Taylor, Gerald D., authorCooperative Institute for Research in the Atmosphere (Fort Collins, Colo.), publisher2022-08-022022-08-021991-05https://hdl.handle.net/10217/235492May 1991.In this note a general description of the application of the adjoint method for four dimensional data assimilation is given. The main focus of this discussion is that this method when applied to a discrete model is simply an application of the chair rule of multivariate calculus to compute the gradient of a real valued function of several variables. Several different time differencing schemes are considered, as well as, two examples of discrete models.reportsengCopyright and other restrictions may apply. User is responsible for compliance with all applicable laws. For information about copyright law, please see https://libguides.colostate.edu/copyright.Meteorology -- Data processingNumerical weather forecastingText