Global Terrestrial Network for Permafrost Contributions to cryospheric and climate monitoring Sharon Smith Geological Survey of Canada Kananaskis, March

Embed Size (px)

DESCRIPTION

Permafrost is an important feature of the northern landscape Pingo Massive ice Patterned ground Permafrost affected peatlands

Citation preview

Global Terrestrial Network for Permafrost Contributions to cryospheric and climate monitoring Sharon Smith Geological Survey of Canada Kananaskis, March 2, 2005 variations in permafrost temperatures can be a sensitive indicator of climate change and variability warming and thawing of permafrost can have impacts on natural and human systems: Permafrost variations have implications for terrain stability, hydrology, gas fluxes, infrastructure, northern development and ecosystems. Permafrost is soil or rock that remains below 0C throughout the year Permafrost is an important component of the cryosphere and an integral part of the climate system Permafrost is an important feature of the northern landscape Pingo Massive ice Patterned ground Permafrost affected peatlands Presence of permafrost and ground ice presents challenges to northern development presence of permafrost and thaw settlement/frost heave considered in design of infrastructure techniques used to preserve infrastructure integrity Thawing of massive ice Techniques to preserve frozen ground Utilidors Foundation design for permafrost environments Warming and thawing of frozen ground can lead to instabilities in the landscape Unstable ground Active layer detachment Thawing of ground ice and thermokarst terrain Damage to buildings and infrastructure Global Climate Observing System (GCOS) and the Global Terrestrial Network for Permafrost (GTN-P) Key cryospheric variables for monitoring through WMOs GCOS Active layer Permafrost thermal state GTN-P established under leadership of International Permafrost Association (IPA) in 1999 Provide long-term observations of active layer and permafrost temperature that are required for: understanding the present permafrost conditions detection of terrestrial climate signal in permafrost and its temporal and spatial/regional variability development and validation of permafrost, climate change and impact models assessment of carbon sources and sinks in permafrost regions northern development and land use decisions design of adaptation strategies to mitigate the impacts of climate warming in permafrost improving our ability to provide ongoing, large area, timely assessment of cryospheric change GTN-P web site gtnp.org GTN-P Thermal monitoring sites Circumpolar Active Layer Monitoring (CALM) Network 125 sites contribute to CALM Active layer thickness determined through probing thaw tubes temperature measurements Measurements maybe done at points along transects on grids Thaw depth determined from interpolation of ground temperature profile at Baker Lake BH4 Active layer, Mackenzie Delta Thaw depth Ground surface Measurement of thaw settlement Permafrost Thermal State Borehole monitoring few metres to several 100 m deep frequency of measurements varies from daily to monthly to annual to several years Method Single probe Permanent multi-sensor cable manual measurements continuous measurements with data loggers Alert 15 m Trend C/yr High frequency data collection with data loggers Alert BH5 Manual Measurements Alert BH5 Temperature Envelopes - Alert Collection of Climate Data Alert Thaw depth Ground surface Iqaluit - Monthly ground temperatures at 5 m depth Peatland site Northern AlbertaGround surface temperature Mackenzie Delta region Evaluation of impact of warming Analysis of trends in air and permafrost tempeature Determination of onset of freezing and thawing Model validation High Arctic Observatories Hydrocarbon Wells Deep temperature measurements using single probe High frequency temperature measurement to depths of 80 m since 1991 Data used to determine ground surface temperature history Data retrieval from Gemini near Eureka Data retrieval from Pat Bay, Lougheed Island Challenges of Arctic field work High Arctic Observatories High resolution data collection Development of ground surface temperature histories through application of mathematical inversion techniques 20.75m 30.75m 65.75m 47.75m 25.75m 35.75m Mean annual permafrost temperature from Pat Bay, Lougheed Island Mean annual permafrost temperature from Gemini, near Eureka Reconstruction of Ground Surface Temperature History Inversion of deep logs for hydrocarbon wells (Pat Bay and Gemini) + inversion of shallow temperature logs ( ) Gemini GSTH Comparison of Gemini and Pat Bay GSTH Comparison of inversion of 800 m log with inversion of 800 m log and 8 one year means for Gemini Alert Ground Surface Temperature History Reconstruction GSTH determined from shallow (to 60m) temperature logs Simultaneous inversion of 9 one year means ( ) Development of Remote Sensing Techniques Remote sensing techniques can potentially extend the in situ measurements from GTN-P to the broader spatial domain GTN-P can provide data for development and validation of remote sensing techniques Information provided through remote sensing can complement the in situ measurements and lead to for example quantification of freeze-thaw states quantification of carbon budgets improved climate change impact assessments Summary GTN-P provides information that can be used to: Document and quantify fluctuation in permafrost conditions Improve understanding of cryosphere-climate processes Develop and validate permafrost-climate models Including improved representation of ground thermal regime in climate models Development and validation of remote sensing techniques Permafrost temperature trends, Mackenzie Valley, south of Norman Wells