Numerical simulation of thermally induced gyres in Lake Biwa

✍ Scribed by Yosuke Yamashiki; Michio Kumagai; Chunmeng Jiao; Iehisa Nezu; Saburo Matsui

• Publisher: John Wiley and Sons
• Year: 2003
• Tongue: English
• Weight: 502 KB
• Volume: 17
• Category: Article
• ISSN: 0885-6087
• DOI: 10.1002/hyp.1443

✦ Synopsis

Abstract

The formation process of three gyres in Lake Biwa, as observed using an acoustic Doppler current profiler, is simulated using three different SGS models: Smagorinsky Model, Dynamic Mixed Model (DMM) and Mixed Scaling Formulation Model (MSFM) based on very large eddy simulation (VLES). The driving force of gyre formation is assumed to be differential heating due to heat volume differences between the middle lake and shoreline areas. This condition is created in the simulation by setting the initial temperature distribution in the lake based on field observation data. The significant patterns of gyre formation are calculated both by DNM and MSFM. Owing to the huge disproportion of horizontal and vertical grid spacing, the isotropic subgrid scale (SGS) model (such as the Smagorinsky model) does not perform well when using normal grid spacing. According to the comparison between field observation data and numerical simulation, it is concluded that the surface heat transfer process is one of the main driving forces for gyre formation in Lake Biwa. Copyright © 2003 John Wiley & Sons, Ltd.