Ein variierbares, objektives Analyseschema zur Analyse der ALPEX-Daten

Abstract

A scheme for analysis of the ALPEX II-b data set is described. Using the calculus of variations in developing the analysis equations, considerations were consistent with requirements necessary for computing budgets for various meteorological quantities. One constraint which employs full equations of motion, reduces the momentum residual to any desired level based on selection of a weighting function. Time tendencies are assumed to be observed, while nonlinear terms can be observed or iterated. At the same time, mass continuity is completely imposed by application of a strong constraint. Approximation of terrain as a series of blocks in thex, y, p domain insures that the model terrain will block the flow to the maximum extent possible in a way consistent with the Alpine range. Comparative analyses are presented illustrating how coupling the variables increases resolution of fine scale features like fronts and jet maxima. Comparison with independently collected research aircraft data over the Mediterranean Sea also shows how the scheme can provide improved analysis even over data sparse areas. Derived vertical motion fields compare well with middle and upper level cloud patterns for a case of rapid cyclogenesis.