Simulating ultrafine particle formation in Europe using a regional CTM: contribution of primary emissions versus secondary formation to aerosol number concentrations

Abstract. A three-dimensional regional chemical transport model (CTM) with detailed aerosol microphysics, PMCAMx-UF, was applied to the European domain to simulate the contribution of direct emissions and secondary formation to total particle number concentrations during May 2008. PMCAMx-UF uses the Dynamic Model for Aerosol Nucleation and the Two-Moment Aerosol Sectional (TOMAS) algorithm to track both aerosol number and mass concentration using a sectional approach. The model predicts nucleation events that occur over scales of hundreds up to thousands of kilometers especially over the Balkans and Southeast Europe. The model predictions were compared against measurements from 7 sites across Europe. The model reproduces more than 70% of the hourly concentrations of particles larger than 10 nm (N10) within a factor of 2. About half of these particles are predicted to originate from nucleation in the lower troposphere. Regional nucleation is predicted to increase the total particle number concentration by approximately a factor of 3. For particles larger than 100 nm the effect varies from an increase of 20% in the eastern Mediterranean to a decrease of 20% in southern Spain and Portugal resulting in a small average increase of around 1% over the whole domain. Nucleation has a significant effect in the predicted N50 levels (up to a factor of 2 increase) mainly in areas where there are condensable vapors to grow the particles to larger sizes. A semi-empirical ternary sulfuric acid-ammonia-water parameterization performs better than the activation or the kinetic parameterizations in reproducing the observations. Reducing emissions of ammonia and sulfur dioxide affects certain parts of the number size distribution.

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Simulating ultrafine particle formation in Europe using a regional CTM: contribution of primary emissions versus secondary formation to aerosol number concentrations

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-12-13581-2012 ◽

2012 ◽

Vol 12 (6) ◽

pp. 13581-13617 ◽

Cited By ~ 1

Author(s):

C. Fountoukis ◽

I. Riipinen ◽

H. A. C. Denier van der Gon ◽

P. E. Charalampidis ◽

C. Pilinis ◽

...

Keyword(s):

Particle Number ◽

Transport Model ◽

Eastern Mediterranean ◽

Lower Troposphere ◽

Southeast Europe ◽

Chemical Transport Model ◽

The Balkans ◽

Total Particle Number ◽

Secondary Formation ◽

Total Particle

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Implementing growth and sedimentation of NAT particles in a global Eulerian model

Atmospheric Chemistry and Physics ◽

10.5194/acp-4-1869-2004 ◽

2004 ◽

Vol 4 (7) ◽

pp. 1869-1883 ◽

Cited By ~ 13

Author(s):

M. M. P. van den Broek ◽

J. E. Williams ◽

A. Bregman

Keyword(s):

Particle Number ◽

Transport Model ◽

Particle Diameter ◽

Particle Growth ◽

Particle Number Density ◽

Lagrangian Model ◽

Number Density ◽

Model Study ◽

Total Particle Number ◽

Total Particle

Abstract. Here we present a concise and efficient algorithm to mimic the growth and sedimentation of Nitric Acid Trihydate (NAT) particles in the polar vortex in a state-of-the-art 3D chemistry transport model. The particle growth and sedimentation are calculated using the microphysical formulation of Carslaw et al. (2002). Once formed, NAT particles are transported in the model as tracers in the form of size-segregated quantities or size bins. Two different approaches were adopted for this purpose: one assuming a fixed particle number density ("FixedDens") and the other assuming a discrete set of particle diameter values ("FixedRad"). Simulations were performed for three separate 10-day periods during the 1999-2000 Arctic winter and compared to the results of an existing Lagrangian model study, which uses similar microphysics in a computationally more expensive method for the simulation of NAT particle growth. The resulting particle sizes for both our approaches compare favourably at 430K with those obtained from this previous model study, and also in-situ observations related to the size of large NAT particles. The particle growth is faster for "FixedDens" resulting in a difference in (de)nitrification by a factor of ~2 for all three simulation periods. Comparisons were made with a standard equilibrium approach and the differences in the redistribution of HNO3 were found to be substantial. For both approaches the performance of the algorithm is rather insensitive to both the number of size bins and the shape of the size distribution, and show a weak dependence on the prescribed total particle number density during the coldest period. This results in an increase of 7% for the "FixedRad" approach and 17% for the "FixedDens" approach when increasing the total particle number density by a factor of 2.5.

