Arctic Field Projects



Project Title: Dynamics and Consequences of Increasing Ice-wedge Degradation (Award# 1023623)

PI: Shur, Yuri L (yshur@alaska.edu)
Phone: (907) 474.7067 
Institute/Department: U of Alaska, Fairbanks, Civil and Environmental Engineering 
IPY Project?
Funding Agency: US\Federal\NSF\GEO\OPP\ARC\ARCSS
Program Manager: Dr. Neil Swanberg (nswanber@nsf.gov)
Discipline(s): | Cryosphere\Arctic Ecology | Cryosphere\Climate Change | Cryosphere\Permafrost |

Project Web Site(s):
NSF_Award_Info: http://www.nsf.gov/awardsearch/showAward.do?AwardN...

Science Summary:
This research will quantify the nature and extent of ice-wedge degradation, evaluate the feedbacks controlling the dynamics of degradation and stabilization, and assess the consequences of the degradation to arctic ecosystems. Massive ice in the form of ice wedges occupies 10-70% of near- surface permafrost and fundamentally influences the dynamics and vulnerability of arctic ecosystems to climate change, and this ice has been shown to be degrading. The dynamics of ice-wedge degradation have been shown to be affected by the positive feedback of impounded surface water and negative feedbacks from rapid vegetation and peat accumulation that are able to stabilize degrading ice wedges, yet there has been no quantification of the physical mechanisms controlling the processes. This degradation of ice wedges greatly affects arctic ecosystems by altering surface topography, modifying drainage networks, enhancing peat accumulation and methane production under anaerobic conditions, and radically shifting vegetation composition, but these consequences are poorly understood. Given that ice-wedge degradation directly or indirectly affects most arctic terrain it is critical to quantify the dynamics and consequences of ice-wedge degradation. This project addresses these uncertainties through a comprehensive assessment of the nature and extent of ice-wedge degradation, the feedbacks controlling ice-wedge dynamics, and the consequences of degradation on ecosystem patterns and processes. The research brings together an interdisciplinary team with expertise in permafrost and soil, biogeochemisty and trace gas emissions, vegetation, and remote sensing to address hypotheses through field surveys, remote sensing, and modeling. The extent and rate of ice-wedge degradation across landscapes and climates will be assessed by comparing the ice-wedge volume by terrain units, describing stages of degradation and stabilization; quantifying degradation across the circumarctic; developing image processing algorithms for mapping thermokarst; and quantifying degradation rates through aerial photo analysis. How the dynamics of ice- wedge degradation and stabilization are controlled by positive and negative feedbacks will be assessed by identifying structural properties of surface soils that protect ice wedges; quantifying differences in net radiation and soil heat flux among degradation stages; and identifying thresholds for thermokarst through numerical modeling. The consequences of ice-wedge degradation will be documented by quantifying micro-topographic changes caused by ice-wedge degradation; changes in surface water storage and drainage patterns; soil-organic carbon stocks through degradation sequence; differences in methane emissions among degradation stages; and quantifying shifts in vegetation composition through degradation sequence. The research is essential for understanding the effects of climate changes on permafrost and arctic ecosystems because ice wedges are an especially sensitive component of terrestrial arctic ecosystems. Better understanding of the nature and extent of ice wedges will improve land management, impact assessment, and facility design in ice-rich permafrost terrain. Information on the dynamics and feedbacks involved in ice-wedge degradation will help minimize effects of disturbance and to improve global climate change models that currently lack critical feedbacks. Documenting the consequences of degradation will help us better study the role of fragmenting drainage networks in assessments of circumarctic hydrology, help resolve whether arctic soils will gain or lose carbon in the future, contribute information for assessing methane emissions across dynamically changing ecosystems, and provide data on the rates of vegetation change which can affect satellite measurement of vegetation productivity during assessments of vegetation greening in the Arctic.

Logistics Summary:
This research integrates field sampling, remote sensing, and modeling to evaluate the nature and extent, dynamics, and consequences of ice-wedge degradation in Arctic ecosystems. During two years of field work, in 2011 - 2012, researchers will work at eight total sites in northern and central Alaska that cross a regional temperature gradient: along the Beaufort coastal plain (including Barrow, Alaska); Cape Espenberg on the Seward Peninsula; along the Dalton Highway; and in the interior of Alaska (Fairbanks area). The PI will lead sampling activities for site-specific and/or regional parameters. Researchers will fly on air charters to access sites within the Arctic National Wildlife Refuge, as well as at Cape Espenberg. They will use a Fairbanks-based truck to access sites near Fairbanks and along the Haul Road, including Deadhorse. In addition to this work, researchers will use point sampling of high-resolution Quickbird imagery for regional-scale analysis of remote measurements across Russia and Alaska. In 2012, research teams of varying sizes will conduct field work around the state, beginning in mid-May and continuing on and off through early August. They will use trucks, air support, and boats to access their field sites, either camping or staying in lodging as available. In May, CPS PM Cody Johnson will join the team for a sampling trip up the Dalton Highway.

CPS will provide air support and vehicles, and support in Barrow to include the following: user / truck days and permitting assistance. The PI will arrange/pay for all other logistics, including support for work in Russia.
SeasonField SiteDate InDate Out#People
2011Alaska - Fairbanks05 / 24 / 2011 09 / 25 / 20113
2011Alaska - Itkillik River08 / 10 / 2011 08 / 20 / 20114
2011Alaska - Jago07 / 29 / 2011 08 / 04 / 20112
2011Alaska - Prudhoe Bay06 / 07 / 2011 06 / 16 / 20114
2012Alaska - Itkillik River05 / 09 / 2012 05 / 15 / 20127
2012Alaska - Prudhoe Bay06 / 10 / 2012 08 / 31 / 20129
2012Alaska - Utqiaġvik (Barrow)07 / 28 / 2012 08 / 03 / 20125
 


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