Exploring our water planet

Although the global heat and water fluxes over land are important, like those over the ocean, they have not been well investigated due to the difficulties in obtaining wide-area information of precipitation and land surface water reservoirs such as soil moisture and snow. AMSR's lower frequency channels have better sensitivity to the soil moisture than before. In addition, these channels are also effective for snow observation in improving accuracy in heavy snowfall regions and in classifying snow types. By utilizing these characteristics, we will endeavor to quantitatively observe global land parameters related to water.

The amount of soil moisture affects evaporation efficiency from land surfaces and controls heat and water fluxes into the atmosphere. Snow cover itself affects the radiation budget by reflecting solar light back to space. In addition to this albedo effect, snow melting provides soil moisture and influences surface fluxes in the summertime. Seasonal melting of permafrost distributed over the Eurasian Continent and the Tibetan Plateau also serves as a supply source of soil moisture as well as the seasonal change of soil depth where soil moisture can be stored. Similar to snow cover, frozen soil seals in the soil moisture information of the previous year. Melting in the next year functions as a memory of the information and modulates the seasonal variation of atmospheric circulation.

| Exploring our water planet |