Spatial and temporal distribution of atmospheric aerosols in the lowermost troposphere over the Amazonian tropical rainforest

Abstract. We present measurements of aerosol physico-chemical properties below 5 km altitude over the tropical rain forest and the marine boundary layer (MBL) obtained during the LBA-CLAIRE 1998 project. The MBL aerosol size distribution some 50-100km of the coast of French Guyana and Suriname showed a bi-modal shape typical of aged and cloud processed aerosol. The average particle number density in the MBL was 383cm-3. The daytime mixed layer height over the rain forest for undisturbed conditions was estimated to be between 1200-1500m. During the morning hours the height of the mixed layer increased by 144-180mh-1. The median daytime aerosol number density in the mixed layer increased from 450cm-3 in the morning to almost 800cm-3 in the late afternoon. The evolution of the aerosol size distribution in the daytime mixed layer over the rain forest showed two distinct patterns. Between dawn and midday, the Aitken mode particle concentrations increased, whereas later during the day, a sharp increase of the accumulation mode aerosol number densities was observed, resulting in a doubling of the morning accumulation mode concentrations from 150cm-3 to 300cm-3. Potential sources of the Aitken mode particles are discussed here including the rapid growth of ultrafine aerosol particles formed aloft and subsequently entrained into the mixed layer, as well as the contribution of emissions from the tropical vegetation to Aitken mode number densities. The observed increase of the accumulation mode aerosol number densities is attributed to the combined effect of: the direct emissions of primary biogenic particles from the rain forest and aerosol in-cloud processing by shallow convective clouds. Based on the similarities among the number densities, the size distributions and the composition of the aerosol in the MBL and the nocturnal residual layer we propose that the air originating in the MBL is transported above the nocturnal mixed layer up to 300-400km inland over the rain forest by night without significant processing.

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Spatial and temporal distribution of atmospheric aerosols in the lowermost troposphere over the Amazonian tropical rainforest

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-4-3565-2004 ◽

2004 ◽

Vol 4 (3) ◽

pp. 3565-3606

Author(s):

R. Krejci ◽

J. Ström ◽

M. de Reus ◽

J. Williams ◽

H. Fischer ◽

...

Keyword(s):

Size Distribution ◽

Mixed Layer ◽

Rain Forest ◽

Marine Boundary Layer ◽

Aerosol Size Distribution ◽

Average Particle ◽

Number Density ◽

Modal Shape ◽

Accumulation Mode ◽

Aitken Mode

Abstract. We present measurements of aerosol physico-chemical properties below 5 km altitude over the tropical rain forest and the marine boundary layer (MBL) obtained during the LBA-CLAIRE 1998 project. The MBL aerosol size distribution some 50–100 km of the coast of French Guyana and Suriname showed a bi-modal shape typical of aged and cloud processed aerosol. The average particle number density in the MBL was 383 cm−3. The daytime mixed layer height over the rain forest for undisturbed conditions was estimated to be between 1200–1500 m. During the morning hours the height of the mixed layer increased by 4–5 cm s−1. The median daytime aerosol number density in the mixed layer increased from 450 cm−3 in the morning to almost 800 cm−3 in the late afternoon. The evolution of the aerosol size distribution in the daytime mixed layer over the rain forest showed two distinct patterns. Between dawn and midday, the Aitken mode particle concentrations increased, whereas later during the day, a sharp increase of the accumulation mode aerosol number densities was observed, resulting in a doubling of the morning accumulation mode concentrations from 150 cm−3 to 300 cm−3. Potential sources of the Aitken mode particles are discussed here including the rapid growth of ultrafine aerosol particles formed aloft and subsequently entrained into the mixed layer, as well as the contribution of emissions from the tropical vegetation to Aitken mode number densities. The observed increase of the accumulation mode aerosol number densities is attributed to the combined effect of: the direct emissions of primary biogenic particles from the rain forest and aerosol in-cloud processing by shallow convective clouds. Based on the similarities among the number densities, the size distributions and the composition of the aerosol in the MBL and the nocturnal residual layer we propose that the air originating in the MBL is transported above the nocturnal mixed layer up to 300–400 km inland over the rain forest by night without significant processing.