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Impact of the Coronavirus Pandemic Lockdown on Atmospheric Nanoparticle Concentrations in Two Sites of Southern Italy

Atmosphere ◽

10.3390/atmos12030352 ◽

2021 ◽

Vol 12 (3) ◽

pp. 352

Author(s):

Adelaide Dinoi ◽

Daniel Gulli ◽

Ivano Ammoscato ◽

Claudia R. Calidonna ◽

Daniele Contini

Keyword(s):

Particle Number ◽

Southern Italy ◽

Time Intervals ◽

Atmospheric Particle ◽

Total Particle Number ◽

Total Particle ◽

Consequent Reduction ◽

Containment Measures ◽

Coronavirus Infection ◽

The Impact

During the new coronavirus infection outbreak, the application of strict containment measures entailed a decrease in most human activities, with the consequent reduction of anthropogenic emissions into the atmosphere. In this study, the impact of lockdown on atmospheric particle number concentrations and size distributions is investigated in two different sites of Southern Italy: Lecce and Lamezia Terme, regional stations of the GAW/ACTRIS networks. The effects of restrictions are quantified by comparing submicron particle concentrations, in the size range from 10 nm to 800 nm, measured during the lockdown period and in the same period of previous years, from 2015 to 2019, considering three time intervals: prelockdown, lockdown and postlockdown. Different percentage reductions in total particle number concentrations are observed, −19% and −23% in Lecce and −7% and −4% in Lamezia Terme during lockdown and postlockdown, respectively, with several variations in each subclass of particles. From the comparison, no significant variations of meteorological factors are observed except a reduction of rainfall in 2020, which might explain the higher levels of particle concentrations measured during prelockdown at both stations. In general, the results demonstrate an improvement of air quality, more conspicuous in Lecce than in Lamezia Terme, during the lockdown, with a differed reduction in the concentration of submicronic particles that depends on the different types of sources, their distance from observational sites and local meteorology.

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Ice nucleating particles over the Eastern Mediterranean measured by unmanned aircraft systems

Atmospheric Chemistry and Physics ◽

10.5194/acp-17-4817-2017 ◽

2017 ◽

Vol 17 (7) ◽

pp. 4817-4835 ◽

Cited By ~ 27

Author(s):

Jann Schrod ◽

Daniel Weber ◽

Jaqueline Drücke ◽

Christos Keleshis ◽

Michael Pikridas ◽

...

Keyword(s):

Transport Model ◽

Eastern Mediterranean ◽

Lower Troposphere ◽

Ground Level ◽

Ice Nucleation ◽

Unmanned Aircraft ◽

Unmanned Aircraft Systems ◽

Saharan Dust ◽

Cloud Formation ◽

Aircraft Systems

Abstract. During an intensive field campaign on aerosol, clouds, and ice nucleation in the Eastern Mediterranean in April 2016, we measured the abundance of ice nucleating particles (INPs) in the lower troposphere from unmanned aircraft systems (UASs). Aerosol samples were collected by miniaturized electrostatic precipitators onboard the UASs at altitudes up to 2.5 km. The number of INPs in these samples, which are active in the deposition and condensation modes at temperatures from −20 to −30 °C, were analyzed immediately after collection on site using the ice nucleus counter FRIDGE (FRankfurt Ice nucleation Deposition freezinG Experiment). During the 1-month campaign, we encountered a series of Saharan dust plumes that traveled at several kilometers' altitude. Here we present INP data from 42 individual flights, together with aerosol number concentrations, observations of lidar backscattering, dust concentrations derived by the dust transport model DREAM (Dust Regional Atmospheric Model), and results from scanning electron microscopy. The effect of the dust plumes is reflected by the coincidence of INPs with the particulate matter (PM), the lidar signal, and the predicted dust mass of the model. This suggests that mineral dust or a constituent related to dust was a major contributor to the ice nucleating properties of the aerosol. Peak concentrations of above 100 INPs std L−1 were measured at −30 °C. The INP concentration in elevated plumes was on average a factor of 10 higher than at ground level. Since desert dust is transported for long distances over wide areas of the globe predominantly at several kilometers' altitude, we conclude that INP measurements at ground level may be of limited significance for the situation at the level of cloud formation.

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Vertical marine snow distribution in the stratified, hypersaline, and anoxic Orca Basin (Gulf of Mexico)

Elem Sci Anth ◽

10.1525/elementa.348 ◽

2019 ◽

Vol 7 ◽

Cited By ~ 3

Author(s):

Arne Diercks ◽

Kai Ziervogel ◽

Ryan Sibert ◽

Samantha B. Joye ◽

Vernon Asper ◽

...

