Does laboratory‐scale physics obstruct the development of a theory for climate?

Essex, Christopher

doi:10.1002/jgrd.50195

Cited by 8 publications

(4 citation statements)

References 26 publications

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“…Empirically based reports of validation failure in complex general-circulation models abound in the journals [14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29]. Most recently, Zhang et al [30] reported that some 93.4 % of altocumulus clouds observed by collocated CALIPSO and CloudSat satellites cannot be resolved by climate models with a grid resolution [1°(110 km).…”

Section: Empirical Evidence Of Models Running Hotmentioning

confidence: 99%

Why models run hot: results from an irreducibly simple climate model

et al. 2015

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An irreducibly simple climate-sensitivity model is designed to empower even non-specialists to research the question how much global warming we may cause. In 1990, the First Assessment Report of the Intergovernmental Panel on Climate Change (IPCC) expressed ''substantial confidence'' that near-term global warming would occur twice as fast as subsequent observation. Given rising CO 2 concentration, few models predicted no warming since 2001. Between the pre-final and published drafts of the Fifth Assessment Report, IPCC cut its near-term warming projection substantially, substituting ''expert assessment'' for models' near-term predictions. Yet its long-range predictions remain unaltered. The model indicates that IPCC's reduction of the feedback sum from 1.9 to 1.5 W m -2 K -1 mandates a reduction from 3.2 to 2.2 K in its central climate-sensitivity estimate; that, since feedbacks are likely to be net-negative, a better estimate is 1.0 K; that there is no unrealized global warming in the pipeline; that global warming this century will be \1 K;and that combustion of all recoverable fossil fuels will cause \2.2 K global warming to equilibrium. Resolving the discrepancies between the methodology adopted by IPCC in its Fourth and Fifth Assessment Reports that are highlighted in the present paper is vital. Once those discrepancies are taken into account, the impact of anthropogenic global warming over the next century, and even as far as equilibrium many millennia hence, may be no more than one-third to one-half of IPCC's current projections.

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Section: Empirical Evidence Of Models Running Hotmentioning

confidence: 99%

Why models run hot: results from an irreducibly simple climate model

et al. 2015

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“…Thus, the slow time results in [ 2 ], wherein temperature fails to exist because of heavy tails, are not physically problematic. However, they do raise concerns about existing physical models for slowly varying noisy processes such as climate and weather [ 9 , 10 , 11 ].…”

Section: No Temperature No State Function No Equilibriummentioning

confidence: 99%

Tales of Tails

Essex

Andresen

2023

Entropy

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Typical human-scaled considerations of thermodynamic states depend primarily on the core of associated speed or other relevant distributions, because the wings of those distributions are so improbable that they cannot contribute significantly to averages. However, for long timescale regimes (slow time), previous papers have shown otherwise. Fluctuating local equilibrium systems have been proven to have distributions with non-Gaussian tails demanding more careful treatment. That has not been needed in traditional statistical mechanics. The resulting non-Gaussian distributions do not admit notions such as temperature; that is, a global temperature is not defined even if local regimes have meaningful temperatures. A fluctuating local thermodynamic equilibrium implies that any local detector is exposed to sequences of local states which collectively induce the non-Gaussian forms. This paper shows why tail behavior is observationally challenging, how the convolutions that produce non-Gaussian behavior are directly linked to time-coarse graining, how a fluctuating local equilibrium system does not need to have a collective temperature, and how truncating the tails in the convolution probability density function (PDF) produces even more non-Gaussian behaviors.

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“…When all of these vector fields are the same, there is one reference an observer could ride in where all currents stop. The term “generalized wind” was later coined to describe these vector fields [ 3 ]. When a single “generalized wind” velocity exists for all currents there exists a frame where no process occurs.…”

Section: Introductionmentioning

confidence: 99%

Radiative Transfer and Generalized Wind

Essex

Das

2020

Entropy

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Dissimilar flows can be compared by exploiting the fact that all flux densities divided by their conjugate volume densities form velocity fields, which have been described as generalized winds. These winds are an extension of the classical notion of wind in fluids which puts these distinct processes on a common footing, leading to thermodynamical implications. This paper extends this notion from fluids to radiative transfer in the context of a classical two-stream atmosphere, leading to such velocities for radiative energy and entropy. These are shown in this paper to exhibit properties for radiation previously only thought of in terms of fluids, such as the matching of velocity fields where entropy production stops.

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Does laboratory‐scale physics obstruct the development of a theory for climate?

Cited by 8 publications

References 26 publications

Why models run hot: results from an irreducibly simple climate model

Why models run hot: results from an irreducibly simple climate model

Tales of Tails

Radiative Transfer and Generalized Wind

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