Detailed three-dimensional isentropic analysis using an objective cross-sectional approach

Abstract

An approach is presented which is designed to give detailed, computationally-efficient meteorological objective analyses over data-rich regions, with results independent of numerical model influences. Observed station data and interstation gradients are used to interpolate pressure, wind, and moisture information from vertical cross-sections onto isentropci surfaces by means of cubic polynomials. Three-dimensional grid-point analyses of mass and moisture are obtained by first constructing a series of nearly parallel vertical cross sections over a specified area, and then filling in the space between adjacent vertical analyses by employing a second set of nearly orthogonal cross sections. Gradients obtained from the mass analyses are then combined with observed wind data to obtain thermally-consistent observed wind analyses. It is concluded that the resulting analyses are useful for preserving significnat horizontal and vertical gradients, such as those associated with jet-streak systems. Examples are given which verify the applicability of this analysis technique to radiosonde data.