Sentences with phrase «of emergent constraints»

I would first have to ask whether the methods of emergent constraints are used commonly outside of climate science.

Part 1 of this article the nature and validity of emergent constraints [1] on equilibrium climate sensitivity (ECS) in GCMs were discussed, drawing mainly on the analysis and assessment of 19 such constraints in Caldwell et al. (2018), [2] who concluded that only four of them were credible.

In Part 1 of this article the nature and validity of emergent constraints [1] on equilibrium climate sensitivity (ECS) in GCMs were discussed, drawing mainly on the analysis and assessment of 19 such constraints in Caldwell et al. (2018), [2] who concluded that only four of them were credible.

And beyond the post-facto model evaluation, it will be interesting to see whether new climate models will take advantage of emergent constraints to improve their simulation of present - day climate and to reduce uncertainties in future projections.

This diversity of emergent constraints highlights the commitment of the climate community to narrowing uncertainties in climate projections.

An early application of emergent constraints concerned the snow - albedo feedback.

Other branches of climate science use the concept of emergent constraints.

Since the AR4, there are a few examples of emergent constraints where observations are used to constrain multi-model ensemble projections.

In a previous post, I described the concept of emergent constraints, which allow us to narrow uncertainties in climate change projections through empirical relationships that relate a model's climate response to observable metrics.

In Part 1 of this article the nature and validity of emergent constraints [i] on equilibrium climate sensitivity (ECS) in GCMs were discussed, drawing mainly on the analysis and assessment of 19 such constraints in Caldwell et al (2018; henceforth Caldwell), [ii] who concluded that only four of them were credible.

In Part 1 of this article the nature and validity of emergent constraints [1] on equilibrium climate sensitivity (ECS) in GCMs were discussed, drawing mainly on the analysis and assessment of 19 such constraints in Caldwell et al. (2018), [2] who concluded that only four of them were credible.

Bracegirdle, T. J. & Stephenson, D. B. On the robustness of emergent constraints used in multimodel climate change projections of Arctic warming.

The credibility of an emergent constraint relies upon the strength of the statistical relationship, a clear understanding of the mechanisms underlying the relationship, and the accuracy of observations.

Despite this successful application of an emergent constraint, the generation of models that followed (CMIP5) continued to exhibit a large spread in seasonal variability of snow - albedo changes (Qu and Hall 2014).

Not exact matches

There are many examples of emergent, overarching constraints that govern the interactions among the parts of a physical system and thus alter the distribution of energy within the system.

Borodina, A., Fischer, E. M. & Knutti, R. Emergent constraints in climate projections: a case study of changes in high - latitude temperature variability.

Personally, I'm doubtful that emergent constraint approaches generally tell one much about the relationship to the real world of aspects of model behaviour other than those which are closely related to the comparison with observations.

There have been quite a number of papers published in recent years concerning «emergent constraints» on equilibrium climate sensitivity (ECS) in comprehensive global climate models (GCMs), of both the current (CMIP5) and previous (CMIP3) generations.

We shall see in this 3 - part article that emergent constraint approaches have the potential to offer useful insights into cloud behaviour, however the main focus will be on to what extent they narrow the uncertainty range of ECS in GCMs.

Caldwell regarded a proposed emergent constraint as not credible if it lacks an identifiable physical mechanism; is not robust to change of model ensemble; or if its correlation with ECS is not due to its proposed physical mechanism.

An extract of the rows of Table 1 of Part 1 detailing those four emergent constraints is given below.

These transient constraints have tended to come in lower than the other estimates based on paleo - climate or emergent constraints, and thus have been embraced by (let's say) more «optimistic» commentators (though until the mismatches are resolved it would be premature to only favor only one class of results).

5) As Kevin Cowtan rightly says, we did check that the coverage of the observational data in HadCRUT4 did not affect our emergent constraint.

Keeping only models with enough structural differences often reduces the reliability of identified emergent constraints.

Finally, the relevance of constrained climate - change projections depends on statistical conditions that characterize emergent constraints.

The whole goal of emergent - constraint hunting is to find predictors which we have reason to expect are tightly - related to our predictand.

