Water held in soil plays an important role in the climate system. The dataset released by ESA is the first remote-sensing soil moisture data record spanning the period 1978 to 2010 – a predecessor of the data now being provided by ESA's SMOS mission.
The datasets are now available to the science community for feedback analyses and climate model validation.
The amount of water held in global soils makes up only about 0.001% of the total water found on Earth.