Schaefer, Kevin: National Snow and Ice Data Center (Project Lead)
Moghaddam, Mahta: University of Southern California (Co-Investigator)
Parsekian, Andrew (Andy): University Of Wyoming (Co-Investigator)
Thompson, Jeffery: University of Colorado (Co-Investigator)
Zebker, Howard: Stanford University (Co-Investigator)
Michaelides, Roger: Washington University in St. Louis (Participant)
Huang, Lingcao: University of Colorado Boulder (Post-Doc)
Sullivan, Taylor: University of Wyoming (Student-Graduate)
Wig, Elizabeth: Stanford University (Student-Graduate)
Zhao, Yuhuan: University of Southern California (Student-Graduate)
Clayton, Leah: Yale University (Student-Undergraduate)
Westenhoff, John: University of Wyoming (Student-Undergraduate)
Project Funding:
2016 - 2019
NRA: 2016 NASA: Terrestrial Ecology
Funded by NASA
Abstract:
The Airborne Interferometric and Polarimetric Synthetic Aperture Radar Permafrost Dynamics Observatory (PDO) will combine data from the AirMOSS and UAVSAR instruments to simultaneously measure seasonal subsidence, Active Layer Thickness (ALT) and soil moisture. The PDO combines proven techniques to measure ALT and soil moisture: Remotely Sensed Active Layer Thickness (ReSALT) and the polarimetric retrieval from AirMOSS. ReSALT uses the Interferometric Synthetic Aperture Radar (InSAR) technique to measure ALT and the polarimetric retrieval uses backscatter observations to measure soil moisture and ALT. PDO will use backscatter measurements from both the P-band AirMOSS and L-band UAVSAR instruments to measure soil moisture. PDO will apply the InSAR technique to both P-band and L-band data to measure surface subsidence and ALT.
The combined PDO retrieval will measure seasonal subsidence, ALT and soil moisture using four distinct observations from two instruments at two frequencies. The team will use Ground Penetrating Radar to collect in situ measurements of ALT and soil moisture along the ABoVE flight path to validate the PDO retrieval. The team will perform several statistical analyses between PDO data and data from other foundation instruments to quantify statistical relationships between vegetation conditions, ALT, and soil moisture that cut across spatial scales. These include scaling PDO ALT up to the entire permafrost domain and scaling SMAP data down to the 10-meter resolution of the flight data.
PDO is the first to combine InSAR and polarimetric backscatter observations from two instruments at two frequencies, resulting in a retrieval that is much more powerful than the individual techniques alone. The PDO project makes maximum use of ABoVE airborne data by using all of the UAVSAR and AirMOSS data and a large portion of data from the remaining foundational instruments. The PDO products will complement currently funded ABoVE science projects, many of which have already requested ReSALT and AirMOSS data for their study areas. PDO directly addresses three of the six ABoVE science questions and will remotely sense five of the twenty high priority parameters.
Permafrost influences all other hydrological, ecological, and disturbance processes, making the PDO data and statistical analyses applicable to ABoVE science questions. The PDO techniques readily transfer to the planned NASA-ISRO Synthetic Aperture Radar (NISAR) mission and fulfill its requirement to study permafrost dynamics. The PDO provides validation data for SMAP and a simpler, data-driven technique to downscale SMAP data. PDO represents a bridge in spatial scales necessary for the development of a successful satellite product: in situ ALT measurements linked with intermediate spatial scales from airborne measurements flowing up to global satellite measurements.
The team is uniquely qualified to meet PDO objectives. The University of Colorado and Stanford teams jointly developed the ReSALT retrieval of ALT. The University of California team developed the polarimetric retrieval and served as PI on the original AirMOSS project. The University of Wyoming team has used GPR to measure ALT and soil moisture across the Arctic.
Publications:
Chen, R. H., Michaelides, R. J., Zhao, Y., Huang, L., Wig, E., Sullivan, T. D., Parsekian, A. D., Zebker, H. A., Moghaddam, M., Schaefer, K. M. 2022. Permafrost Dynamics Observatory (PDO) - Part II: Joint Retrieval of Permafrost Active Layer Thickness and Soil Moisture from L-band InSAR and P-band PolSAR. Earth and Space Science. DOI: 10.1029/2022EA002453
Michaelides, R. J., Schaefer, K., Zebker, H. A., Parsekian, A., Liu, L., Chen, J., Natali, S., Ludwig, S., Schaefer, S. R. 2019. Inference of the impact of wildfire on permafrost and active layer thickness in a discontinuous permafrost region using the remotely sensed active layer thickness (ReSALT) algorithm. Environmental Research Letters. 14(3), 035007. DOI: 10.1088/1748-9326/aaf932
Schuster, P. F., Schaefer, K. M., Aiken, G. R., Antweiler, R. C., Dewild, J. F., Gryziec, J. D., Gusmeroli, A., Hugelius, G., Jafarov, E., Krabbenhoft, D. P., Liu, L., Herman-Mercer, N., Mu, C., Roth, D. A., Schaefer, T., Striegl, R. G., Wickland, K. P., Zhang, T. 2018. Permafrost Stores a Globally Significant Amount of Mercury. Geophysical Research Letters. 45(3), 1463-1471. DOI: 10.1002/2017GL075571
Yumashev, D., Hope, C., Schaefer, K., Riemann-Campe, K., Iglesias-Suarez, F., Jafarov, E., Burke, E. J., Young, P. J., Elshorbany, Y., Whiteman, G. 2019. Climate policy implications of nonlinear decline of Arctic land permafrost and other cryosphere elements. Nature Communications. 10(1). DOI: 10.1038/s41467-019-09863-x
More details may be found in the following project profile(s):
