Cloud Droplet Concentration Research Articles

Regional climatic effects according to different estimations of biogenic volatile organic compounds during the asian summer monsoon

A series of 60-year numerical experiments starting from 1851 was conducted using a global climate model coupled with an aerosol-cloud-radiation model to investigate the response of the Asian summer monsoon to variations in the secondary organic aerosol (SOA) flux induced by two different estimations of biogenic volatile organic compound (BVOC) emissions. One estimation was obtained from a pre-existing archive and the other was generated by a next-generation model (the Model of Emissions of Gases and Aerosols from Nature, MEGAN). The use of MEGAN resulted in an overall increase of the SOA production through a higher rate of gasto-particle conversion of BVOCs. Consequently, the atmospheric loading of organic carbon (OC) increased due to the contribution of SOA to OC aerosol. The increase of atmospheric OC aerosols was prominent in particular in the Indian subcontinent and Indochina Peninsula (IP) during the pre- and early-monsoon periods because the terrestrial biosphere is the major source of BVOC emissions and the atmospheric aerosol concentration diminishes rapidly with the arrival of monsoon rainfall. As the number of atmospheric OC particles increased, the number concentrations of cloud droplets increased, but their size decreased. These changes represent a combination of aerosol-cloud interactions that were favorable to rainfall suppression. However, the modeled precipitation was slightly enhanced in May over the oceans that surround the Indian subcontinent and IP. Further analysis revealed that a compensating updraft in the surrounding oceans was induced by the thermally-driven downdraft in the IP, which was a result of surface cooling associated with direct OC aerosol radiative forcing, and was able to surpass the aerosolcloud interactions. The co-existence of oceanic ascending motion with the maximum convective available potential energy was also found to be crucial for rainfall formation. Although the model produced statistically significant rainfall changes with locally organized patterns, the suggested pathways should be considered guardedly because in the simulation results, 1) the BVOC-induced aerosol direct effect was marginal; 2) cloud-aerosol interactions were modeldependent; and 3) Asian summer monsoons were biased to a nonnegligible extent.

Inversion of droplet aerosol analyzer data for long-term aerosol–cloud interaction measurements

Abstract. The droplet aerosol analyzer (DAA) was developed to study the influence of aerosol properties on clouds. It measures the ambient particle size of individual droplets and interstitial particles, the size of the dry (residual) particles after the evaporation of water vapor and the number concentration of the dry (residual) particles. A method was developed for the evaluation of DAA data to obtain the three-parameter data set: ambient particle diameter, dry (residual) particle diameter and number concentration. First results from in-cloud measurements performed on the summit of Mt. Brocken in Germany are presented. Various aspects of the cloud–aerosol data set are presented, such as the number concentration of interstitial particles and cloud droplets, the dry residue particle size distribution, droplet size distributions, scavenging ratios due to cloud droplet formation and size-dependent solute concentrations. This data set makes it possible to study clouds and the influence of the aerosol population on clouds.

Aircraft observations of liquid and ice in midlatitude mixed-phase clouds

This paper reports airborne measurements of midlatitude altostratus clouds observed over Zhengzhou, Henan Province, China on 3 March 2007. The case demonstrates mixed-phase conditions at altitudes from 3200 to 4600 m (0°C to −7.6°C), with liquid water content ranging from 0.01 to 0.09 g m−3. In the observed mixed-phase cloud, liquid water content exhibited a bimodal distribution, whereas the maximum ice particle concentration was located in the middle part of the cloud. The liquid and ice particle data showed significant horizontal variability on the scale of a few hundred meters. The cloud droplet concentration varied greatly over the horizontal sampling area. There was an inverse relationship between the cloud droplet concentration and ice particle concentration.

