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SoilSCAPE Sensor Network in Alaska: Studying Permafrost Active Layer Dynamics in the Arctic
Richard
Chen, University of Southern California, chenrh@usc.edu
Agnelo
Silva, Decagon Devices, Inc., agnelors@gmail.com
Kazem
Bakian Dogaheh, University of Southern California, bakiando@usc.edu
Alireza
Tabatabaeenejad, University of Southern California, alirezat@usc.edu
Mahta
Moghaddam, University of Southern California, mahta@usc.edu
(Presenter)
The Soil moisture Sensing Controller And oPtimcal Estimator (SoilSCAPE) is an ultra-low-power wireless sensor network technology, developed under NASA/ESTO Advanced Information Science Technology (AIST) support, for measurement of soil properties including soil moisture and temperature profiles. The SoilSCAPE network technology, initially developed to support calibration and validation activities of NASA missions such as SMAP and AirMOSS, has been enhanced in several ways to allow its operation in the arctic environment in support of ABoVE. The redesign included various power management and environmental robustness considerations for operating the network in the harsh cold and dark arctic environment, as well as redesigning the hardware and software communications interfaces to seamlessly integrate with satellite (Iridium) links. Data compression schemes and dynamic scheduling were also implemented to optimize cost vs. science information content of the data delivered to our gateway at USC. Two separate networks were installed in the Alaska North Slope with a total of 13 network nodes.
These new SoilSCAPE-arctic networks in Happy Valley and Prudhoe Meadow have been delivering near-real-time high-quality in-situ field data, including dielectric constant, electrical conductivity, and temperature throughout the permafrost active layer soil profile. With the novel power management and robust environmental design strategies that we have now tested under a number of dynamic environmental conditions, we expect to achieve sustained unattended network operation for 1- 2 years.
What we have learned from the data has been unique: For example, our data have directly shown that the permafrost active layer freeze-thaw transition involves much more than a temperature transition, and that instead it is marked very strongly by a transition in the dielectric constant and conductivity of the soils. During the extended zero-curtain period of time in the Fall, even though the temperatures hover around zero-C, the soil still keeps a relatively high dielectric constant and conductivity. We have shown that the final transition to frozen state is indicated by a sharp switch in dielectric constant and conductivity. The SoilSCAPE-arctic data are also being used directly for validation of radar-derived retrievals of active layer thickness and soil moisture. The data are shedding light on the soil profile spatial and temporal dynamics that are essential not only for accurate formulation of radar retrieval models, but also for parameterizing recently developed process models for characterizing distributions and dynamics of the active layer.
Associated Project(s):
Poster Location ID: 28
Session Assigned: Permafrost and Hydrology
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