Open AccessLarge‐eddy simulation in an anelastic framework with closed water and entropy balances
Author(s) -
Pressel Kyle G.,
Kaul Colleen M.,
Schneider Tapio,
Tan Zhihong,
Mishra Siddhartha
Publication year - 2015
Publication title -
journal of advances in modeling earth systems
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.03
H-Index - 58
ISSN - 1942-2466
DOI - 10.1002/2015ms000496
Subject(s) - discretization , large eddy simulation , computer science , mathematics , adiabatic process , mechanics , statistical physics , physics , mathematical analysis , thermodynamics , turbulence
A large‐eddy simulation (LES) framework is developed for simulating the dynamics of clouds and boundary layers with closed water and entropy balances. The framework is based on the anelastic equations in a formulation that remains accurate for deep convection. As prognostic variables, it uses total water and entropy, which are conserved in adiabatic and reversible processes, including reversible phase changes of water. This has numerical advantages for modeling clouds, in which reversible phase changes of water occur frequently. The equations of motion are discretized using higher‐order weighted essentially nonoscillatory (WENO) discretization schemes with strong stability preserving time stepping. Numerical tests demonstrate that the WENO schemes yield simulations superior to centered schemes, even when the WENO schemes are used at coarser resolution. The framework is implemented in a new LES code written in Python and Cython, which makes the code transparent and easy to use for a wide user group.