Mechanisms of marine low cloud sensitivity to idealized climate perturbations: A single‐LES exploration extending the CGILS cases

Bretherton, Christopher S.; Blossey, Peter N.; Jones, C. R.

doi:10.1002/jame.20019

Cited by 189 publications

(389 citation statements)

References 54 publications

Supporting

Mentioning

358

Contrasting

Order By: Relevance

“…Over decadal time-scales, Seethala et al (2015) find that observed tropical low-cloud changes can be well explained with a linear model using SST, EIS, and horizontal temperature advection as cloud-controlling factors. In large-eddy simulations, changes in shortwave radiation reflected by low clouds in response to the simultaneous changes in many cloud-controlling factors are within 10% of the linear sum of changes in simulations forced by individual cloud-controlling factors (Bretherton et al 2013).…”

Section: I4 Imprecise Statistical Modelingmentioning

confidence: 92%

Low-Cloud Feedbacks from Cloud-Controlling Factors: A Review

et al. 2017

View full text Add to dashboard Cite

The response to warming of tropical low-level clouds including both marine stratocumulus and trade cumulus is a major source of uncertainty in projections of future climate. Climate model simulations of the response vary widely, reflecting the difficulty the models have in simulating these clouds. These inadequacies have led to alternative approaches to predict low-cloud feedbacks. Here, we review an observational approach that relies on the assumption that observed relationships between low clouds and the ''cloud-controlling factors'' of the large-scale environment are invariant across time-scales. With this assumption, and given predictions of how the cloud-controlling factors change with climate warming, one can predict low-cloud feedbacks without using any model simulation of low clouds. We discuss both fundamental and implementation issues with this approach and suggest steps that could reduce uncertainty in the predicted low-cloud feedback. Recent studies using this approach predict that the tropical low-cloud feedback is positive mainly due to the observation that reflection of solar radiation by low clouds decreases as temperature increases, holding all other cloud-controlling factors fixed. The positive feedback from temperature is partially offset by a negative feedback from the tendency for the inversion strength to increase in a warming world, with other cloudcontrolling factors playing a smaller role. A consensus estimate from these studies for the contribution of tropical low clouds to the global mean cloud feedback is

show abstract

Section: I4 Imprecise Statistical Modelingmentioning

confidence: 92%

Low-Cloud Feedbacks from Cloud-Controlling Factors: A Review

et al. 2017

View full text Add to dashboard Cite

show abstract

“…Kawai and Teixeira [2010] extended this work and related the stability of the lower atmosphere to the thermodynamic characteristics and spatial inhomogeneity of low clouds. The importance of a jump in moist static energy across the inversion is also pointed out in studies using large-eddy simulations [Bretherton et al, 2013;Noda et al, 2014] and GCMs [Brient and Bony, 2013]. Therefore, improving the representation of the large-scale cloud environment is an important issue for better prediction of future climate change.…”

Section: Introductionmentioning

confidence: 92%

Intermodel variances of subtropical stratocumulus environments simulated in CMIP5 models

Noda

Satoh

2014

Geophysical Research Letters

View full text Add to dashboard Cite

This paper investigates simulation biases associated with the large-scale environments of subtropical marine stratocumulus (Sc) in present climate simulations from the Coupled Model Intercomparison Project Phase 5 models. Comparison of eight major variables that strongly control the Sc clouds, including jumps of temperature and vapor across the inversion layer, indicates that these models all have similar shortcomings, such as overestimation of sensible and latent surface fluxes. The differences among the biases of these major variables between the Sc regions were also evaluated. Of all Sc regions, the Namibian Sc region showed the largest biases. The modeled simulation skill of the annual variation of low cloud cover (LCC) increases when the correlation coefficient between LCC and lower atmospheric stability is higher. This paper reemphasizes the importance, suggested in previous studies, of an improved relationship between lower tropospheric stability and LCC if we are to better predict annual variations in subtropical LCC.

show abstract

“…This increases the entrainment of dry air into the boundary layer, which dries the cumulus layer drier and reduces cloud fraction. But rainfall puts a notable limit to such deepening, so that changes in cloudiness with global warming are overall small Bretherton et al 2013;Vogel et al 2016). …”

Section: Large-eddy Simulationsmentioning

confidence: 99%

Implications of Warm Rain in Shallow Cumulus and Congestus Clouds for Large-Scale Circulations

et al. 2017

View full text Add to dashboard Cite

Space-borne observations reveal that 20-40% of marine convective clouds below the freezing level produce rain. In this paper we speculate what the prevalence of warm rain might imply for convection and large-scale circulations over tropical oceans. We present results using a two-column radiative-convective model of hydrostatic, nonlinear flow on a non-rotating sphere, with parameterized convection and radiation, and review ongoing efforts in high-resolution modeling and observations of warm rain. The model experiments investigate the response of convection and circulation to sea surface temperature (SST) gradients between the columns and to changes in a parameter that controls the conversion of cloud condensate to rain. Convection over the cold ocean collapses to a shallow mode with tops near 850 hPa, but a congestus mode with tops near 600 hPa can develop at small SST differences when warm rain formation is more efficient. Here, interactive radiation and the response of the circulation are crucial: along with congestus a deeper moist layer develops, which leads to less low-level radiative cooling, a smaller buoyancy gradient between the columns, and therefore a weaker circulation and less subsidence over the cold ocean. The congestus mode is accompanied with more surface precipitation in the subsiding column and less surface precipitation in the deep convecting column. For the shallow mode over colder oceans, circulations also weaken with more efficient warm rain formation, but only marginally. Here, more warm rain reduces convective tops and the boundary layer depth-similar to Large-Eddy Simulation (LES) studies-which reduces the integrated buoyancy gradient. Elucidating the impact of warm rain can benefit from large-domain high-resolution simulations and observations. Parameterizations of warm rain may be constrained through collocated cloud and rain profiling from ground, and concurrent changes in convection and rain in subsiding and & Louise Nuijens

show abstract

Mechanisms of marine low cloud sensitivity to idealized climate perturbations: A single‐LES exploration extending the CGILS cases

Cited by 189 publications

References 54 publications

Low-Cloud Feedbacks from Cloud-Controlling Factors: A Review

Low-Cloud Feedbacks from Cloud-Controlling Factors: A Review

Intermodel variances of subtropical stratocumulus environments simulated in CMIP5 models

Implications of Warm Rain in Shallow Cumulus and Congestus Clouds for Large-Scale Circulations

Contact Info

Product

Resources

About