solar radiation and air temperature were the main drivers for diurnal and inter-diurnal fluctuations. In July (2013), the retrogressive thaw slump released about 25 000 m³ of sediment-meltwater, containing 225 kg dissolved organic carbon and 2050 t of sediment, which in turn included 33 t organic carbon, and 4 t total nitrogen. In August (2012), just 15 600 m³ of sediment-meltwater was released, since there was no additional contribution from snowmelt. However, even without the additional dilution, 281 kg dissolved organic carbon was released. The sediment concentration was twice as high as in July, with sediment contents of up to 457 g l-1 and 3058 t of sediment, including 53 t organic carbon and 5 t nitrogen, being released. In addition, the data from the 36 days of observations from Slump D were upscaled to cover the main summer season of 1 July to 31 August (62 days) and to include all 229 active retrogressive thaw slumps along the Yukon Coast. In total, all retrogressive thaw slumps along the Yukon Coast contribute a minimum of 1.4 Mio. m³ sediment-meltwater each thawing season, containing a minimum of 172 000 t sediment with 3119 t organic carbon, 327 t nitrogen and 17 t dissolved organic carbon. Therefore, in addition to the coastal erosion input to the Beaufort Sea, retrogressive thaw slumps additionally release 3 % of sediment and 8 % of organic carbon into the ocean. Finally, the future evolution of retrogressive thaw slumps under a warming scenario with summer air temperatures increasing by 2-3 °C by 2081-2100, would lead to an increase of 109-114% in release of sediment-meltwater. It can be concluded that retrogressive thaw slumps are sensitive to climatic conditions and under projected future Arctic warming will contribute larger amounts of thawed permafrost material (including organic carbon and nitrogen) into the environment

Es taut! Frozen-Ground Cartoons: Eine internationale Kooperation zwischen Künstlern und Permafrost-Wissenschaftlern

Dieses Projekt startete im Oktober 2015 mit einer verrückten Idee: Schreiben und Einreichen eines Antrags auf Förderung einer internationalen, multidisziplinären und nicht-traditionell wissenschaftlichen Projektinitiative… innerhalb von 48 Stunden. Und es hat geklappt ! Eine Gruppe hoch motivierter, junger Forscher aus Kanada und Europa hat sich gebildet, um Kunst und Wissenschaft zu kombinieren und eine Reihe von Comics über Permafrost (gefrorene Böden) zu produzieren. Unser Ziel ist es, zu zeigen, wie wissenschaftliches Arbeiten im hohen Norden funktioniert, mit dem Schwerpunkt auf Geländearbeit und den schnellen Umweltveränderungen in der Arktis. Die Zielgruppe sind Kinder, Jugendliche, Eltern und Lehrer, mit dem allgemeinen Ziel, Permafrost zugänglicher und mit Spaß zu vermitteln. Denn ratet mal: Permafrost ist ein Gebiet von mehr als 20 Millionen km2 auf der Nordhalbkugel – ein riesiges Gebiet. Durch die Klimaerwärmung taut der Permafrost und wird zu instabil, um Häuser, Straßen und Flughäfen zu tragen. Durch das Auftauen von gefrorenem Boden werden außerdem Pflanzen- und Tierhabitate zerstört, die Wasserqualität und Ökologie von Seen beeinflusst und auf Grund der Freisetzung von Kohlenstoff als Treibhausgas in die Atmosphäre wird der Klimawandel sogar verstärkt. Daher betrifft Permafrost und seine Reaktion auf den Klimawandel uns alle. Die Internationale Permafrost Gemeinschaft (IPA) hat das Projekt als „Action Group“ von Beginn an unterstützt und seitdem sind noch viele weitere Sponsoren dazugekommen. Und hier sind wir nun: Zwei Jahre nach der ersten Idee. Ihr seid kurz davor das zu lesen, was das Ergebnis eines ständigen Austauschs zwischen Künstlern und Wissenschaftlern ist. Zunächst hatten wir eine Ausschreibungsrunde und erhielten 49 Bewerbungen von Künstlern aus 16 Ländern. Durch ein Bewertungsverfahren wählten wir zwei Künstlerinnen aus, um an diesem Projekt zu arbeiten: Noémie Ross aus Kanada und Heta Nääs aus Finnland. Mit den Beiträgen von Wissenschaftlern erstellten Noémie und Heta fantastische Cartoons, die ein paar der Veränderungen erklären, die in Permafrost-Gebieten passieren. Zum Beispiel: wie wird die Welt der Menschen und Tiere beeinflusst und was machen Forscher, um diese Prozesse besser zu verstehen, sodass sie den Einheimischen helfen können, innovative Wege zur Anpassung zu finden

Frozen-Ground Cartoons: An international collaboration between artists and permafrost scientists

