An iterative variational method for adjusting isobaric wind and geopotential to satisfy the balance equation

"If the initial wind and geopotential fields are sufficiently out-of-balance, a primitive equation, prediction model will produce a gravitational-inertial oscillation as a result of the implied need for a "geostrophic adjustment." To reduce the amplitude of such oscillations, one may seek to impose the "balance-equation" upon the initial data. The balance-equation may be used to calculate the wind from the geopotential, or vice versa. In either direction, one may find that the changes in the initial data are somewhat excessive. In this note, we discuss a variational method for adjusting both the wind and the geopotential so that the final fields satisfy the balance-equation. The mutual adjustment is carried out so as to minimize the areal average of the change in actual and geostrophic kinetic energy. By allowing both the wind and the geopotential to be modified, one hopes to minimize the departures of both fields from the initial analysis"--Introduction. J. P. Gerrity, R. T. Chu. "October 1978." "This is an unreviewed manuscript, primarily intended for informal exchange of information among NMC staff members." System requirements: Adobe Acrobat Reader. 1978 NWS (National Weather Service) Library Public Domain 1931