ADEOS-II/AMSR L2 Water Vapor dataset is obtained from the AMSR sensor onboard ADEOS-II and produced by the Japan Aerospace Exploration Agency (JAXA).The Advanced Earth Observing Satellite-II (ADEOS-II) was launched on December 14, 2002 (Japanese Standard Time). The objective of ADEOS-II was to acquire data to contribute to international global climate change research, as well as for applications such as meteorology and fishery. ADEOS-II operation on orbit was given up on October 31 2003, because sufficient electric power was not available to maintain operation of the satellite.AMSR observes various physical contents concerning to water (H2O) by receiving weak microwaves naturally radiated from the Earth's surface and atmosphere and also regardless of day or night, the presence of clouds. Those sensors aim at collecting global data for mainly understanding the circulation of water and energy.Level 2 product stores the Geophysical quantity from the brightness temperature of level 1 product. This product includes Water Vapor (WV). PWI (water vapor index) is converted to total water vapor content (PWA, kg/m^2) using a look-up table, which is designed as the provability of PWA with AMSR retrievals is equivalent to that of PWA with radio sonde. If PWI is out of range of look-up table, the flag 'low accuracy' is added. The physical quantity unit is kg/m^2.The provided format is HDF4. Spatial resolution is 10 km. The current version of the product is "Version 7". The generation unit is scene (defined as a half orbit).