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One year boundary layer aerosol size distribution data from five Nordic background stations

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-3-2783-2003 ◽

2003 ◽

Vol 3 (3) ◽

pp. 2783-2833 ◽

Cited By ~ 4

Author(s):

P. Tunved ◽

H.-C. Hansson ◽

M. Kulmala ◽

P. Aalto ◽

Y. Viisanen ◽

...

Keyword(s):

Size Distribution ◽

Geographical Area ◽

Aerosol Size Distribution ◽

Distribution Data ◽

Large Variability ◽

Accumulation Mode ◽

One Year ◽

The Impact ◽

Aitken Mode ◽

Aerosol Properties

Abstract. Size distribution measurements performed at five different stations have been investigated during a one-year period between 01 June 2000 and 31 May 2001 with focus on diurnal, seasonal and geographical differences of size distribution properties. The stations involved cover a large geographical area ranging from the Finnish Lapland (67° N) down to southern Sweden (56° N) in the order Värriö, Pallas, Hyytiälä, Aspvreten and Vavihill. The shape of the size distribution is typically bimodal during winter with a larger fraction of accumulation mode particles compared to the other seasons. Highest Aitken mode concentration is found during summer and spring. The maximum of nucleation events occur during spring months. Nucleation events occur during other seasons as well, although not as frequently. Large differences were found between different categories of stations. Northerly located stations such as Pallas and Värriö presented well-separated Aitken and accumulation modes, while the two modes often overlap significantly at the two southernmost stations Vavihill and Aspvreten. A method to cluster trajectories was used to analyse the impact of long-range transport on the observed aerosol properties. Clusters of trajectories arriving from the continent were clearly associated with size distributions shifted towards the accumulation mode. This feature was more pronounced the further south the station was located. Marine- or Arctic-type clusters were associated with large variability in the nuclei size ranges. A quasi-lagrangian approach was used to investigate transport related changes in the aerosol properties. Typically, an increase in especially Aitken mode concentrations was observed when advection from the north occurs, i.e. allowing more continental influence on the aerosol when comparing the different measurement sites. When trajectory clusters arrive to the stations from SW, a gradual decrease in number concentration is experienced in all modes as latitude of measurement site increases.

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One year boundary layer aerosol size distribution data from five nordic background stations

Atmospheric Chemistry and Physics ◽

10.5194/acp-3-2183-2003 ◽

2003 ◽

Vol 3 (6) ◽

pp. 2183-2205 ◽

Cited By ~ 96

Author(s):

P. Tunved ◽

H.-C. Hansson ◽

M. Kulmala ◽

P. Aalto ◽

Y. Viisanen ◽

...

Keyword(s):

Size Distribution ◽

Geographical Area ◽

Aerosol Size Distribution ◽

Distribution Data ◽

Large Variability ◽

Accumulation Mode ◽

One Year ◽

The Impact ◽

Aitken Mode ◽

Aerosol Properties

Abstract. Size distribution measurements performed at five different stations have been investigated during a one-year period between 01 June 2000 and 31 May 2001 with focus on diurnal, seasonal and geographical differences of size distribution properties. The stations involved cover a large geographical area ranging from the Finnish Lapland (67º N) down to southern Sweden (56º N) in the order Värriö, Pallas, Hyytiälä, Aspvreten and Vavihill. The shape of the size distribution is typically bimodal during winter with a larger fraction of accumulation mode particles compared to the other seasons. Highest Aitken mode concentration is found during summer and spring during the year of study. The maximum of nucleation events occur during the spring months at all stations. Nucleation events occur during other months as well, although not as frequently. Large differences were found between different categories of stations. Northerly located stations such as Pallas and Värriö presented well-separated Aitken and accumulation modes, while the two modes often overlap significantly at the two southernmost stations Vavihill and Aspvreten. A method to cluster trajectories was used to analyse the impact of long-range transport on the observed aerosol properties. Clusters of trajectories arriving from the continent were clearly associated with size distributions shifted towards the accumulation mode. This feature was more pronounced the further south the station was located. Marine- or Arctic-type clusters were associated with large variability in the nuclei size ranges. A quasi-lagrangian approach was used to investigate transport related changes in the aerosol properties. Typically, an increase in especially Aitken mode concentrations was observed when advection from the north occurs, i.e. allowing more continental influence on the aerosol when comparing the different measurement sites. When trajectory clusters arrive to the stations from SW, a gradual decrease in number concentration is experienced in all modes as latitude of measurement site increases.

