Aqua/AMSR-E L2 AMSR2 Format Sea Surface Wind

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 2 product stores the Geophysical quantity from the brightness temperature of level 1 product.This product includes Sea Surface Wind (SSW). SSW is retrieved mainly from 36.5 GHz vertical (V) and horizontal (H) brightness temperature of AMSR by a graphical method.

The retrieval is restricted to no rain condition since the brightness temperature of 36.5 GHz is saturated under rainy condition, SSW obtained only from 36.5 GHz has a large anisotropic feature depending on an angle between antenna direction and wind direction. Its anisotropic feature is corrected by using two data from 36.5 and 10.65 GHz, since 10.65 GHz data are less anisotropic. Even under rainy condition, 10.65 and 6.925 GHZ data are not saturated, so wind speed is retrieved by using those H data.

Retrieval accuracy of wind speed using 10.65 and 6.925 GHz becomes worse than using 36.5 GHz, since a sensitivity of 10.65 and 6.925 GHz to wind speed is not so strong. 36.5 GHz data is used for the algorithm of standard products processing. 6.925 GHz and 10.65 GHz data are used for research product, which is provided from EORC. The physical quantity unit is m/s.Also, the quality flag for each observation point (Pixel Data Quality) is stored.The provided format is HDF5.

Spatial resolution is 10 km. The current version of the product is "Version 8". The generation unit is scene (defined as a half orbit).