Hisashi Ozawa's research while affiliated with Asia-Pacific Network for Global Change Research and other places

Publications (3)

Article
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The long-term mean properties of the global climate system and those of turbulent fluid systems are reviewed from a thermodynamic viewpoint. Two general expressions are derived for a rate of entropy production due to thermal and viscous dissipation (turbulent dissipation) in a fluid system. It is shown with these expressions that maximum entropy pr...
Article
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The dissipative properties of turbulence, including those of the global climate system, have been investigated from a thermodynamical viewpoint. It is found that the steady-state properties of the present climate [1], transport properties of turbulence [2], and variations of a regime of thermal convection [3,4] can be explained to a certain extent...
Article
Full-text available
Vertical heat transport through thermal convection of the earth's atmosphere is investigated from a thermodynamic viewpoint. The postulate for convection considered here is that the global-mean state of the atmosphere is stabilized at a state of maximum entropy increase in a whole system through convective transport of sensible and latent heat from...

Citations

... The success of this approach led to a great deal of interest in the late 1970s and early 1980s, but was also criticized for lacking a mechanism by which the MEP state was achieved, and for producing meridional heat transports which were independent of well-known constraints on atmospheric dynamics, such as the planetary rotation rate (Rodgers 1976). There has been a recent resurgence in the application of MEP principles to the climate system (Ozawa et al. 2003; Paltridge et al. 2007), for two main reasons. Firstly, Lorenz et al. (2001) showed that the equator-to-pole temperature differences on Titan and Mars, as well as on Earth, can be reproduced by applying an MEP selection principle to a simple two-box model. ...
... However, the vast majority of the entropy production on Earth is associated with vertical entropy fluxes . When MEP is applied to vertical entropy exchange, it often gives unphysical predictions; for example, temperature distributions that are gravitationally unstable or atmospheric layers that destroy entropy (Chang, 2019;Herbert et al., 2013;Ozawa and Ohmura, 1997;Pujol and Fort, 2002). As above, this suggests a need to include additional constraints to the MEP framework. ...
... Applying the fluctuation theorem (FT, a generalized second law) [50], we deduce that the admittance would be self-propelled on millennial timescale toward MEP, a process termed "MEP adjustment". It entails as a special case that the steady-state climate is characterized by MEP [51][52][53], but the time evolution is needed for addressing abrupt climate change. In addition, FT is of considerable mathematical rigor and has been tested in laboratory [54,55], so its deductive outcome in the steady-state MEP further strengthens the latter's physical basis. ...