Atmospheric Physics study papers

In the Atmospheric Physics group  (formerly Clouds, Climate and Air Quality) we would like to discuss scientific papers that are relevant to the research done in our group.


7 Sept  Jason (KNMI) geostrophic wind

14 Sept Mariska de Koning: results on the importance of convection and cloudiness on momentum transport at Cabauw, using Whiffle's fine-scale forecasts

21 Sept Chiel

28 Sept Sukanta

5 Oct Kevin Helfer / Beatrice Saggiorato: convective momentum transport - first results or an interesting paper

12 Oct Stephan de Roode: LES results of the CONSTRAIN cold air outbreak

19 Oct Didier de Villiers / Louise: variability in subtropical wind profiles

26 Oct


TU Delft academic calender.

Peter Blossey of the University of Washington nicely summarizes a list of papers their group has discussed.

Ryu, Y.-H., J.-J. Baik, 2012: Quantitative analysis of factors contributing to urban heat island intensityJ. Appl. Meteor. Climatol.51, 842–854. Discussed by Patrick Schrijvers, 3 April 2013.

Harlim, J. and A. J. Majda, 2013: Test models for filtering with superparameterization. Multiscale Model. Simul., 11, 282-308.Discussed by Jesse Dorrestijn, 26 March 2013.

Lorenz, E., 1969: The predictability of a flow which possesses many scales of motionTellus21, 289-307. Discussed by Jerome Schalkwijk, 30 January 2013.

Hohenegger, C., and B. Stevens, 2012: Preconditioning deep convection with cumulus congestus. J. Atm. Sci., 70, 448- 464. Discussed by Jessica Loriaux, 12 December 2013.

Wood, R., 2007: Cancellation of aerosol indirect effects in marine stratocumulus through cloud thinning. J. Atm. Sci., 64, 2657-2669. Discussed by Johan van der Dussen, 28 November 2013.

Kuettner, J. P., 1971: Cloud bands in the earth's atmosphere. Observations and theory. Tellus, 23, 404-425. Discussed by Thomas Frederikse, 17 October 2012.

Lorenz, E. N., 1963: Deterministic Nonperiodic Flow. J. Atmos. Sci., 20, 130–141. To be discussed by Jesse Dorrestijn, 3 October 2012.

Brient, F., and S. Bony, 2012: Interpretation of the positive low-cloud feedback predicted by a climate model under global warming. Climate Dynamics, DOI: 10.1007/s00382-011-1279-7. To be discussed by Johan van der Dussen, 29 February 2012.

The response of low-level clouds to climate change has been identified as a major contributor to the uncertainty in climate sensitivity estimates among climate models. By analyzing the behaviour of low-level clouds in a hierarchy of models (coupled ocean-atmosphere model, atmospheric general circulation model, aqua-planet model, single-column model) using the same physical parameterizations, this study proposes an interpretation of the strong positive low-cloud feedback predicted by the IPSL-CM5A climate model under climate change. In a warmer climate, the model predicts an enhanced clear-sky radiative cooling, stronger surface turbulent fluxes, a deepening and a drying of the planetary boundary layer, and a decrease of tropical low-clouds in regimes of weak subsidence. We show that the decrease of low-level clouds critically depends on the change in the vertical advection of moist static energy from the free troposphere to the boundary-layer. This change is dominated by variations in the vertical gradient of moist static energy between the surface and the free troposphere just above the boundary-layer. In a warmer climate, the thermodynamical relationship of Clausius-Clapeyron increases this vertical gradient, and then the import by large-scale subsidence of low moist static energy and dry air into the boundary layer. This results in a decrease of the low-level cloudiness and in a weakening of the radiative cooling of the boundary layer by low-level clouds. The energetic framework proposed in this study might help to interpret inter-model differences in low-cloud feedbacks under climate change.


Dawe, J. T. and P. H. Austin, 2011: The influence of the cloud shell on tracer budget measurements of LES cloud entrainment. J. Atmos. Sci., 68, 2909–2920, doi:10.1175/2011JAS3658.1. To be discussed by Steef Böing, 1 February 2012.

