ARCSS Program | Co-oP Concept Paper Submissions By Author

Kenneth Hinkel

Response: Thaw Lakes and Basins in the Arctic Landscape

Response: Land Cover Change, Thermokarst, Arctic Lakes

Response: Lead: Kenneth M. Hinkel (University of Cincinnati)

Key Participants: Kim Peterson (University of Alaska Anchorage), Laurence Smith (University of California, Los Angeles); Chris Burn (Carleton University); Richard Beck (Central State University); Chris Cuomo, Wendy Eisner, Robert Frohn, Eric Maurer (University of Cincinnati); Frederick Nelson (University of Delaware); Craig Tweedie (University of Texas at El Paso); James Bockheim (University of Wisconsin, Madison); Dirk Derksen, Carl Markon, Benjamin Jones (USGS & SAIC, Anchorage)

Response: This project addresses four major scientific themes that include: assessing the current status of thaw lakes and basins; identifying processes associated with lake formation, expansion and drainage; integrating indigenous knowledge to enhance standard scientific methods; and estimating carbon pools in organic-rich reservoirs. The study area includes northern Alaska, northwestern Canada, and broad reaches of Siberia. Specifically:

(1) How many thaw lakes, ponds and associated drained thaw lake basins (DTLBs) exist? What are their areal extent and morphometric (shape, orientation) characteristics, and do these parameters change over space and across time scales ranging from the multi-decadal to the multi-millennial?

(2) What are the dominant structural and functional processes associated with thaw lake expansion, drainage and land cover change? How can we discriminate the effects of local processes from regional forcing? How are lake dynamics affected by local relief, regional elevation gradients, ground ice content, surficial materials, vegetation, landscape age, geomorphic history and human activity? How have lake dynamics and biota responded to climate change in the past, and how they might respond to climate amelioration?

(3) To what degree can we utilize indigenous knowledge (IK) to identify and verify mechanisms of lake expansion and drainage? Can oral histories be used to document changes in the landscape? What impact might widespread landscape change have on traditional cultures?

(4) How much soil organic carbon is currently sequestered in DTLBs and peatlands, and how susceptible is the carbon to mobilization given soil warming?

Response: Thaw lakes constitute a type of thermokarst terrain and represent the effect of permafrost thaw and ground subsidence at the surface. In landscapes where thaw lakes are the dominant geomorphic feature, lakes represent the quasi-equilibrium response to regional or global climate forcing that impacts the entire landscape. Lakes, in turn, alter the thermal regime of the underlying permafrost. As the ground thaws and subsides, lake basins deepen and expand. Following eventual drainage, DTLBs and peatlands are sites for preferential accumulation of soil organic carbon which has the potential to amplify warming if stored carbon becomes mobilized to the atmosphere as greenhouse gases. Owing to their prevalence, extent and properties, a deeper understanding of arctic lake and DTLB dynamics is required to assess the future state of the earth system.

Recent studies by members of this CoP have demonstrated that there has been an increase in the number of lakes by 4% and a concurrent increase in total lake area by 12% in the continuous permafrost zone of western Siberia over the period 1973 to 1997-1998. In contrast, the number of lakes and their areal coverage in northern Alaska has decreased since 1955. These seemingly contradictory results suggest that potential change may not be spatially uniform, or that rates of lake expansion may vary regionally. Assessing the arctic system trajectory into the future therefore entails understanding fundamental ecosystem processes that vary over time and space.

The direct and indirect impact of changing lake dynamics on indigenous societies, and the impact of human activities on lakes and their biota, are central to this project. Understanding the interconnected physical, biological and social systems are required to identify process hubs, drivers and linkages; this necessitates an inter- and multidisciplinary approach.

Response: Hydrologists, biologists, climate modelers, biogeochemists, social scientists, educators, local community leaders, IK groups.

Response: Less than 30, more than 10

Response: Less than 30, more than 10

Response: Landscape process modelers, field geomorphologists, climate modelers, social scientists, educators, limnologists, ecologists, IK community.

Response: Web Conferences
Scientifically focused Webseminars
Online Bulletin Board
Other

Response: Meeting support and coordination in conjunction with large national or international meetings, publication of popular science articles, and education and outreach materials.