Augmentation of the USArray sites with temperature profilers
Main Contact: Dr. Dmitry Nicolsky
Scientific Personel: Drs. Dmitry Nicolsky, Vladimir Romanovsky, Alexander Kholodov
Partner Organizations: Arctic-Boreal Vulnerability Experiment, NASA
NASA funded project
The ground temperature variability across the Arctic landscape depends on the air temperature, snow cover, moisture content, vegetation, terrain, soil properties and related environmental variables. A juxtaposition of all these factors results in a highly heterogeneous distribution of the ground temperature, active layer thickness and permafrost conditions. As a result, prediction of subsurface temperature dynamics remains challenging and mean temperatures for a study region may not account for "hot spots" of change, which alone could significantly contribute to thaw and associated carbon emissions. A solution is to sample (record) temperature regimes within different ecotypes and environment conditions, and build a portfolio of subsurface thermal regimes across various ground conditions. The proposed ground temperature profilers will supplement the existing data loggers and provide means to sample the ground temperature regime in currently underrepresented ecotypes to increase our knowledge of permafrost variability across Alaska and Northern Canada, Figure 1.
Figure 1. USArray sites in Alaska and Canada to be augmented with borehole temperature probes.
Starting in 2015, NASA's Terrestrial Ecology Program has been conducting the Arctic-Boreal Vulnerability Experiment (ABoVE), which is focused on a large-scale study of environmental change, including warming and thawing of permafrost soils leading to decomposition of long-frozen organic matter. Thawing and freezing of ground material is affected by many factors, with air temperature, vegetation, thermal properties of the ground material, snow accumulation, and soil moisture among the most significant. The range of spatial and temporal variability in these variables determines the extent and properties of permafrost, which is highly variable across the ABoVE domain. Permafrost temperature and ground properties determine how vulnerable the permafrost is to thaw, thus the rate at which degradation is occurring and will occur in future, as well as the carbon biogeochemistry and hydrology changes that will ensue. This is a central part of ABoVE’s overarching science question, which is “How vulnerable or resilient are ecosystems and society to environmental change in the arctic and boreal region of western North America?” It also addresses the first of ABoVE’s science objectives, which is “Determine how interactions among vegetation, hydrology & disturbances mediate permafrost vulnerability and resilience to climate change.
We thank the efforts of EarthScope and USAray personnel to establish the seismic monitoring sites in Alaska. We thank NASA ABoVE for the grant funding this project.
“How vulnerable or resilient are ecosystems and society to environmental change in the arctic and boreal region of western North America?”
To measure active layer and permafrost temperature distribution and dynamics across the ABoVE domain.
The opportunity provided by US Array is unique in allowing ABoVE to address the undersampling issue and inform a wide range of ABoVE research activities, particularly;
(i) scaling site measurements to landscapes in conjunction with remote sensing observations and products,
(ii) calibrating and validating remote sensing algorithms to map the extent and properties of permafrost landscapes, and
(iii) initializing, informing and assessing a range of ecosystem and earth system models that simulate permafrost dynamics and associated carbon fluxes.
USArray sites in Alaska and western Canada equiped with borehole temperature sensors at various depths below surface.
Table 1. List of Sites, Metadata and Reconnaissance Reports. (See file attachment below for more information.)
Permafrost temperature (degrees C) at depths (meters) at USArray equiped sites in Alaska and Canada (ABoVE NASA domain).
Table of Temperature Measurements (In Progress).
IRIS Alaska TA: Capabilities and Interdisciplinary Instrumentation: American Geophysical Union, Fall Meeting 2017, New Orleans, LA, Thursday 14 December, 03:30 to 5:00 pm, "Augmentation of USArray Sites with Temperature Profilers" (ppt below).
Geophysical Institute Permafrost Laboratory University of Alaska Fairbanks (future repository)
USArray Sites Detailed Field-Descriptions and Images on Google Drive (use google account for access):
USArray Metadata for Alaska-Canada Sites: