Home News SMOS satellite detects freezing soil

SMOS satellite detects freezing soil

Paris, France: European Space Agency’s (ESA) Soil Moisture and Ocean Salinity (SMOS) satellite is designed to observe soil moisture and ocean salinity, but this innovative mission is showing that it can also offer new insight into Earth’s carbon and methane cycles by mapping soil as it freezes and thaws, the ESA claimed. While SMOS provides essential information for understanding the water cycle, weather and climate system, scientists from the Finnish Meteorological Institute have recently developed a method of using the data to detect and map frozen soils. Not only can the extent be mapped, but also the depth of the frozen layer can be inferred.
Moreover, there is great concern that rising global temperatures will cause permanently frozen soil, permafrost, in high latitudes to thaw – releasing massive volumes of carbon and methane and adding further to the greenhouse effect. 
Dr Kimmo Rautiainen from the Finnish Meteorological Institute (FMI) said, “Detecting frozen soils and the depth to which they are frozen from space has been an unresolved scientific problem. However, we are now confident that the novel observations provided by the SMOS mission will help advance our understanding of processes occurring in cold regions.”
During the freezing process, brightness temperatures increase until the top 50 cm of the soil is frozen. Over winter the readings remain stable, even under the presence of deep snow. Thawing in spring then leads to a decrease in brightness temperature.  The SMOS data have been validated by observations taken from a ground-based radiometer at FMI’s Arctic Research Centre in Sodankylä, northern Finland. It is envisaged that similar data will be produced and released for use in applications such as numerical weather prediction and hydrology. 
Source: ESA