The water exchange between the land, ocean and atmosphere is one of the most important factors determining weather and climate. Due to the close relationship between the water cycle and the climate, the accuracy of regional and global climate predictions is strongly dependent on the uncertainties in the dynamics of the water cycle.
In climate models, soil moisture is a core parameter for characterising the land surface, because it directly influences the heat and water transport between the land surface and the atmosphere. Even small variations in the water content have a large influence on the thermal characteristics of the land. Due to the strong temporal and spatial variability, measurement of soil moisture and its dynamics is practically impossible.
Today, we can observe changes in the water cycle, such as the accelerated melting of snow, ice and glaciers or the increased rain and reduced snowfall due to the raise of temperatures. Often, positive feedback can occur, e.g., less snow and longer melting periods can lead to an additional increase in the temperature.
For the first time, Tandem-L will record the critical components of the water cycle, such as soil moisture, and the dynamics of flow and melting processes in the cryosphere on a global scale with high temporal and spatial resolution.