Assessment of cloud condensation nucleus activation of urban aerosol particles with different hygroscopicity and the application to the cloud parcel model

Size-resolved measurements of the ratios of cloud condensation nuclei (CCN) to condensation nuclei for particles with different hygroscopic growth factors (g) and distributions of g at 85% relative humidity were performed for urban aerosols over Nagoya, Japan. The CCN efficiency spectra of less hygroscopic particles (g of 1.0 and 1.1) were very different from those of more hygroscopic particles (g of 1.25 and 1.4). While the differences between the CCN activation diameters predicted from g (dact,g85) and those measured (dact,CCN) were within 12% for more hygroscopic particles, the differences were larger (16%–41%) for less hygroscopic particles. Possible causes of this included surface tension reduction, the dependence of κ on the concentration of the solution, the existence of sparingly soluble materials, and asphericity of particles. The number concentrations of CCN (NCCN) and cloud droplets (Ncd) and the effective radius of cloud droplets (Reff) were estimated from the distributions of g using a cloud parcel model. The influences of the differences between dact,g85 and dact,CCN and the existence of CCN-inactive particles on the model assessment were small. With high updraft velocity, incorporating both less and more hygroscopic particles into the model led to substantial increases in NCCN and Ncd and a decrease in Reff as compared to the hypothetical cases that only more hygroscopic particles were present. The results indicated that less hygroscopic particles significantly contribute to cloud droplet formation and assessments of g distributions are useful in this regard.

A PDF-Based Microphysics Parameterization for Shallow Cumulus Clouds

Abstract Unbiased calculations of microphysical process rates such as autoconversion and accretion in mesoscale numerical weather prediction models require that subgrid-scale (SGS) variability over the model grid volume be taken into account. This variability can be expressed as probability distribution functions (PDFs) of microphysical variables. Using dynamically balanced large-eddy simulation (LES) model results from a case of marine trade cumulus, the authors develop PDFs of the cloud water, droplet concentration, and rainwater variables (qc, Nc, and qr). Both 1D and 2D joint PDFs (JPDFs) are presented. The authors demonstrate that accounting for the JPDFs results in more accurate process rates for a regional-model grid size. Bias in autoconversion and accretion rates are presented, assuming different formulations of the JPDFs. Approximating the 2D PDF using a product of individual 1D PDFs overestimates the autoconversion rates by an order of magnitude, whereas neglecting the SGS variability altogether results in a drastic underestimate of the grid-mean autoconversion rate. PDF assumptions have a much smaller impact on accretion, largely because of the near-linear dependence of the variables in the accretion rate formula and the relatively weak correlation between qc and qr over the small LES grid volumes. The latter is attributed to the spatial decorrelation in the vertical between the two fields. Although the full PDFs are both height and time dependent, results suggest that fixed-in-time and fixed-in-height PDFs give an acceptable level of accuracy, especially for the crucial autoconversion calculation.

Particle size spectra and possible mechanisms of high ice concentration in nimbostratus over Hebei Province, China

By employing the three-aircraft measurements combined with Radar and satellite imageries, microphysical structures of a nimbostratus cloud caused by a westerly trough in Zhangjiakou City, Hebei Province on May 1, 2009 are analyzed in this paper, focusing on vertical distribution of PSD (particle size distribution) and the 2D imagery at a variety of altitudes and temperatures. PSD generally appeared to conform to an exponential size distribution, with well-correlated linear fits between the log of the number concentration and particle diameter. Similar to previous studies, analyses of PSD parameters N0 and λ of empirical function Ns=N0exp(−Dλ) show that particle growth falls into three stages according to spectral trajectory. The positive shift in both N0 and λ at temperatures higher than −8°C in our study was likely caused by extension of supercooled droplet spectra, and according to earlier studies, the effect of large droplets on ice concentration can also be proved by seeking correlations between ice particle concentration and the concentration of cloud droplets exceeding a certain diameter. However, 2D imageries showed that only a few (<10%) ice particles were pristine in the −3 to −10°C temperature range. The large number of unidentifiable ice particles could have originated from shattering of larger drops during freezing in fall. In the region of −10 to −15°C, the secondary ice production mechanism may be the dendrite crystal–crystal collision breakup. Moreover, other mechanisms including deposition growth of small ice particles within the convective turrets near cloud top and activation of anthropogenic pollutant such as mineral dust, biological, and oxidized organic aerosol particles may also affect ice particle concentrations.