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Evaluation of a global aerosol microphysics model against size-resolved particle statistics in the marine atmosphere

Atmospheric Chemistry and Physics ◽

10.5194/acp-7-2073-2007 ◽

2007 ◽

Vol 7 (8) ◽

pp. 2073-2090 ◽

Cited By ~ 43

Author(s):

D. V. Spracklen ◽

K. J. Pringle ◽

K. S. Carslaw ◽

G. W. Mann ◽

P. Manktelow ◽

...

Keyword(s):

Marine Boundary Layer ◽

Geometric Mean ◽

Carbonaceous Material ◽

Mode Number ◽

Anthropogenic Sources ◽

Substantial Contribution ◽

Particle Size Range ◽

Accumulation Mode ◽

Tropospheric Aerosol ◽

Aitken Mode

Abstract. A statistical synthesis of marine aerosol measurements from experiments in four different oceans is used to evaluate a global aerosol microphysics model (GLOMAP). We compare the model against observed size resolved particle concentrations, probability distributions, and the temporal persistence of different size particles. We attempt to explain the observed sub-micrometre size distributions in terms of sulfate and sea spray and quantify the possible contributions of anthropogenic sulfate and carbonaceous material to the number and mass distribution. The model predicts a bimodal size distribution that agrees well with observations as a grand average over all regions, but there are large regional differences. Notably, observed Aitken mode number concentrations are more than a factor 10 higher than in the model for the N Atlantic but a factor 7 lower than the model in the NW Pacific. We also find that modelled Aitken mode and accumulation mode geometric mean diameters are generally smaller in the model by 10–30%. Comparison with observed free tropospheric Aitken mode distributions suggests that the model underpredicts growth of these particles during descent to the marine boundary layer (MBL). Recent observations of a substantial organic component of free tropospheric aerosol could explain this discrepancy. We find that anthropogenic continental material makes a substantial contribution to N Atlantic MBL aerosol, with typically 60–90% of sulfate across the particle size range coming from anthropogenic sources, even if we analyse air that has spent an average of >120 h away from land. However, anthropogenic primary black carbon and organic carbon particles (at the emission size and quantity assumed here) do not explain the large discrepancies in Aitken mode number. Several explanations for the discrepancy are suggested. The lack of lower atmospheric particle formation in the model may explain low N Atlantic particle concentrations. However, the observed and modelled particle persistence at Cape Grim in the Southern Ocean, does not reveal a diurnal cycle consistent with a photochemically driven local particle source. We also show that a physically based cloud drop activation scheme better explains the observed change in accumulation mode geometric mean diameter with particle number.

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A global off-line model of size-resolved aerosol microphysics: I. Model development and prediction of aerosol properties

Atmospheric Chemistry and Physics ◽

10.5194/acp-5-2227-2005 ◽

2005 ◽

Vol 5 (8) ◽

pp. 2227-2252 ◽

Cited By ~ 213

Author(s):

D. V. Spracklen ◽

K. J. Pringle ◽

K. S. Carslaw ◽

M. P. Chipperfield ◽

G. W. Mann

Keyword(s):

Boundary Layer ◽

Sulfuric Acid ◽

Size Distribution ◽

Marine Boundary Layer ◽

Transport Model ◽

Model Development ◽

Aerosol Size Distribution ◽

Chemical Transport Model ◽

Cloud Processing ◽

Nucleation Mechanisms

Abstract. A GLObal Model of Aerosol Processes (GLOMAP) has been developed as an extension to the TOMCAT 3-D Eulerian off-line chemical transport model. GLOMAP simulates the evolution of the global aerosol size distribution using a sectional two-moment scheme and includes the processes of aerosol nucleation, condensation, growth, coagulation, wet and dry deposition and cloud processing. We describe the results of a global simulation of sulfuric acid and sea spray aerosol. The model captures features of the aerosol size distribution that are well established from observations in the marine boundary layer and free troposphere. Modelled condensation nuclei (CN>3nm) vary between about 250–500 cm-3 in remote marine boundary layer regions and are generally in good agreement with observations. Modelled continental CN concentrations are lower than observed, which may be due to lack of some primary aerosol sources or the neglect of nucleation mechanisms other than binary homogeneous nucleation of sulfuric acid-water particles. Remote marine CN concentrations increase to around 2000–10 000 cm

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Multi-year statistical and modelling analysis of submicrometer aerosol number size distributions at a rain forest site in Amazonia

10.5194/acp-2018-55 ◽

2018 ◽

Author(s):

Luciana Varanda Rizzo ◽

Pontus Roldin ◽

Joel Brito ◽

John Backman ◽

Erik Swietlicki ◽

...