Direct measurements of rates of entrainment into and detrainment from cumulus cloud cores obtained from LES model cloud fields produce values twice as large as those produced from tracer budget calculations. This difference can be explained by two effects: the presence of a shell of air around the cloud cores that is moister than the mean environment and air at the edge of the cloud core that is drier than the mean core, and the tendency for the mean tracer values of the entrained fluid to be greater than the mean tracer values of the cloud shell. Preferential entrainment of shell air that is moving upward faster than the mean shell creates strong vertical momentum fluxes into the cumulus cloud core, thereby making the assumption that cumulus cloud cores entrain fluid with zero vertical momentum incorrect. Variability in the properties of the moist cloud shell has strong impacts on entrainment values inferred from tracer budget calculations. These results indicate that the dynamics of the cloud shell should be included in parameterization of cumulus clouds used in general circulation models.


Neggers, R. A. J., M. Koehler, and A. C. M. Beljaars, 2009: A dual mass flux framework for boundary layer convection. Part I: Transport. J. Atmos. Sci., 66, 1465-1487. To be discussed by Arjan van Leeuwen, 23 November 2011.

This study considers the question of what is the least complex bulk mass flux framework that can still conceptually reproduce the smoothly varying coupling between the shallow convective cloud layer and the subcloud mixed layer. To this end, the model complexity of the classic single bulk mass flux scheme is enhanced. Inspired by recent large-eddy simulation results, the authors argue that two relatively minor but key conceptual modifications are already sufficient to achieve this goal: (i) retaining a dry transporting updraft in the moist limit and (ii) applying continuous updraft area partitioning to this dual mass flux (DualM) framework. The dry updraft represents all internal mixed layer updrafts that terminate near the mixed layer top, whereas the moist updraft represents all updrafts that condense and rise out of the mixed layer as buoyant cumulus clouds. The continuous area partitioning between the dry and moist updraft is a function of moist convective inhibition above the mixed layer top. Updraft initialization is a function of the updraft area fraction and is therefore consistent with the updraft definition. It is argued that the model complexity thus enhanced is sufficient to allow reproduction of various phenomena involved in the cloud– subcloud coupling, namely (i) dry countergradient transport within the mixed layer that is independent of the moist updraft, (ii) soft triggering of moist convective flux throughout the boundary layer, and (iii) a smooth response to smoothly varying forcings, including the reproduction of gradual transitions to and from shallow cumulus convection.

Seifert, A, L. Nuijens, and B. Stevens, 2011: Turbulence effects on warm-rain autoconversion in precipitating shallow convection. Quart. J. Roy. Meteor. Soc., 136, 1753-1762. To be discussed by Vincent Perrin, 9 November 2011.

A parametrization of the rain formation in warm clouds is developed which includes the effects of turbulence on the collision rate of droplets in a cloud. It is shown that already moderate turbulence with dissipation rates of 400 cm2s−3 can lead to a significant speed-up of the rain formation corresponding to an increase in the autoconversion rate by a factor of 4–6 depending on the size of the droplets. Large- eddy simulations of trade wind cumuli also produce a significant enhancement of rain formation through turbulence effects on cloud microphysics. In small cumulus clouds, the highest turbulent dissipation rates occur near cloud-top, which is also the decisive region of the cloud for the initial rain formation.

Bellon, G., and B. Stevens, 2011: Using the sensitivity of large-eddy simulations to evaluate atmospheric boundary-layer models. Submitted to the J. Atmos. Sci. To be discussed by Sara dal Gesso, 14 September 2011.

A simple framework to study the sensitivity of Atmospheric Boundary Layer (ABL) models to the large-scale conditions and forcings is introduced. This framework minimizes the number of parameters necessary to describe the large-scale conditions, subsidence, and radiation. Using this framework, the sensitivity of the stationary Atmospheric Boundary Layer (ABL) to the large-scale boundary conditions (underlying Sea Surface Temperature (SST) and overlying humidity and temperature in the free troposphere) is investi- gated in Large-Eddy Simulations (LESs). For increasing SST or decreasing free-tropospheric temperature, the LES exhibits a transition from a cloud-free, well-mixed ABL stationary state, through a cloudy, well-mixed stationary state and a stable shallow-cumulus stationary state, to an unstable regime with a deepening shallow-cumulus layer. For a warm SST, when increas- ing free-tropospheric humidity, the LES exhibits a transition from a stable shallow-cumulus stationary state, through a stable cumulus-under-stratus sta- tionary state, to an unstable regime with a deepening, cumulus-under-stratus layer for warm SSTs. For a cool SST, when increasing the free-tropospheric humidity, the LES stationary state exhibits a transition from a cloud-free, well-mixed ABL regime, through a well-mixed cumulus-capped regime, to a stratus-capped regime with a decoupling between the subcloud and cloud layers.


