scholarly journals Entropy budget of the ocean system

2004 ◽  
Vol 31 (14) ◽  
Author(s):  
Youfang Yan
Keyword(s):  
Universe ◽  
2017 ◽  
Vol 3 (3) ◽  
pp. 58 ◽  
Author(s):  
Ana Alonso-Serrano ◽  
Matt Visser

2019 ◽  
Vol 46 (8) ◽  
pp. 4476-4484
Author(s):  
Ding Ma ◽  
Adam H. Sobel ◽  
Zhiming Kuang ◽  
Martin S. Singh ◽  
Ji Nie

2011 ◽  
Vol 2 (2) ◽  
pp. 179-190 ◽  
Author(s):  
P. Porada ◽  
A. Kleidon ◽  
S. J. Schymanski

Abstract. Hydrological processes are irreversible and produce entropy. Hence, the framework of non-equilibrium thermodynamics is used here to describe them mathematically. This means flows of water are written as functions of gradients in the gravitational and chemical potential of water between two parts of the hydrological system. Such a framework facilitates a consistent thermodynamic representation of the hydrological processes in the model. Furthermore, it allows for the calculation of the entropy production associated with a flow of water, which is proportional to the product of gradient and flow. Thus, an entropy budget of the hydrological cycle at the land surface is quantified, illustrating the contribution of different processes to the overall entropy production. Moreover, the proposed Principle of Maximum Entropy Production (MEP) can be applied to the model. This means, unknown parameters can be determined by setting them to values which lead to a maximisation of the entropy production in the model. The model used in this study is parametrised according to MEP and evaluated by means of several observational datasets describing terrestrial fluxes of water and carbon. The model reproduces the data with good accuracy which is a promising result with regard to the application of MEP to hydrological processes at the land surface.


2004 ◽  
Vol 14 (12) ◽  
pp. 1088-1094
Author(s):  
Zijun Gan ◽  
Youfang Yan ◽  
Yiquan Qi

2009 ◽  
Vol 66 (1) ◽  
pp. 148-158 ◽  
Author(s):  
George H. Bryan ◽  
Richard Rotunno

Abstract Using a time-dependent axisymmetric numerical model, the authors evaluate whether high-entropy air near the surface in hurricane eyes can substantially increase hurricanes’ maximum intensity. This local high-entropy anomaly is ultimately created by surface entropy fluxes in the eye. Therefore, simulations are conducted in which these surface fluxes are set to zero; results show that the high-entropy anomaly is eliminated, yet the axisymmetric tangential wind speed is only slightly weakened (by ∼4%, on average). These results contradict the hypothesis that transport of high-entropy air from the eye into the eyewall can significantly increase the maximum axisymmetric intensity of hurricanes. In fact, all simulations (with or without high-entropy anomalies) have an intensity that is 25–30 m s−1 higher than Emanuel’s theoretical maximum intensity. Further analysis demonstrates that less then 3% of the total surface-entropy input to the hurricane comes from the eye, and therefore the total magnitude of entropy transport between the eye and eyewall is a negligible component of the entropy budget of the simulated hurricanes. This latter finding is consistent with a cursory comparison with observations.


Entropy ◽  
2014 ◽  
Vol 16 (7) ◽  
pp. 3710-3731 ◽  
Author(s):  
Paul Stoy ◽  
Hua Lin ◽  
Kimberly Novick ◽  
Mario Siqueira ◽  
Jehn-Yih Juang

2011 ◽  
Vol 2 (1) ◽  
pp. 87-103 ◽  
Author(s):  
N. A. Brunsell ◽  
S. J. Schymanski ◽  
A. Kleidon

Abstract. As a system is moved away from a state of thermodynamic equilibrium, spatial and temporal heterogeneity is induced. A possible methodology to assess these impacts is to examine the thermodynamic entropy budget and assess the role of entropy production and transfer between the surface and the atmosphere. Here, we adopted this thermodynamic framework to examine the implications of changing vegetation fractional cover on land surface energy exchange processes using the NOAH land surface model and eddy covariance observations. Simulations that varied the relative fraction of vegetation were used to calculate the resultant entropy budget as a function of fraction of vegetation. Results showed that increasing vegetation fraction increases entropy production by the land surface while decreasing the overall entropy budget (the rate of change in entropy at the surface). This is accomplished largely via simultaneous increase in the entropy production associated with the absorption of solar radiation and a decline in the Bowen ratio (ratio of sensible to latent heat flux), which leads to increasing the entropy export associated with the latent heat flux during the daylight hours and dominated by entropy transfer associated with sensible heat and soil heat fluxes during the nighttime hours. Eddy covariance observations also show that the entropy production has a consistent sensitivity to land cover, while the overall entropy budget appears most related to the net radiation at the surface, however with a large variance. This implies that quantifying the thermodynamic entropy budget and entropy production is a useful metric for assessing biosphere-atmosphere-hydrosphere system interactions.


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