CCN and Vertical Velocity Influences on Droplet Concentrations and Supersaturations in Clean and Polluted Stratus Clouds

Abstract Cloud microphysics and cloud condensation nuclei (CCN) measurements from two marine stratus cloud projects are presented and analyzed. Results show that the increase of cloud droplet concentrations Nc with CCN concentrations NCCN rolls off for NCCN at 1% supersaturation (S)N1% above 400 cm−3. Moreover, at such high concentrations Nc was not so well correlated with NCCN but tended to be more closely related to vertical velocity W or variations of W (σw). This changeover from predominate Nc dependence on NCCN to Nc dependence on W or σw is due to the higher slope k of CCN spectra at lower S, which is made more relevant by the lower cloud S that is forced by higher NCCN. Higher k makes greater influence of W or σw variations than NCCN variations on Nc. This changeover at high NCCN thus seems to limit the indirect aerosol effect (IAE). On the other hand, in clean-air stratus cloud S often exceeded 1% and decreased to slightly less than 0.1% in polluted conditions. This means that smaller CCN [those with higher critical S (Sc)], which are generally more numerous than larger CCN (lower Sc), are capable of producing stratus cloud droplets, especially when they are advected into clean marine air masses where they can induce IAE. Positive correlations between turbulence σw and NCCN are attributed to greater differential latent heat exchange of smaller more numerous cloud droplets that evaporate more readily. Such apparent CCN influences on cloud dynamics tend to support trends that oppose conventional IAE, that is, less rather than greater cloudiness in polluted environments.

Simulation of aerosol effects on orographic clouds and precipitation using WRF model with a detailed bin microphysics scheme

AbstractThe effects on orographic clouds and precipitation of aerosol loading have been investigated by simulating an idealized mixed‐phase orographic cloud using the Weather Research Forecast (WRF) mesoscale model coupled with a detailed bin microphysics scheme. The results show that the total precipitation amount is reduced by 23.4% with increasing aerosol loading on the orographic clouds. Moreover, increasing aerosol loading will increase the number concentration of cloud droplets in small size range (&lt;19.84 µm in diameter) and lead to a decrease in the peak diameter from 12.5 to 9.92 µm.

Developments in the CSU-RAMS Aerosol Model: Emissions, Nucleation, Regeneration, Deposition, and Radiation

AbstractThe Colorado State University (CSU) Regional Atmospheric Modeling System (RAMS) has undergone development focused on improving the treatment of aerosols in the microphysics model, with the goal of examining the impacts of aerosol characteristics, scavenging, and regeneration processes, among others, on precipitation processes in clouds ranging from stratocumulus to deep convection and mixed-phase orographic clouds. Improvements in the representation of aerosols allow for more comprehensive studies of aerosol effects on cloud systems across scales. In RAMS there are now sub- and supermicrometer modes of sulfate, mineral dust, sea salt, and regenerated aerosol. All aerosol species can compete for cloud droplet nucleation, and they are regenerated via hydrometeor evaporation. A newly applied heterogeneous ice nuclei parameterization accounts for deposition nucleation and condensation and immersion freezing of aerosols greater than 0.5-μm diameter. There are also schemes for trimodal sea salt emissions and bimodal dust lofting that are functions of wind speed and surface properties. Aerosol wet and dry deposition accounts for collection by falling hydrometeors as well as gravitational settling of aerosols on water, soil, and vegetation. Aerosol radiative effects are parameterized via the Mie theory. An examination of the simulated impact of aerosol characteristics, sources, and sinks reveals mixed sensitivity among cloud types. For example, reduced aerosol solubility has little impact on deep convection since supersaturations are large and nearly all accumulation-mode aerosols activate. In contrast, reduced solubility results in reduced aerosol activation in precipitating stratocumulus. This leads to lower cloud droplet concentration, larger droplet size, and more efficient warm rain processes.

