Variation characteristics of entropy production in geophysical phenomena

2016 Fiscal Year Final Research Report

• Project/Area Number: 25400465
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Meteorology/Physical oceanography/Hydrology
• Research Institution: Hiroshima University
• Principal Investigator: Ozawa Hisashi 広島大学, 総合科学研究科, 准教授 (30371743)
• Co-Investigator(Renkei-kenkyūsha): SAKUMA Hirofumi 独立行政法人海洋研究開発機構, 地球環境変動領域, チームリーダー (70359214)
• Research Collaborator: NIVEN Robert The University of New South Wales, Associate Professor ; KLEIDON Axel Max-Planck-Institute for Biogeochemistry, Group Leader
• Project Period (FY): 2013-04-01 – 2017-03-31
• Keywords: 地球科学現象 / エントロピー生成 / 流体系 / 熱帯低気圧 / 熱対流

Outline of Final Research Achievements

Entropy production due to irreversible transports of heat and momentum is investigated based on balance equations of energy and momentum in a fluid system. It is shown that entropy production always decreases with time and becomes a minimum when the dimensionless parameter that determines the stability of a fluid system is less than a certain critical value. In contrast, entropy production tends to be a maximum when the parameter becomes larger than the critical value and nonlinear advection becomes dominant over linear diffusion. As typical examples of geophysical phenomena, we investigate strength and heat transport properties of tropical cyclones and atmospheric convection. It is found that the strength and variation characteristics of these systems can be understood from a state in which the rate of entropy production due to convective movement is at a maximum.

Free Research Field

数物系科学，地球惑星科学，非平衡熱力学