Permafrost is important for so many reasons – it's a natural carbon reservoir, the base for infrastructure, and a home to many species. Understanding how it's changing and the downstream effects of these changes is so important for making good decisions about all these things!

Greening trends appear associated with smaller seasonal subsidence, thinner active layers, and wetter soil:

Burned areas have higher soil water content than unburned areas:

Lower soil moisture (volumetric water content) is associated with deeper active layers, suggesting that Arctic soil may become drier as the climate warms:

This data set measures subsidence, soil moisture, and active layer thickness of #permafrost at millions of points. This allows us to investigate what processes and relationships from smaller-scale studies hold over larger regions. What do we discover? ⤵️

Would love to join this community! :)

Interested in joining too, thanks for organizing!

I hope you'll check our paper out if you have any interest in SAR, InSAR, or remote sensing of soil moisture or vegetation -- and please let me know if you have any questions 😊

We also show that systematic bias in the closure phase can be caused by asymmetries in the time series, where wetting and drying happen at different rates. A more asymmetric time series (wetting is much faster or slower than drying) tends to produce a more "biased" time series.

Estimation of soil moisture is poorer over crop land, likely because of changing vegetation. We characterize the accuracy of our estimate across different land cover types.

We show that cumulative InSAR closure phase can be used to estimate soil moisture at 37 sites, validating with in situ measurements in Oklahoma. The estimates can be quite accurate!

We use a model and real data to show that, because closure phase relates to *changes* in scattering properties, you can *cumulatively sum* a closure phase time series -- as a new way to measure soil moisture!

InSAR closure phase is the result of combining radar signals from satellite overpasses from 3 different times. It's particularly sensitive to changing scattering properties on the ground, such as changes in soil moisture.

…Or to come to watch me present, also tomorrow (Tues) 9:10-9:20 a.m., on what the results from the @ABoVE Permafrost Dynamics Observatory can tell us about the dynamic active layer soil moisture, and greening and browning