Large contribution of natural aerosols to uncertainty in indirect forcing

The effect of anthropogenic aerosols on cloud droplet concentrations and radiative properties is the source of one of the largest uncertainties in the radiative forcing of climate over the industrial period. This uncertainty affects our ability to estimate how sensitive the climate is to greenhouse gas emissions. Here we perform a sensitivity analysis on a global model to quantify the uncertainty in cloud radiative forcing over the industrial period caused by uncertainties in aerosol emissions and processes. Our results show that 45 per cent of the variance of aerosol forcing since about 1750 arises from uncertainties in natural emissions of volcanic sulphur dioxide, marine dimethylsulphide, biogenic volatile organic carbon, biomass burning and sea spray. Only 34 per cent of the variance is associated with anthropogenic emissions. The results point to the importance of understanding pristine pre-industrial-like environments, with natural aerosols only, and suggest that improved measurements and evaluation of simulated aerosols in polluted present-day conditions will not necessarily result in commensurate reductions in the uncertainty of forcing estimates.

Sensitivity study of the influence of cloud droplet concentration on hail suppression effectiveness

A cloud-resolving mesoscale model with a two-moment microphysical scheme has been used. The software package for cloud seeding and two categories of precipitation elements (graupel and frozen raindrops) are incorporated in the model. The aim of this study was to investigate the impact of cloud droplet concentration on hail suppression effectiveness. The concentration level of cloud droplets is prescribed in the model. We performed sensitivity tests of precipitation amounts (rain and hail) on the cloud droplet concentration in unseeded and seeded cases. We demonstrated for the unseeded case that increasing the concentration of cloud droplets created a reduction in rain accumulation, while the amount of hail accumulation increased. It is necessary to understand whether natural diversity in the cloud droplet concentration can affect the effectiveness of hail suppression. For operational cloud seeding activities, it would be helpful to determine whether it is possible to suppress hail if we know the optimal level of concentration for cloud droplets. Our study showed that hail suppression effectiveness had the greatest influence on lowering cloud droplet concentration levels; suppression effectiveness decreased as the cloud droplet concentration increased.

In situ observations of supercooled liquid clouds over the Southern Ocean during the HIAPER Pole‐to‐Pole Observation campaigns

Clouds over the Southern Ocean exist in a pristine environment that results in unique microphysical properties. However, in situ observations of these clouds are rare, and the dominant precipitation processes are unknown. Uncertainties in their life cycles and radiative properties make them interesting from a weather and climate perspective. Data from the standard cloud physics payload during the High‐performance Instrumented Airborne Platform for Environmental Research (HIAPER) Pole‐to‐Pole Observations global transects provide a unique snapshot the nature of low‐level clouds in the Southern Ocean. High quantities of supercooled liquid water (up to 0.47gm−3) were observed in clouds as cold as −22°C during two flights in different seasons and different meteorological conditions, supporting climatologies inferred from satellite observations. Cloud droplet concentrations were calculated from mean droplet size and liquid water concentrations, and were in the range of 30–120cm−3, which is fairly typical for the pristine Southern Ocean environment. Ice in nonprecipitating or lightly precipitating clouds was found to be rare, while drizzle drops with diameter greater than 100μm formed through warm rain processes were widespread. Large, pristine crystals were commonly seen in very low concentrations below cloud base.