Mapes, B. and R. Neale, 2011: Parameterizing convective organization to escape the entrainment dilemma. J. Adv. Model. Earth Syst., 3, Art. M06004, 20 pp. (discussed by Steef Boing, 1 September 2011)

A new variable is introduced for convection schemes that apply a lateral entrainment parameterization. This quantity is called 'Organization' or Org, and is meant to reflect the rectified effects of subgrid scale structure in meteorological fields.


Lenderink, G. and E. van Meijgaard, 2008: Increase in hourly precipitation extremes beyond expectations from temperature changes. Nature Geosc., 1, 511-514 (discussed by Jessica Loriaux, Jun, 2011)

Haerter, J. O. and P. Berg, 2009: Unexpected rise in extreme precipitation caused by a shift in rain typeNature Geosc., 2, 372-373, and a reply by Lenderink and van Meijgaard.

Lenderink and van Meijgaard study an hourly time series of precipitation data obtained at De Bilt, The Netherlands. They observed an exponential increase of heavy precipitation with temperature, with a coefficient close to that of the Clausius– Clapeyron relation for lower temperatures, whereas for higher temperatures they found super‑Clausius–Clapeyron behaviour. Haerter and Berg argue that the super‑Clausius– Clapeyron scaling for hourly, but not for daily, precipitation arises because of the superposition of two facts: (1) the dramatically different timescales between large‑scale and convective precipitation and (2) the dominance of convective precipitation for high temperatures and the dominance of large‑scale precipitation for cool temperatures. The letter, and the two replies will be discussed by Jessica Loriaux, 1 June 2011.


Fletcher, J. K., and C. S. Bretherton, 2011: Evaluating boundary-layer based mass flux closures using cloud-resolving model simulations of deep convection. AMS., preliminary accepted (to be discussed by Steef Boing, 4 May 2011).

We use high-resolution 3-dimensional cloud resolving model simulations of deep cumulus convection under a wide range of large-scale forcings to evaluate a mass flux closure based on boundary layer convective inhibition (CIN) that has previously been applied in parameterizations of shallow cumulus convection. With minor modifications, it is also found to perform well for deep oceanic and continental cumulus convection, and matches simulated cloud base mass flux much better than a closure based only on the boundary layer convective velocity scale. CIN closure maintains an important feedback between cumulus base mass flux, compensating subsidence, and CIN that keeps the boundary layer top close to cloud base. For deep convection, the proposed CIN closure requires prediction of a boundary-layer mean TKE and a horizontal moisture variance, both of which are strongly correlated with precipitation. For our cases, CIN closure predicts cloud base mass flux in deep convective environments as well as the best possible bulk entraining-CAPE closure, but unlike the latter, CIN closure also works well for shallow cumulus convection without retuning of parameters.


Harman, I. N., and S. E. Belcher, 2006: The surface energy balance and boundary layer over urban street canyons. Q. J. R. Meteor. Soc., 132, 2749-2768 (to be discussed by Stephan de Roode, 20 April 2011).

A model is developed for the energy balance of an urban area, represented as a sequence of two-dimensional street canyons. The model incorporates a novel formulation for the sensible-heat flux, that has previously been validated against wind tunnel models, and a formulation for radiation that includes multiple reflections and shadowing. This energy balance model is coupled to a model for the atmospheric boundary layer. Results are analysed to establish how the physical processes combine to produce the observed features of urban climate, and to establish the roles of building form and fabric on the urban modification to climate.


Hanna, S. R., and co-authors, 2006: Dispersion in downtown Manhattan. An Application of Five Computational Fluid Dynamics Models. Bull. Amer. Met. Soc.87, 1713-1726 (to be discussed by Patrick Schrijvers).

Using the same urban atmospheric boundary layer scenario in New York City, the five CFD models produce similar wind flow patterns, as well as good agreement with winds observed during a field experiment.


Shaw, R. A., 2003: Particle-Turbulence Interactions in Atmospheric Clouds. Annu. Rev. Fluid Mech., 35, 183-227 (to be discussed by Tanima Chatterjee, Sections 1, 2, 3.1, 4.1, 5.3, 6.1,  6.2 and 8.