Communicating science about a phenomenon found under ground and defined by its thermal properties in an easy, funny, and engaging way, can be a challenge. Two years ago, a group of young researchers from Canada and Europe united to tackle this problem by combining arts and science to produce a series of outreach comic strips about permafrost (frozen ground). Because this concerns us all. As the climate warms, permafrost thaws and becomes unstable for houses, roads and airports. The thawing also disrupts ecosystems, impacts water quality, and releases greenhouse gases into the atmosphere, making climate change even stronger. The Frozen Ground Cartoon project aims to present and explain permafrost research, placing emphasis on field work and the rapidly changing northern environment. The target audience is kids, youth, parents and teachers, with the general goal of making permafrost science more fun and accessible to the public. The project has so far produced 22 pages of comics through an iterative process of exchanging ideas between two artists and thirteen scientists. The project artists were selected through an application call that received 49 applications from artists in 16 countries. With input from scientists, artists Noémie Ross (Canada) and Heta Nääs (Finland) have created a set of beautiful, artistic, humoristic, and pedagogic comics. The comics are available for free download through the project web page (in English and Swedish), and printed copies have so far been handed out to school kids and general public in Europe and Canada. The next steps of this project are (1) to distribute the comics as wide as possible, (2) work towards translations into more languages, and (3) to evaluate the effectiveness of the science communication through the comics, in collaboration with schools and pedagogic experts

Meteorology, hydrology, granulometry and chemistry of samples of different retrogressive thaw slumps at Herschel Island and the Yukon Coast, Yukon Territory, Canada, in 2012-2013

The Yukon Coast in Canada is an ice-rich permafrost coast and highly sensitive to changing environmental conditions. Retrogressive thaw slumps are a common thermoerosion feature along this coast, and develop through the thawing of exposed ice-rich permafrost on slopes and removal of accumulating debris. They contribute large amounts of sediment, including organic carbon and nitrogen, to the nearshore zone. The objective of this study was to 1) identify the climatic and geomorphological drivers of sediment-meltwater release, 2) quantify the amount of released meltwater, sediment, organic carbon and nitrogen, and 3) project the evolution of sediment-meltwater release of retrogressive thaw slumps in a changing future climate. The analysis is based on data collected over 18 days in July 2013 and 18 days in August 2012. A cut-throat flume was set up in the main sediment-meltwater channel of the largest retrogressive thaw slump on Herschel Island. In addition, two weather stations, one on top of the undisturbed tundra and one on the slump floor, measured incoming solar radiation, air temperature, wind speed and precipitation. The discharge volume eroding from the ice-rich permafrost and retreating snowbanks was measured and compared to the meteorological data collected in real time with a resolution of one minute. The results show that the release of sediment-meltwater from thawing of the ice-rich permafrost headwall is strongly related to snowmelt, incoming solar radiation and air temperature. Snowmelt led to seasonal differences, especially due to the additional contribution of water to the eroding sediment-meltwater from headwall ablation, lead to dilution of the sediment-meltwater composition. Incoming solar radiation and air temperature were the main drivers for diurnal and inter-diurnal fluctuations. In July (2013), the retrogressive thaw slump released about 25 000 m³ of sediment-meltwater, containing 225 kg dissolved organic carbon and 2050 t of sediment, which in turn included 33 t organic carbon, and 4 t total nitrogen. In August (2012), just 15 600 m³ of sediment-meltwater was released, since there was no additional contribution from snowmelt. However, even without the additional dilution, 281 kg dissolved organic carbon was released. The sediment concentration was twice as high as in July, with sediment contents of up to 457 g l-1 and 3058 t of sediment, including 53 t organic carbon and 5 t nitrogen, being released. In addition, the data from the 36 days of observations from Slump D were upscaled to cover the main summer season of 1 July to 31 August (62 days) and to include all 229 active retrogressive thaw slumps along the Yukon Coast. In total, all retrogressive thaw slumps along the Yukon Coast contribute a minimum of 1.4 Mio. m³ sediment-meltwater each thawing season, containing a minimum of 172 000 t sediment with 3119 t organic carbon, 327 t nitrogen and 17 t dissolved organic carbon. Therefore, in addition to the coastal erosion input to the Beaufort Sea, retrogressive thaw slumps additionally release 3 % of sediment and 8 % of organic carbon into the ocean. Finally, the future evolution of retrogressive thaw slumps under a warming scenario with summer air temperatures increasing by 2-3 °C by 2081-2100, would lead to an increase of 109-114% in release of sediment-meltwater. It can be concluded that retrogressive thaw slumps are sensitive to climatic conditions and under projected future Arctic warming will contribute larger amounts of thawed permafrost material (including organic carbon and nitrogen) into the environment. The tables show data for grain size, weather (discharge) and a sample list for different retrogressive thaw slumps on Herschel Island, Yukon, Canada