Regarding the emergent constraint used in Brient & Schneider (2016), it is noteworthy that if the models are weighted by reference to their consistency with the data, regression of ECS on TLC reflection variability explains almost none of the intermodel ECS variation — the R - squared is negligible.

What many previous emergent - constraint studies have done is to take such a band of observations and project it onto the vertical ECS axis using the estimated regression line between ECS and the natural fluctuations, taking into account uncertainties in the estimated regression model.

The plain - language explanations of the various limitations of the linear regression approach to emergent constraints were especially useful.

Various attempts have been made to narrow the likely range of the equilibrium climate sensitivity (ECS) through exploitation of «emergent constraints.»

Personally, I'm doubtful that emergent constraint approaches generally tell one much about the relationship to the real world of aspects of model behaviour other than those which are closely related to the comparison with observations.

As with all emergent constraints, this means it can be difficult to use natural variations to constrain the climate response of clouds.

It is also the first paper introducing the concept of an «emergent constraint» in the climate sciences.

The success of the Hall and Qu study paved the way for a number of studies seeking emergent constraints for equilibrium climate sensitivity (ECS).

Conversely, many emergent constraints on ECS can be understood as encoding properties of shortwave low - cloud feedbacks (Qu et.

The three main criteria for a robust emergent constraint are satisfied: the physical mechanisms are well understood, the statistical relationship between the quantities of interest is strong, and uncertainties in the observed variations are weak, allowing Hall and Qu to constrain the snow - albedo feedback under global warming.

Correcting for precipitation biases in the tropical western Pacific using an emergent constraint methodology, however, reduces the magnitude of these increases by ∼ 50 %.

«Each of these subsystems has a host of known and unknown forcings, interactions, phase transitions, limitations, resonances, couplings, response times, feedbacks, natural cycles, emergent phenomena, constructal constraints, and control systems.

There have been quite a number of papers published in recent years concerning «emergent constraints» on equilibrium climate sensitivity (ECS) in comprehensive global climate models (GCMs), of both the current (CMIP5) and previous (CMIP3) generations.

We shall see in this 3 - part article that emergent constraint approaches have the potential to offer useful insights into cloud behaviour, however the main focus will be on to what extent they narrow the uncertainty range of ECS in GCMs.

[16] Qu, X., A. Hall, A. M. DeAngelis, M. D. Zelinka, S. A. Klein, H. Su, B. Tian, and C. Zhai, 2018: On the emergent constraints of climate sensitivity.

It is interesting that Tapio Schneider, the joint author of the Brient Alb paper, with considerable mathematical / statistical abilities, advocates caution regarding emergent constraint studies.

The dependence of sensitivity on the SST warming pattern, in GCMs at least, implies that even if a valid, strong emergent constraint on ECS in coupled GCMs were found, and there were no shortcomings in the atmospheric models of GCMs that satisfied the constraint, that would be insufficient to constrain real - world ECS.

[1] An emergent constraint on ECS is a quantitative measure of an aspect of GCMs» behaviour (a metric) that is well correlated with ECS values in an ensemble of GCMs and can be compared with observations, enabling the derivation of a narrower (constrained) range of GCM ECS values that correspond to GCMs whose metrics are statistically - consistent with the observations.

The Zhai methods have more shortcomings than those used by Brient & Schneider for their very similar emergent constraint, and the radical difference for four CMIP5 models in the two studies» assessment of consistency with the observational constraint from seasonal variations is a major concern.

All but one of the models from NCAR, GFDL, GISS, UKMO and MPI, perhaps the best - known modelling centres, are ruled out by the Brient Alb emergent constraint.

Caldwell regarded a proposed emergent constraint as not credible if it lacks an identifiable physical mechanism; is not robust to change of model ensemble; or if its correlation with ECS is not due to its proposed physical mechanism.

The main implication of the Brient Alb emergent constraint is that the relationship between deseasonalized tropical low - cloud SW reflection and SST in the low - sensitivity inmcm4 and GISS - E2 models is far from that observed.

That is also likely to be the case for emergent constraints that are proposed in future, since low cloud feedback is the dominant source of inter-model variation in ECS.

The Brient Alb and Zhai emergent constraints are very similar; they both involve the variation of low cloud SW reflection with SST.