Direct retrieval of line-of-sight atmospheric structure from limb soundingobservations

Optimal estimation of atmospheric temperature and composition from limb sou nding observations is extended to the direct retrieval of line-of-sight atm ospheric structure that can be obtained in certain limb viewing geometries. The approach is to divide the dataset into slightly overlapping chunks of several atmospheric profiles and retrieve estimates for all profiles concur rently. The method is made efficient due to the sparse nature of the matric es involved. In the case where the number of radiance measurements is signi ficantly larger than the length of the state vector, the computational effo rt scales linearly with the number of profiles in the chunk. Prototype simu lations, done for the EOS MLS experiment, show that application of this met hod can give significant improvements in accuracy.