Quasi-Equilibrium Dynamics of the Tropical Atmosphere

Abstract The hypothesis of convective quasi-equilibrium (CQE) has dominated thinking about the interaction between deep moist convection and the environment for at least two decades. In this view, deep convection develops or decays almost instantly to remove any changes of convective instability, making the tropospheric temperature always tied to the boundary layer moist static energy. The present study examines the validity of the CQE hypothesis at different vertical levels using long-term sounding data from tropical convection centers. The results show that the tropical atmosphere is far from the CQE with much weaker warming in the middle and upper troposphere associated with the increase of boundary layer moist static energy. This is true for all the time scales resolved by the observational data, ranging from hourly to interannual and decadal variability. It is possibly caused by the ubiquitous existence of shallow convection and stratiform precipitation, both leading to sign reversal of heating from lower to upper troposphere. The simulations by 42 global climate models from phases 3 and 5 of the Coupled Model Intercomparsion Project (CMIP3 and CMIP5) are also analyzed and compared with the observations.

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Equilibrium Dynamics in a Model of Growth and Spatial Agglomeration

SSRN Electronic Journal ◽

10.2139/ssrn.3290371 ◽

2018 ◽

Author(s):

Shota Fujishima ◽

Daisuke Oyama

Keyword(s):

Spatial Agglomeration ◽

Equilibrium Dynamics

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Temperature chaos is present in off-equilibrium spin-glass dynamics

Communications Physics ◽

10.1038/s42005-021-00565-9 ◽

2021 ◽

Vol 4 (1) ◽

Author(s):

Marco Baity-Jesi ◽

Enrico Calore ◽

Andrés Cruz ◽

Luis Antonio Fernandez ◽

José Miguel Gil-Narvion ◽

...

Keyword(s):

Spin Glass ◽

Dynamic Effect ◽

Large Degree ◽

Equilibrium Temperature ◽

Experimental Conditions ◽

Temperature Changes ◽

Equilibrium Dynamics ◽

Glass Dynamics ◽

Extreme Sensitivity ◽

Non Equilibrium

AbstractExperiments featuring non-equilibrium glassy dynamics under temperature changes still await interpretation. There is a widespread feeling that temperature chaos (an extreme sensitivity of the glass to temperature changes) should play a major role but, up to now, this phenomenon has been investigated solely under equilibrium conditions. In fact, the very existence of a chaotic effect in the non-equilibrium dynamics is yet to be established. In this article, we tackle this problem through a large simulation of the 3D Edwards-Anderson model, carried out on the Janus II supercomputer. We find a dynamic effect that closely parallels equilibrium temperature chaos. This dynamic temperature-chaos effect is spatially heterogeneous to a large degree and turns out to be controlled by the spin-glass coherence length ξ. Indeed, an emerging length-scale ξ* rules the crossover from weak (at ξ ≪ ξ*) to strong chaos (ξ ≫ ξ*). Extrapolations of ξ* to relevant experimental conditions are provided.

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