Study on Hyper-spectral Atmospheric Infrared Sounder Assimilation

Hyper-spectral Atmospheric Infrared Sounder has many channels. Although, it has been carried out channel selection in the actual application process, but compared with the previous detector, the channel also seems more and thus easy to weak correlation between channels, which is not obey classical variational assimilation theory requires observation error is not related. Hyper-spectral sounder covering CO2 and water vapor absorption band channels, the nonlinear of water vapor channel brightness temperature is strong, the practical application of these channel combinations into the assimilation system together, the brightness temperature information mutual influence and feedback among channels are more complex. Different from the classical variational assimilation that given observation error is not change later, using the observational error re-estimation and robust variational assimilation based on Huber function to study the hyper-spectral sounder brightness temperature assimilation. The ideal experiments show that the observation error re-estimates and robust variational method assimilate hyper-spectral atmospheric infrared sounder can get better assimilation effect than the classical one.