GCOM-W/AMSR2 L2 Integrated Water Vapor dataset is obtained from the AMSR2 sensor onboard GCOM-W and produced by the Japan Aerospace Exploration Agency (JAXA). GCOM-W was launched by the H-IIA Launch Vehicle No. 21 (H-IIA F21) at 1:39 a.m. on May 18th, 2012 (Japan Standard Time, JST) and inserted into a planned position on the "A-Train" orbit. GCOM-W equipped with AMSR2 takes measurements at multiple microwave frequencies and multiple polarizations of weak electromagnetic waves in the microwave band radiated from the Earthâs surface and the atmosphere. AMSR2 has swath of 1450 km and 7 microwave bands. The observation data will enable the creation of long-term trustworthy data sets of global physical amount. Level 2 products calculates various geophysical parameters related to water using the Level 1B or 1R products as inputs. This dataset includes Integrated Water Vapor (WV), amount of vertically accumulated water vapor (H2O in gaseous state) in the atmosphere, and defined as amount of water per unit area. Coverage of the product is over the ocean only, and unit is [kg/m2]. Total precipitable water is one of essential hydrological parameters describing state of the atmosphere along with precipitation and cloud liquid water. The Pixel_Data_Quality is quality flag stored for each observation point. The provided format is HDF5. The Sampling resolution is 15 km. The current version of the product is Version 2. The Version 1 is also available. The generation unit is scene (defined as a half orbit).