Keyword(s):

Particle Size ◽

Rain Forest ◽

Amazon Basin ◽

Particle Number ◽

Dry Season ◽

Forest Site ◽

Size Distributions ◽

Wet Season ◽

Accumulation Mode ◽

Aitken Mode

Abstract. The Amazon Basin is a unique region to study atmospheric aerosols, given their relevance for the regional hydrological cycle and large uncertainty of their sources. Multi-year datasets are crucial when contrasting periods of natural conditions and periods influenced by anthropogenic emissions. In the wet season, biogenic sources and processes prevail, and the Amazonian atmospheric composition resembles pre-industrial conditions. In the dry season, the Basin is influenced by widespread biomass burning emissions. This work reports multi-year observations of high time resolution submicrometer (10–600 nm) particle number size distributions at a rain forest site in Amazonia (TT34 tower, 60 km NW from Manaus city), between years 2008–2010 and 2012–2014. Median particle number concentration was 403 cm−3 in the wet season and 1254 cm−3 in the dry season. The Aitken mode (~ 30–100 nm in diameter) was prominent during the wet season, while accumulation mode (~ 100–600 nm in diameter) dominated the particle size spectra during the dry season. Cluster analysis identified groups of aerosol number size distribution influenced by convective downdrafts, nucleation events and fresh biomass burning emissions. New particle formation and subsequent growth was rarely observed during the 749 days of observations, similar to previous observations in the Amazon Basin. A stationary 1D column model (ADCHEM – Aerosol Dynamics, gas and particle phase CHEMistry and radiative transfer model) was used to assess importance of processes behind the observed diurnal particle size distribution trends. Three major particle source types are required in the model to reproduce the observations: (i) a surface source of particles in the evening, possibly related to primary biological emissions (ii) entrainment of accumulation mode aerosols in the morning, and (iii) convective downdrafts transporting Aitken mode particles into the boundary layer mostly during the afternoon. The latter process has the largest influence on the modelled particle number size distributions. However, convective downdrafts are often associated with rain and thus act both as a source of Aitken mode particles, and as a sink of accumulation mode particles, causing a net reduction in the median total particle number concentrations in the surface layer. Our study shows that the combination of the three mentioned particle sources are essential to sustain particle number concentrations in Amazonia.

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Marine boundary layer aerosol in the eastern North Atlantic: seasonal variations and key controlling processes

Atmospheric Chemistry and Physics ◽

10.5194/acp-18-17615-2018 ◽

2018 ◽

Vol 18 (23) ◽

pp. 17615-17635 ◽

Cited By ~ 10

Author(s):

Guangjie Zheng ◽

Yang Wang ◽

Allison C. Aiken ◽

Francesca Gallo ◽

Michael P. Jensen ◽

...

Keyword(s):

