scholarly journals A model of surface heat fluxes based on the theory of maximum entropy production

2009 ◽  
Vol 45 (11) ◽  
Author(s):  
J. Wang ◽  
Rafael L. Bras
Keyword(s):  
Entropy Production ◽  
Maximum Entropy ◽  
Surface Heat ◽  
Heat Fluxes ◽  
Maximum Entropy Production ◽  
Surface Heat Fluxes

scholarly journals The Atmospheric Response to Surface Heating under Maximum Entropy Production

2014 ◽  
Vol 71 (6) ◽  
pp. 2204-2220
Author(s):  
A. Gjermundsen ◽  
J. H. LaCasce ◽  
L. S. Graff
Keyword(s):  
Entropy Production ◽  
Maximum Entropy ◽  
Heat Transport ◽  
General Circulation ◽  
Heat Fluxes ◽  
Storm Tracks ◽  
Atmospheric Response ◽  
Maximum Entropy Production ◽  
Surface Temperatures ◽  
Low Latitudes

Abstract In numerous studies, midlatitude storm tracks have been shown to shift poleward under global warming scenarios. Among the possible causes, changes in sea surface temperature (SST) have been shown to affect both the intensity and the position of the tracks. Increased SSTs can increase both the lateral heating occurring in the tropics and the midlatitude temperature gradients, both of which increase tropospheric baroclinicity. To better understand the response to altered SST, a simplified energy balance model (EBM) is used. This employs the principal of maximum entropy production (MEP) to determine the meridional heat fluxes in the atmosphere. The model is similar to one proposed by Paltridge (1975) but represents only the atmospheric response (the surface temperatures are fixed). The model is then compared with a full atmospheric general circulation model [Community Atmosphere Model, version 3 (CAM3)]. In response to perturbed surface temperatures, EBM exhibits similar changes in (vertically integrated) air temperature, convective heat fluxes, and meridional heat transport. However, the changes in CAM3 are often more localized, particularly at low latitudes. This, in turn, results in a shift of the storm tracks in CAM3, which is largely absent in EBM. EBM is more successful, however, at representing the response to changes in high-latitude heating or cooling. Therefore, MEP is evidently a plausible representation for heat transport in the midlatitudes, but not necessarily at low latitudes.

scholarly journals Vertical and horizontal processes in the global atmosphere and the maximum entropy production conjecture

2012 ◽  
Vol 3 (1) ◽  
pp. 19-32 ◽  
Author(s):  
S. Pascale ◽  
J. M. Gregory ◽  
M. H. P. Ambaum ◽  
R. Tailleux ◽  
V. Lucarini
Keyword(s):  
Entropy Production ◽  
Maximum Entropy ◽  
Heat Transport ◽  
Large Scale ◽  
Vertical Structure ◽  
Magnitude Estimate ◽  
Heat Fluxes ◽  
Box Model ◽  
Maximum Entropy Production ◽  
Vertical Heat

Abstract. The objective of this paper is to reconsider the Maximum Entropy Production conjecture (MEP) in the context of a very simple two-dimensional zonal-vertical climate model able to represent the total material entropy production due at the same time to both horizontal and vertical heat fluxes. MEP is applied first to a simple four-box model of climate which accounts for both horizontal and vertical material heat fluxes. It is shown that, under condition of fixed insolation, a MEP solution is found with reasonably realistic temperature and heat fluxes, thus generalising results from independent two-box horizontal or vertical models. It is also shown that the meridional and the vertical entropy production terms are independently involved in the maximisation and thus MEP can be applied to each subsystem with fixed boundary conditions. We then extend the four-box model by increasing its resolution, and compare it with GCM output. A MEP solution is found which is fairly realistic as far as the horizontal large scale organisation of the climate is concerned whereas the vertical structure looks to be unrealistic and presents seriously unstable features. This study suggest that the thermal meridional structure of the atmosphere is predicted fairly well by MEP once the insolation is given but the vertical structure of the atmosphere cannot be predicted satisfactorily by MEP unless constraints are imposed to represent the determination of longwave absorption by water vapour and clouds as a function of the state of the climate. Furthermore an order-of-magnitude estimate of contributions to the material entropy production due to horizontal and vertical processes within the climate system is provided by using two different methods. In both cases we found that approximately 40 mW m−2 K−1 of material entropy production is due to vertical heat transport and 5–7 mW m−2 K−1 to horizontal heat transport.

Trends of land surface heat fluxes on the Tibetan Plateau from 2001 to 2012

2017 ◽  
Vol 37 (14) ◽  
pp. 4757-4767 ◽  
Author(s):  
Cunbo Han ◽  
Yaoming Ma ◽  
Xuelong Chen ◽  
Zhongbo Su
Keyword(s):  
Tibetan Plateau ◽  
Land Surface ◽  
Surface Heat ◽  
Heat Fluxes ◽  
The Tibetan Plateau ◽  
Surface Heat Fluxes ◽  
Land Surface Heat Fluxes
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