Aqua/AMSR-E L3 Water Vapor (1-Day, 0.25 deg)

It conically scans and keeps an angle of incidence on the earth surface (a nominal of 55 degrees) and accomplishes a swath width of about 1450 km. The AMSR-E reached its limit to maintain the antenna rotation speed necessary for regular observations, and the AMSR-E restarted its observation in slow rotation mode (2 rotations per minute) on December 4, 2012. However, the AMSR-E reached its limit to maintain the antenna rotation speed necessary for slow rotation mode and it automatically halted its observation and rotation on December 4, 2015.

Level 3 data inputs level 1B and level 2 data and projected to the map in accordance with the specified projection technique (Equi-Rectangular (EQR) or Polar Stereographic (PS)), and then the arithmetic average of 1 day is computed on each grid. Moreover, level 3 data for 1 day of each geophysical parameter is inputted for 1 month, arithmetic average of 1 month is computed on each grid, as the same way as 1 day average calculation.

This product includes daily mean 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. The physical quantity unit is kg/m^2.

The provided format is HDF4. The statistical period is 1 day. The spatial resolution is 0.25 deg.

The current version of the product is "Version 7". The projection method is EQR. The generation unit is global.