Boundary Layer ◽

North Atlantic ◽

Seasonal Variations ◽

Dimethyl Sulfide ◽

Marine Boundary Layer ◽

Sulfide Oxidation ◽

Aerosol Size Distribution ◽

Eastern North Atlantic ◽

Aitken Mode ◽

Aerosol Properties

Abstract. The response of marine low cloud systems to changes in aerosol concentration represents one of the largest uncertainties in climate simulations. Major contributions to this uncertainty are derived from poor understanding of aerosol under natural conditions and the perturbation by anthropogenic emissions. The eastern North Atlantic (ENA) is a region of persistent but diverse marine boundary layer (MBL) clouds, whose albedo and precipitation are highly susceptible to perturbations in aerosol properties. In this study, we examine MBL aerosol properties, trace gas mixing ratios, and meteorological parameters measured at the Atmospheric Radiation Measurement Climate Research Facility's ENA site on Graciosa Island, Azores, Portugal, during a 3-year period from 2015 to 2017. Measurements impacted by local pollution on Graciosa Island and during occasional intense biomass burning and dust events are excluded from this study. Submicron aerosol size distribution typically consists of three modes: Aitken (At, diameter Dp<∼100 nm), accumulation (Ac, Dp within ∼100 to ∼300 nm), and larger accumulation (LA, Dp>∼300 nm) modes, with average number concentrations (denoted as NAt, NAc, and NLA below) of 330, 114, and 14 cm−3, respectively. NAt, NAc, and NLA show contrasting seasonal variations, suggesting different sources and removal processes. NLA is dominated by sea spray aerosol (SSA) and is higher in winter and lower in summer. This is due to the seasonal variations of SSA production, in-cloud coalescence scavenging, and dilution by entrained free troposphere (FT) air. In comparison, SSA typically contributes a relatively minor fraction to NAt (10 %) and NAc (21 %) on an annual basis. In addition to SSA, sources of Ac-mode particles include entrainment of FT aerosols and condensation growth of Aitken-mode particles inside the MBL, while in-cloud coalescence scavenging is the major sink of NAc. The observed seasonal variation of NAc, being higher in summer and lower in winter, generally agrees with the steady-state concentration estimated from major sources and sinks. NAt is mainly controlled by entrainment of FT aerosol, coagulation loss, and growth of Aitken-mode particles into the Ac-mode size range. Our calculation suggests that besides the direct contribution from entrained FT Ac-mode particles, growth of entrained FT Aitken-mode particles in the MBL also represent a substantial source of cloud condensation nuclei (CCN), with the highest contribution potentially reaching 60 % during summer. The growth of Aitken-mode particles to CCN size is an expected result of the condensation of sulfuric acid, a product from dimethyl sulfide oxidation, suggesting that ocean ecosystems may have a substantial influence on MBL CCN populations in the ENA.

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The time evolution of aerosol size distribution over the Mexico City plateau

Atmospheric Chemistry and Physics ◽

10.5194/acp-9-4261-2009 ◽

2009 ◽

Vol 9 (13) ◽

pp. 4261-4278 ◽

Cited By ~ 44

Author(s):

L. I. Kleinman ◽

S. R. Springston ◽

J. Wang ◽

P. H. Daum ◽

Y.-N. Lee ◽

...

Keyword(s):

Size Distribution ◽

Mexico City ◽

Volume Growth ◽

Fold Increase ◽

Number Concentration ◽

Aerosol Size Distribution ◽

Detailed Model ◽

Accumulation Mode ◽

Mode Size ◽

Aerosol Volume

Abstract. As part of the MILAGRO field campaign, the DOE G-1 aircraft was used to make measurements over and downwind of Mexico City with the objective of determining growth characteristics of aerosols from a megacity urban source. This study focuses on number concentration and size distributions. It is found that a 5-fold increase in aerosol volume is accompanied by about a 5-fold increase in accumulation mode number concentration. There is growth in aerosol volume because there are more accumulation mode particles, not because of an increase in the average size of accumulation particles. Condensation and volume growth laws were examined to see whether either is consistent with observations. Condensation calculations show that the growth of Aitken mode particles into the accumulation mode size range gives the required increase in number concentration. There are minimal changes in the accumulation mode size distribution with age, consistent with observations. Volume-growth in contrast yields a population of large particles, distinctly different from what is observed. Detailed model calculations are required to translate our observations into specific information on the volatility and properties of secondary organic aerosol.

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Multi-year statistical and modeling analysis of submicrometer aerosol number size distributions at a rain forest site in Amazonia

Atmospheric Chemistry and Physics ◽

10.5194/acp-18-10255-2018 ◽

2018 ◽

Vol 18 (14) ◽

pp. 10255-10274 ◽

Cited By ~ 8

Author(s):

Luciana Varanda Rizzo ◽

Pontus Roldin ◽

Joel Brito ◽

John Backman ◽

Erik Swietlicki ◽

...

