The analytical four-dimensional ensemble variational (A-4DEnVar) data assimilation scheme inherits the advantages of the conventional four-dimensional variational (4D-Var) data assimilation scheme and removes the adjoint model. However. compatible operational improvements such as the reduction of the computational costs and the localization method should be considered when it is used ... https://www.roneverhart.com/ESP-LTD-SD-2-Sammy-Duet-Signature-Model-Electric-Guitar-Black-p20045/