Diagnostics and decomposition of atmospheric disturbances in a planar flow are considered in this work. The study examines a situation in which the stationary equilibrium temperature of a gas may depend on the vertical coordinate due to external forces. The relations connecting perturbations are analytically established. These perturbations specify acoustic and entropy modes in an arbitrary stratified gas affected by a constant mass force. The diagnostic relations link acoustic and entropy modes, and are independent of time. Hence, they provide an ability to decompose the total vector of perturbations into acoustic and non-acoustic (entropy) parts, and to establish the distribution of energy between the sound and entropy modes, uniquely at any instant. The total energy of a flow is hence determined in its parts which are connected with acoustic and entropy modes. The examples presented in this work consider the equilibrium temperature of a gas, which linearly depends on the vertical coordinate. Individual profiles of acoustic and entropy parts for some impulses are illustrated with plots.

JO - Archives of Acoustics L1 - http://www.journals.pan.pl/Content/108121/PDF/123921.pdf L2 - http://www.journals.pan.pl/Content/108121 PY - 2018 IS - No 3 EP - 503 KW - acoustics of non-uniform media KW - initialization of hydrodynamic field A1 - Leble, Sergey A1 - Perelomova, Anna PB - Committee on Acoustics PAS, PAS Institute of Fundamental Technological Research, Polish Acoustical Society VL - vol. 43 JF - Archives of Acoustics DA - 2018.09.25 T1 - Decomposition of Acoustic and Entropy Modes in a Non-Isothermal Gas Affected by a Mass Force SP - 497 UR - http://www.journals.pan.pl/dlibra/docmetadata?id=108121 DOI - 10.24425/123921 ER -