Modeling aerosol activation in a tropical, orographic, island setting: Sensitivity tests and comparison with observations

The aerosol, updraft and cloud droplet observations from the 2011 Dominica Experiment (DOMEX) field campaign provide an interesting opportunity to investigate the process of cloud droplet activation in a tropical, orographic, convective setting. This study involves adiabatic parcel model simulations with a state-of-the-art parameterization of droplet activation, which we run with aerosol size distributions and updraft velocities based on DOMEX data. We compare the cloud droplet concentrations predicted by the parameterization with the observations from DOMEX, and run various sensitivity tests to changes in model inputs on the order of their uncertainty, in order to gain insights into what factors are most important in determining the aerosol activation fraction in this setting. Our control simulations overestimated the observed droplet concentrations, especially for the days with strong trade winds, but in most cases these discrepancies could be eliminated by realistic changes in our assumptions. The remaining error could be the result of entrainment of sub-saturated air, precipitation, or advection of pre-existing clouds from upwind. We found strong sensitivities to the mean updraft velocity and to the size distribution and composition of particles in the Aitken mode, the smallest mode including particles below 100nm. The Aitken mode accounted for 42% to 68% of the simulated droplet concentration in our control simulations, and simulations excluding the Aitken mode underestimated the observed droplet concentrations under realistic assumptions. Droplets from the Aitken mode dominated the changes in the simulated droplet concentrations in our sensitivity tests. The precision of our simulations, and our ability to constrain the role of the Aitken mode, were limited by our lack of knowledge of the composition and size distribution of Aitken mode particles, highlighting the importance of measuring these variables in field campaigns in similar settings.

Experimental investigations of the effect of cloud-medium modification by salt powders

The results of experimental investigations into the action of polydispersion salt powders on model cloud media are presented. The results of experiments show a considerable positive effect of the modification of convective clouds by salt powders in order to obtain additional precipitation. The introduction of polydispersion salt powder into a forming cloud medium leads to the appearance of large cloud droplets and to the droplet-spectrum broadening. This result is a positive factor for the stimulation of coagulation processes and further precipitation formation. No “overseeding” phenomenon (when, instead of the enlargement of droplets, their sizes decrease and the concentration of cloud droplets increases) is observed at rather high mass concentrations of the introduced powder.

A comparative study of the response of modeled non-drizzling stratocumulus to meteorological and aerosol perturbations

Abstract. The impact of changes in aerosol and cloud droplet concentration (Na and Nd) on the radiative forcing of stratocumulus-topped boundary layers (STBLs) has been widely studied. How these impacts compare to those due to variations in meteorological context has not been investigated in a systematic fashion for non-drizzling overcast stratocumulus. In this study we examine the impact of observed variations in meteorological context and aerosol state on daytime, non-drizzling overcast stratiform evolution, and determine how resulting changes in cloud properties compare. Using large-eddy simulation (LES) we create a model base case of daytime southeast Pacific coastal stratocumulus, spanning a portion of the diurnal cycle (early morning to near noon) and constrained by observations taken during the VOCALS (VAMOS Ocean-Atmosphere-Land Study) field campaign. We perturb aerosol and meteorological properties around this base case to investigate the stratocumulus response. We determine perturbations in the cloud top jumps in potential temperature θ and total water mixing ratio qt from ECMWF Re-analysis Interim data, and use a set of Nd values spanning the observable range. To determine the cloud response to these meteorological and aerosol perturbations, we compute changes in liquid water path (LWP), bulk optical depth (τ) and cloud radiative forcing (CRF). We find that realistic variations in the thermodynamic jump properties can elicit a response in the cloud properties of τ and shortwave (SW) CRF that are on the same order of magnitude as the response found due to realistic changes in aerosol state (i.e Nd). In response to increases in Nd, the cloud layer in the base case thinned due to increases in evaporative cooling and entrainment rate. This cloud thinning somewhat mitigates the increase in τ resulting from increases in Nd. On the other hand, variations in θ and qt jumps did not substantially modify Nd. The cloud layer thickens in response to an increase in the θ jump and thins in response to an increase in the qt jump, both resulting in a τ and SW CRF response comparable to those found from perturbations in Nd. Longwave CRF was not substantially altered by the perturbations we tested. We find that realistic variations in meteorological context can elicit a response in CRF and τ on the same order of magnitude as, and at times larger than, that response found due to realistic changes in aerosol state. We estimate the limits on variability of cloud top jump properties required for accurate observation of aerosol SW radiative impacts on stratocumulus, and find strict constraints: less than 1 K and 1 g kg−1 in the early morning hours, and order 0.1 K and 0.1 g kg−1 close to solar noon. These constraints suggest that accurately observing aerosol radiative impacts in stratocumulus may be challenging as co-variation of meteorological properties may obfuscate aerosol-cloud interactions.