Keyword(s):

Particle Size ◽

Rain Forest ◽

Amazon Basin ◽

Particle Number ◽

Dry Season ◽

Forest Site ◽

Size Distributions ◽

Wet Season ◽

Accumulation Mode ◽

Aitken Mode

Abstract. The Amazon Basin is a unique region to study atmospheric aerosols, given their relevance for the regional hydrological cycle and the large uncertainty of their sources. Multi-year datasets are crucial when contrasting periods of natural conditions and periods influenced by anthropogenic emissions. In the wet season, biogenic sources and processes prevail, and the Amazonian atmospheric composition resembles preindustrial conditions. In the dry season, the basin is influenced by widespread biomass burning emissions. This work reports multi-year observations of high time resolution submicrometer (10–600 nm) particle number size distributions at a rain forest site in Amazonia (TT34 tower, 60 km NW from Manaus city), between 2008 and 2010 and 2012 and 2014. The median particle number concentration was 403 cm−3 in the wet season and 1254 cm−3 in the dry season. The Aitken mode (∼ 30–100 nm in diameter) was prominent during the wet season, while the accumulation mode (∼ 100–600 nm in diameter) dominated the particle size spectra during the dry season. Cluster analysis identified groups of aerosol number size distributions influenced by convective downdrafts, nucleation events and fresh biomass burning emissions. New particle formation and subsequent growth was rarely observed during the 749 days of observations, similar to previous observations in the Amazon Basin. A stationary 1-D column model (ADCHEM – Aerosol Dynamics, gas and particle phase CHEMistry and radiative transfer model) was used to assess the importance of the processes behind the observed diurnal particle size distribution trends. Three major particle source types are required in the model to reproduce the observations: (i) a surface source of particles in the evening, possibly related to primary biological emissions; (ii) entrainment of accumulation mode aerosols in the morning; and (iii) convective downdrafts transporting Aitken mode particles into the boundary layer mostly during the afternoon. The latter process has the largest influence on the modeled particle number size distributions. However, convective downdrafts are often associated with rain and, thus, act as both a source of Aitken mode particles and a sink of accumulation mode particles, causing a net reduction in the median total particle number concentrations in the surface layer. Our study shows that the combination of the three mentioned particle sources is essential to sustain particle number concentrations in Amazonia.

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Long-term observations of cloud condensation nuclei in the Amazon rain forest – Part 1: Aerosol size distribution, hygroscopicity, and new model parametrizations for CCN prediction

Atmospheric Chemistry and Physics ◽

10.5194/acp-16-15709-2016 ◽

2016 ◽

Vol 16 (24) ◽

pp. 15709-15740 ◽

Cited By ~ 45

Author(s):

Mira L. Pöhlker ◽

Christopher Pöhlker ◽

Florian Ditas ◽

Thomas Klimach ◽

Isabella Hrabe de Angelis ◽

...

Keyword(s):

Size Distribution ◽

Aerosol Particle ◽

Rain Forest ◽

Seasonal Cycle ◽

Cloud Condensation Nuclei ◽

Number Concentration ◽

Aerosol Size Distribution ◽

Condensation Nuclei ◽

Central Amazon

Abstract. Size-resolved long-term measurements of atmospheric aerosol and cloud condensation nuclei (CCN) concentrations and hygroscopicity were conducted at the remote Amazon Tall Tower Observatory (ATTO) in the central Amazon Basin over a 1-year period and full seasonal cycle (March 2014–February 2015). The measurements provide a climatology of CCN properties characteristic of a remote central Amazonian rain forest site.The CCN measurements were continuously cycled through 10 levels of supersaturation (S  =  0.11 to 1.10 %) and span the aerosol particle size range from 20 to 245 nm. The mean critical diameters of CCN activation range from 43 nm at S  =  1.10 % to 172 nm at S  =  0.11 %. The particle hygroscopicity exhibits a pronounced size dependence with lower values for the Aitken mode (κAit  =  0.14 ± 0.03), higher values for the accumulation mode (κAcc  =  0.22 ± 0.05), and an overall mean value of κmean  =  0.17 ± 0.06, consistent with high fractions of organic aerosol.The hygroscopicity parameter, κ, exhibits remarkably little temporal variability: no pronounced diurnal cycles, only weak seasonal trends, and few short-term variations during long-range transport events. In contrast, the CCN number concentrations exhibit a pronounced seasonal cycle, tracking the pollution-related seasonality in total aerosol concentration. We find that the variability in the CCN concentrations in the central Amazon is mostly driven by aerosol particle number concentration and size distribution, while variations in aerosol hygroscopicity and chemical composition matter only during a few episodes.For modeling purposes, we compare different approaches of predicting CCN number concentration and present a novel parametrization, which allows accurate CCN predictions based on a small set of input data.

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