Soil Moisture Active/Passive Validation Experiment Within the Canadian Boreal Forest in 2022 (SMAPVEX22-Boreal)

The soil moisture active passive (SMAP) validation experiment in the boreal forest took place near Candle Lake, Saskatchewan within an area previously studied as a part of the experiments conducted at the Boreal Ecosystem Research and Monitoring Sites (BERMS). This study specifically focuses on the data collected within a single SMAP radiometer footprint, covering an area of approximately 30 × 30 km² within a boreal forest environment. The land cover 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 16–30 June and 6–18 August 2022. Numerous datasets were collected from sampling campaigns and through the installation of in situ networks. Comparisons among observed soil moisture (SM) and those retrieved from the SMAP and soil moisture and ocean salinity mission satellite platforms show a significant correlation to SM collected in situ. It is anticipated that the data collected as a part of this experiment (vegetation biomass and soil and vegetation structures) will be important for modeling efforts to improve SM retrievals in these environments.