Long-term measurements of cloud droplet concentrations and aerosol–cloud interactions in continental boundary layer clouds

The effects of aerosol on cloud droplet effective radius (Reff), cloud optical thickness and cloud droplet number concentration (Nd) are analysed both from long-term direct ground-based in situ measurements conducted at the Puijo measurement station in Eastern Finland and from the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument onboard the Terra and Aqua satellites. The mean in situ Nd during the period of study was 217 cm−3, while the MODIS-based Nd was 171 cm−3. The absolute values, and the dependence of both Nd observations on the measured aerosol number concentration in the accumulation mode (Nacc), are quite similar. In both data sets Nd is clearly dependent on Nacc, for Nacc values lower than approximately 450 cm−3. Also, the values of the aerosol–cloud-interaction parameter [ACI=(1/3)*d ln(Nd)/d ln(Nacc)] are quite similar for Nacc<400 cm−3 with values of 0.16 and 0.14 from in situ and MODIS measurements, respectively. With higher Nacc (>450 cm−3) Nd increases only slowly. Similarly, the effect of aerosol on MODIS-retrieved Reff is visible only at low Nacc values. In a sub set of data, the cloud and aerosol properties were measured simultaneously. For that data the comparison between MODIS-derived Nd and directly measured Nd, or the cloud droplet number concentration estimated from Nacc values (Nd,p), shows a correlation, which is greatly improved after careful screening using a ceilometer to make sure that only single cloud layers existed. This suggests that such determination of the number of cloud layers is very important when trying to match ground-based measurements to MODIS measurements.

Implementation of a Silver Iodide Cloud-Seeding Parameterization in WRF. Part I: Model Description and Idealized 2D Sensitivity Tests

AbstractA silver iodide (AgI) cloud-seeding parameterization has been implemented into the Thompson microphysics scheme of the Weather Research and Forecasting model to investigate glaciogenic cloud-seeding effects. The sensitivity of the parameterization to meteorological conditions, cloud properties, and seeding rates was examined by simulating two-dimensional idealized moist flow over a bell-shaped mountain. The results verified that this parameterization can reasonably simulate the physical processes of cloud seeding with the limitations of the constant cloud droplet concentration assumed in the scheme and the two-dimensional model setup. The results showed the following: 1) Deposition was the dominant nucleation mode of AgI from simulated aircraft seeding, whereas immersion freezing was the most active mode for ground-based seeding. Deposition and condensation freezing were also important for ground-based seeding. Contact freezing was the weakest nucleation mode for both ground-based and airborne seeding. 2) Diffusion and riming on AgI-nucleated ice crystals depleted vapor and liquid water, resulting in more ice-phase precipitation on the ground for all of the seeding cases relative to the control cases. Most of the enhancement came from vapor depletion. The relative enhancement by seeding ranged from 0.3% to 429% under various conditions. 3) The maximum local AgI activation ratio was 60% under optimum conditions. Under most seeding conditions, however, this ratio was between 0.02% and 2% in orographic clouds. 4) The seeding effect was inversely related to the natural precipitation efficiency but was positively related to seeding rates. 5) Ground-based seeding enhanced precipitation on the lee side of the mountain, whereas airborne seeding from lower flight tracks enhanced precipitation on the windward side of the mountain.

