Meso-Synoptic Scale Interactions during AVE/SESAME I, 10–11 April 1979. Part I: Theoretical Development of Interaction Equations

Abstract

This is the first of two companion papers that describe the development and application of a set of kinetic energy budget equations which explicitly account for meso-synoptic scale interactions. The present paper focuses on the theoretical development of the equations and discusses a particular type of dataset to which the equations will be applied in the second paper. The kinetic energy content for the total observable flow (kT) is partitioned into components representing large (synoptic) scales of motion (kL), δ-scales of motion (differences between the total and large-scale flow denoted as kδ), and interactions among features within the two scales. Thus, kT = kL + kδ + (VL·Vδ). The Eulerian form of the kinetic energy budget is derived for each of these components. A Barnes objective analysis scheme is used to obtain two gridded datasets, one of which is based on all the data taken in the AVE/SESAME I regional scale network on 10?11 April 1979. This SES network consisted of 23 NWS and 16 supplementary stations. The other dataset is based on data taken only at the NWS stations. All kinetic energy budget terms are computed from the two datasets. The total flow is calculated from SES, the large-scale flow from NWS, the δ-scale flow from the difference between SES and NWS, and the interaction flow from the scalar product terms of the NWS and δ-scales. Both datasets contain 1°?1° latitude-longitude values of observed variables and kinematically-derived vertical ?-velocity (?) at the surface and at 50 mb increments from 950?100 mb for each of the 3-h intervals during the 24-hour SESAME period being investigated.