It is expected, therefore, that fine-scale turbulence is of direct importance to the evolution of, for example, the droplet size distribution in a cloud. In general, there are two levels of interaction that are considered in this review: (a) the growth of cloud droplets by condensation and (b) the growth of large drops through the collision and coalescence of cloud droplets. Recent research suggests that the influence of fine-scale turbulence on the condensation process may be limited, although several possible mechanisms have not been studied in detail in the laboratory or the field. There is a growing consensus, however, that the collision rate and collision efficiency of cloud droplets can be increased by turbulence-particle interactions. Adding strength to this notion is the growing experimental evidence for droplet clustering at centimeter scales and below, most likely due to strong fluid accelerations in turbulent clouds. Both types of interaction, condensation and collision-coalescence, remain open areas of research with many possible implications for the physics of atmospheric clouds.


Bjorn Stevens, 2006: Bulk boundary-layer concepts for simplified models of tropical dynamics. Theor. Comput. Fluid. Dyn. (to be discussed by Sara dal Gesso, 9 February 2011 and Jerome Schalkwijk, 23 February 2011).

We review bulk representations of tropical and subtropical maritime atmospheric boundary layers. Three types of bulk representations are studied in detail: stratocumulus toppedmixed layers, trade-wind layers, and sub-cloud mixed layers. Through the development of a consistent description of these disparate regimes, connections among their varied representations are emphasized, as well as their relation to regions of deeper convection. New results relating to the equilibrium mass flux and cloud fraction in the trade winds; the ability of bulk models to represent qualitatively major cloud regimes; and the relationship amongst different bulk representations of the surface layer are presented. Throughout we emphasize the identification of consistent and physically based mixing and cloud regime rules for use in intermediate complexity models of the tropical climate, which in turn can be used to study cloud and dynamical interactions on larger scales.

Plant, R. S., and G. C. Craig, 2008: A Stochastic Parameterization for Deep Convection Based on Equilibrium Statistic, J. Atm. Sci., 65, 1650-1672 (to be discussed by Jesse Dorrestijn, 12 January 2011) .

A stochastic parameterization scheme for deep convection is described, suitable for use in both climate and NWP models. Theoretical arguments and the results of cloud-resolving models are discussed in order to motivate the form of the scheme. In the deterministic limit, it tends to a spectrum of entraining/detraining plumes and is similar to other current parameterizations. The stochastic variability describes the local fluctuations about a large-scale equilibrium state. Plumes are drawn at random from a probability distri- bution function (PDF) that defines the chance of finding a plume of given cloud-base mass flux within each model grid box. The normalization of the PDF is given by the ensemble-mean mass flux, and this is computed with a CAPE closure method. The characteristics of each plume produced are determined using an adaptation of the plume model from the Kain–Fritsch parameterization. Initial tests in the single-column version of the Unified Model verify that the scheme is effective in producing the desired distributions of convective variability without adversely affecting the mean state.


Tompkins, A., 2001: Organization of tropical convection in low vertical wind shears: The role of cold pools, J. Atm. Sci., 58, 1650-1672 (to be discussed by Emily Jones, 15 December 2010) .

An investigation is conducted to document the role convectively generated cold pools play in determining the spatial organization of tropical deep convection. Using a high-resolution cloud-resolving model, the evolution of cold pools produced by deep convection is examined, in the situation of limited large-scale wind shear, and a homogeneous underlying sea surface temperature.


Bretherton et al., 2010, Slow manifolds and multiple equilibria in stratocumulus-capped boundary layers, J. of Adv. in Modeling Earth Systems - Discussion (JAMES-D) (to be discussed by Johan van der Dussen, 1 December 2010) .

Slow-manifold analysis is applied to mixed-layer model and large-eddy simulations of an idealized nocturnal stratocumulus-capped boundary layer. Both models are found to have multiple equilibria; depending on the initial inversion height, the simulations slowly evolve toward a shallow thin-cloud boundary layer or a deep, well-mixed thick cloud boundary layer.



Romps, D., 2010: A direct measure of entrainment. J. Atmos. Sci., 67, (to be discussed by Steef Boing, 20 November 2010).

A method is introduced for directly measuring convective entrainment and detrainment in a cloud resolving simulation. This technique is used to quantify the errors in the entrainment and detrainment estimates obtained using the standard bulk-plume method.


