AON: Thermal State of Permafrost (TSP) in North America and Northern Eurasia: The US Contribution to the International network of Permafrost Observatories (INPO)

There exists no global database that defines the thermal state of permafrost within a specific time interval. Internationally, reported or unpublished temperature measurements have been obtained at various depths and periods over the past five or more decades, and it is known that these temperatures have changed at different rates in different regions. Analysis of temperature measurements obtained in these boreholes provides historical records of secular surface climate changes (deep holes) and interannual to decadal changes in surface boundary layer (intermediate depths). The Global Terrestrial Network for Permafrost (GTN-P) is a metadata based system established in the late 1990s under the World Meteorological Organization (WMO) which currently contains access to more than 425 documented borehole and 165 active layer sites across both polar regions. In Alaska, two major series of boreholes exist within the GTN-P with observations dating back to the 1970s; the US Geological Survey deep boreholes (>125 m) and the University of Alaska's intermediate boreholes (<100m). This effort will link approximately 80 Alaskan boreholes with sites of observations in other countries in Northern Eurasia, and in so doing will initiate the International Network of Permafrost Observatories (INPO). This work will coordinate data collection using standard equipment and protocols at the Alaskan borehole sites and at a selected number of sites in Russia. The Alaskan and Eurasian borehole temperature data sets will provide the baseline to reconstruct past surface temperatures, to assess the future rates of change in near-surface permafrost temperatures and permafrost boundaries, and to provide spatial data for validation of climate scenario models and temperature reanalysis approaches.