The separation of convective and stratiform precipitation regions of simulated Typhoon Chanchu and its sensitivity to the number concentration of cloud droplets

Following a numerical simulation study, we analyze the effect of the parameter of the cloud condensation nuclei concentration (CNP) on Typhoon Chanchu in convective, stratiform, and mixed precipitation areas based on the following three experiments: (1) a control (CTL) experiment using a mesoscale model and the Reisner-2 cloud scheme with the CNP value specified as 100cm−3; (2) a very clean marine (VCM) CNP experiment (CNP=25cm−3); (3) and a severe contamination (SC) CNP experiment (CNP=1000cm−3). We compare and analyze the simulated cloud structure and microphysical processes of the three experiments within the convective, stratiform, and mixed areas. The three precipitating areas are classified based on the ratio of cloud ice content to cloud water content at all precipitating grids proposed by Sui et al. (2007). The results show that the intensities of most microphysical processes are the largest in the convective area and the smallest in the stratiform area. Ice is dominant in the stratiform region and the water hydrometeor is dominant in the convective region. Furthermore, cloud water develops more quickly than cloud ice do in the mixed area. The response of the convective area to a varying CNP is greater than that of the stratiform area, and the mixed area is only slightly sensitive to the CNP. The dominance of cloud microphysical processes related to the growth of water hydrometeors weakens as the CNP increases.

Aircraft measurements of wave clouds

Abstract. In this paper, aircraft measurements are presented of liquid phase (ice-free) wave clouds made at temperatures greater than −5°C that formed over Scotland, UK. The horizontal variations of the vertical velocity across wave clouds display a distinct pattern. The maximum updraughts occur at the upshear flanks of the clouds and the strong downdraughts at the downshear flanks. The cloud droplet concentrations were a couple of hundreds per cubic centimetres, and the drops generally had a mean diameter between 15–45 μm. A small proportion of the drops were drizzle. The measurements presented here and in previous recent studies suggest a different interaction of dynamics and microphysics in wave clouds from the accepted model. The results in this paper provide a case for future numerical simulation of wave cloud and the interaction between wave and cloud.

The effects of mineral dust particles, aerosol regeneration and ice nucleation parameterizations on clouds and precipitation

Abstract. This study focuses on the effects of aerosol particles on the formation of convective clouds and precipitation in the Eastern Mediterranean Sea, with a special emphasis on the role of mineral dust particles in these processes. We used a new detailed numerical cloud microphysics scheme that has been implemented in the Weather Research and Forecast (WRF) model in order to study aerosol–cloud interaction in 3-D configuration based on 1° × 1° resolution reanalysis meteorological data. Using a number of sensitivity studies, we tested the contribution of mineral dust particles and different ice nucleation parameterizations to precipitation development. In this study we also investigated the importance of recycled (regenerated) aerosols that had been released to the atmosphere following the evaporation of cloud droplets. The results showed that increased aerosol concentration due to the presence of mineral dust enhanced the formation of ice crystals. The dynamic evolution of the cloud system sets the time periods and regions in which heavy or light precipitation occurred in the domain. The precipitation rate, the time and duration of precipitation were affected by the aerosol properties only at small spatial scales (with areas of about 20 km2). Changes of the ice nucleation scheme from ice supersaturation-dependent parameterization to a recent approach of aerosol concentration and temperature-dependent parameterization modified the ice crystals concentrations but did not affect the total precipitation in the domain. Aerosol regeneration modified the concentration of cloud droplets at cloud base by dynamic recirculation of the aerosols but also had only a minor effect on precipitation. The major conclusion from this study is that the effect of mineral dust particles on clouds and total precipitation is limited by the properties of the atmospheric dynamics and the only effect of aerosol on precipitation may come from significant increase in the concentration of accumulation mode aerosols. In addition, the presence of mineral dust had a much smaller effect on the total precipitation than on its spatial distribution.