About Satellite Soil Moisture Maps

Satellite soil moisture maps are produced using remotely sensed data from the European Space Agency's Soil Moisture Ocean Salinity (SMOS) satellite mission. In this mission, satellites are used to sense the strength of radiation emitted from the surface of the earth. There is a strong difference in the signals emitted by dry soil and wet soil. This relationship is used to calculate surface soil moisture using a model that incorporates land cover, vegetation content, surface roughness, soil texture and other factors that influence the satellite sensor. The satellite collects data every one to three days over Canada. To learn more about the mission, visit the Soil Moisture Ocean Salinity website.

Difference from average soil moisture is calculated by comparing current conditions data to the average in the data collected since the SMOS satellite launch in 2009. In the maps, areas covered by snow, frozen ground, dense vegetation, or areas with high elevation appear white and are removed from the data. Signals that interfere with producing an accurate picture of surface soil moisture conditions are also removed.

Agriculture and Agri-Food Canada's soil moisture map products are produced on a weekly, bi-weekly and monthly basis for all of Canada. These products are used for many purposes, including risk assessment, emergency monitoring, estimating food production and flood prediction. Work is underway to integrate data from other satellites, including the NASA Soil Moisture Active Passive (SMAP) mission, which was launched in 2015.

For more information on the calculation of soil moisture, please refer to the SMOS Soil Moisture Retrieval Algorithm.

For an evaluation of this data as an indicator of drought and excess moisture, please see Monitoring Agricultural Risk in Canada Using L-Band Passive Microwave Soil Moisture from Soil Moisture Ocean Salinity.

To access in-situ soil moisture data, please refer to the Real‐Time In‐Situ Soil Monitoring For Agriculture (RISMA) Network.

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