Soil moisture active passive soil moisture validation experiment withing the Canadian Boreal Forest in 2022 (SMAPVEX22-Boreal)

Authors: BERG, A - University Of Guelph; WICKS, K - University Of Guelph; THOMAS, J - University Of Guelph; ROY, A - University Of Guelph; MAGAGI, R - Universite De Sherbrooke; HELGASON, W - University Of Saskatchewan; COLLIANDER, A - Jet Propulsion Laboratory; Cosh, Michael; TETLOCK, E - Environment Canada; GORRAB, A - University Of Quebec; ROY, C - University Of Quebec; SALMABADI, H - University Of Quebec; AMINI, Y - Carleton University - Canada

Submitted to: IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/9/2025
Publication Date: 5/5/2025
Citation: Berg, A., Wicks, K., Thomas, J., Roy, A., Magagi, R., Helgason, W., Colliander, A., Cosh, M.H., Tetlock, E., Gorrab, A., Roy, C., Salmabadi, H., Amini, Y. 2025. Soil Moisture Active Passive Soil Moisture Validation Experiment withing the Canadian Boreal Forest in 2022 (SMAPVEX22-Boreal). IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing. 18:11816-11834. https://doi.org/10.1109/JSTARS.2025.3564195.
DOI: https://doi.org/10.1109/JSTARS.2025.3564195

Interpretive Summary: Boreal forests are an important domain for monitoring climate impacts and soil moisture is a primary driver of ecosystem activity. Being able to estimate soil moisture over this kind of domain would improve our understanding of this vital region and inform models and predictions for climate change. An experiment was conducted in the summer of 2022 to capture data for algorithm development of a microwave radar signal over a boreal region of Saskatchewan. The results of the experiment showed that there is a lot of information in the satellite and aircraft signals, but future work is needed to understand how the diversity of the land surface and forest canopy impacts the signal.

Technical Abstract: The Soil Moisture Active Passive Validation Experiment in the Boreal forest (SMAPVEX22 boreal) took place near Candle Lake, Saskatchewan within an area previously studied as part of the experiments conducted as the Boreal Ecosystem Research and Monitoring sites (BERMS). This study specifically focuses on data collected within a single SMAP radiometer footprint, covering an area of approximately 30 x 30 km2 within a boreal forest environment. The landcover classes and soil types in the boreal forest area of the BERMS region are dominated by coniferous trees and soils represented by an often-thick, organic-rich layer of moss and leaf litter above a mineral soil layer. The completed field experiment focused on accurately representing both soils and vegetation of the region based on comprehensive sampling campaigns completed over two sampling periods between June 16-30 and August 6-18, 2022. Numerous datasets were collected via sampling campaigns and through the installation of in situ networks. Comparisons among observed soil moisture (SM) and those retrieved from the Soil Moisture Active Passive and Soil Moisture (SMAP) and Ocean Salinity Mission satellite (SMOS) platforms show significant correlation to SM collected in situ. It is anticipated that the data collected as part of this experiment (vegetation biomass, soil structure) will be important for modelling efforts to improve SM retrievals in these environments.