Large‐eddy simulation in an anelastic framework with closed water and entropy balances. (26th September 2015)

• Record Type: Journal Article
• Authors: Pressel, Kyle G.; Kaul, Colleen M.; Schneider, Tapio; Tan, Zhihong; Mishra, Siddhartha
• Is Part Of: Journal of advances in modeling earth systems. Volume 7:Number 3(2015:Sep.)
• Page Start: 1425
• Page End: 1456
• Publication Date: 2015-09-26
• Subjects: large‐eddy simulation -- clouds -- entropy -- moist thermodynamics -- numerical methods; Geological modeling -- Periodicals; Climatology -- Periodicals; Geochemical modeling -- Periodicals; 551.5011
• DOI: 10.1002/2015MS000496
• Languages: English
• ISSNs: 1942-2466

Abstract

Abstract: 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. Key Points: An anelastic framework for LES with closed water and entropy balances is developed State‐of‐the‐art numerical techniques yield superior results to traditional techniques Implementation in Python and Cython makes the framework easy to use