Pincus, R, H. W. Barker and J.-J. Morcrette, 2003: A fast, flexible, approximate technique for computing radiative transfer in inhomogeneous cloud fields. J. Geo. Res., 108 (discussed by Stephan de Roode, 3 November 2010)

Radiative transfer calculations are numerically expensive as the radiation needs to be computed in multiple wavebands. This paper introduces a new concept (Monte Carlo Independent Pixel Approximation) that is currently implemented in quite some large-scale models. The basic idea is that radiation is not calculated in every waveband anymore, but only in a limited number of randomly sampled wavebands, in addition to a limited number of subgrid columns with different thermodynamic states. This approach therefore takes into account horizontal inhomogeneity of clouds and its associated plane-parallell albedo bias problem.


Stevens, B, 2007: On the Growth of Layers of Nonprecipitating Cumulus Convection. J. Atmos. Sci., 64, 2916–2931. (17 February 2010, discussed by Pier Siebesma).

A prototype problem of a nonprecipitating convective layer growing into a layer of uniform stratification and exponentially decreasing humidity is introduced to study the mechanism by which the cumulus-topped boundary layer grows.


Jarecka, D., W.W. Grabowski, and H. Pawlowska, 2009: Modeling of subgrid-scale mixing in Large-Eddy Simulation of shallow convection. J. Atmos. Sci., 66, 2125–2133. (27 January 2010, discussed by Stephan de Roode).

If liquid water is advected into a neighbouring unsaturated grid box this water will be evaporated. This results in spurious evaporative cooling that will lower the buoyancy of this grid box. This paper discusses a possible solution to this numerical problem.


Jonker, H. J. J., T. Heus and P. P. Sullivan, 2008: A refined view of vertical mass transport by cumulus convection. Geoph. Res. Lett.,  35, doi:10.1029/2007GL032606. (16 December 2009, discussed by Susan Pesman).

In the classical view it is assumed that the compensating downward motions induced by cumulus convection occur in a large region outside the clouds.  This paper shows the a significant fraction of the downward motion takes place in the vicinity of the cloud boundaries.


Schubert,  W. H., J. S. Wakefield,  E. J. Steiner, and S. K. Cox, 1979: Marine stratocumulus convection. Part I: Governing equations and horizontally homogeneous solutions. J. Atmos. Sci., 36, 1286-1307 (26 November 2009, discussed by Melchior van Wessem)

This is a classical paper that uses the mixed layer model to compute steady solutions of stratocumulus clouds.

Nieuwstadt, F. T. M, and R. A. Brost, 1986: The decay of convective turbulence. J. Atmos. Sci., 43, 532–546, and Sorbjan, Z., 1997: Decay of convective turbulence revisited. Bound.-Lay. Meteor., 82, 501-515. (November 2009, discussed by Robert ten Driel).

Typically one is inclined to study prototype atmospheric boundary layers like the free convective one, stably stratified or stratocumulus or cumulus. The two papers discuss the evolution of the turbulence field during a transition from convectively driven to stably stratified.


Federovich, E., R. Conzemius, and D. Mironov, 2004: Convective entrainment into a shear-free, linearly stratified atmosphere: Bulk models reevaluated through large eddy simulations. J. Atmos. Sci., 61, 281–295 (October 2009, discussed by Harm Jonker).

Entrainment of air from just above the inversion by convective thermals leads to a growth of the atmospheric boundary layer height. This paper presents non-dimensional parameters relevant to the entrainment process and reevaluates entrainment rate results from models and laboratory results.


Randall, D.A., 1987: Turbulent Fluxes of Liquid Water and Buoyancy in Partly Cloudy Layers. J. Atmos. Sci., 44, 850–858 (September 2009, discussed by Stephan de Roode).

The mass flux approach is used to calculate turbulent fluxes in stratocumulus and cumulus. The effect of cloud fraction smaller than unity on the buoyancy flux is investigated. Using given values for the heat and moisture fluxes it is found that the buoyancy flux will become larger if the cloud fraction becomes smaller. This is explained from the fact that condensation may occur in the saturated updraft but not in the downdraft.


Muller, C.J., L. E. Back, P. A. O'Gorman, and K. A. Emanuel, 2009: A model for the relationship between tropical precipitation and column water vapor. Geoph. Res. Lett., 36, L16804, doi:10.1029/2009/GL039667 ( 9 September 2009, discussed by Steef Boïng).

This paper shows that by simply assuming two independent Gaussian distributions of the WVP in the subcloud and cloud layers, and using a simple linear parameterization for the precipitation, yields results for the precipitation and its variance that are similar to observations.