Keyword(s):

Organic Carbon ◽

Gulf Of Mexico ◽

Particle Number ◽

Sea Surface ◽

Marine Snow ◽

Particle Volume ◽

Total Particle Number ◽

Total Particle ◽

Snow Distribution ◽

Orca Basin

We present a complete description of the depth distribution of marine snow in Orca Basin (Gulf of Mexico), from sea surface through the pycnocline to within 10 m of the seafloor. Orca Basin is an intriguing location for studying marine snow because of its unique geological and hydrographic setting: the deepest ~200 m of the basin are filled with anoxic hypersaline brine. A typical deep ocean profile of marine snow distribution was observed from the sea surface to the pycnocline, namely a surface maximum in total particle number and midwater minimum. However, instead of a nepheloid (particle-rich) layer positioned near the seabed, the nepheloid layer in the Orca Basin was positioned atop the brine. Within the brine, the total particle volume increased by a factor of 2–3 while the total particle number decreased, indicating accumulation and aggregation of material in the brine. From these observations we infer increased residence time and retention of material within the brine, which agrees well with laboratory results showing a 2.2–3.5-fold reduction in settling speed of laboratory-generated marine snow below the seawater-brine interface. Similarly, dissolved organic carbon concentration in the brine correlated positively with measured colored dissolved organic matter (r2 = 0.92, n = 15), with both variables following total particle volume inversely through the pycnocline. These data indicate the release of dissolved organic carbon concomitant with loss in total particle volume and increase in particle numbers at the brine-seawater interface, highlighting the importance of the Orca Basin as a carbon sink.

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A tropospheric chemistry reanalysis for the years 2005–2012 based on an assimilation of OMI, MLS, TES and MOPITT satellite data

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-15-8687-2015 ◽

2015 ◽

Vol 15 (6) ◽

pp. 8687-8770

Author(s):

K. Miyazaki ◽

H. J. Eskes ◽

K. Sudo

Keyword(s):

Transport Model ◽

Lower Troposphere ◽

Tropospheric Chemistry ◽

Atmospheric Environment ◽

Data Sets ◽

Chemical Transport Model ◽

Observational Estimate ◽

Multiple Species ◽

Chemical Fields

Abstract. We present the results from an eight-year tropospheric chemistry reanalysis for the period 2005–2012 obtained by assimilating multiple retrieval data sets from the OMI, MLS, TES, and MOPITT satellite instruments. The reanalysis calculation was conducted using a global chemical transport model and an ensemble Kalman filter technique that simultaneously optimises the chemical concentrations of various species and emissions of several precursors. The optimisation of both the concentration and the emission fields is an efficient method to correct the entire tropospheric profile and its year-to-year variations, and to adjust various tracers chemically linked to the species assimilated. Comparisons against independent aircraft, satellite, and ozonesonde observations demonstrate the quality of the analysed O3, NO2, and CO concentrations on regional and global scales and for both seasonal and year-to-year variations from the lower troposphere to the lower stratosphere. The data assimilation statistics imply persistent reduction of model error and improved representation of emission variability, but also show that discontinuities in the availability of the measurements lead to a degradation of the reanalysis. The decrease in the number of assimilated measurements increased the ozonesonde minus analysis difference after 2010 and caused spurious variations in the estimated emissions. The Northern/Southern Hemisphere OH ratio was modified considerably due to the multiple species assimilation and became closer to an observational estimate, which played an important role in propagating observational information among various chemical fields and affected the emission estimates. The consistent concentration and emission products provide unique information on year-to-year variations of the atmospheric environment.

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Urban aerosol size distributions over the Mediterranean city of Barcelona, NE Spain

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-12-16457-2012 ◽

2012 ◽

Vol 12 (7) ◽

pp. 16457-16492 ◽

Cited By ~ 3

Author(s):

M. Dall'Osto ◽

D.C.S. Beddows ◽

J. Pey ◽

S. Rodriguez ◽

A. Alastuey ◽

...

Keyword(s):

Particle Number ◽

Number Concentration ◽

Aerosol Size Distribution ◽

Time Variability ◽

Small Contribution ◽

Particle Number Concentration ◽

Size Distributions ◽

Total Particle Number ◽

Total Particle ◽

One Year

Abstract. Differential mobility particle sizer (DMPS) aerosol concentrations (N13–800) were collected over a one-year-period (2004) at an urban background site in Barcelona, North-Eastern Spain. Quantitative contributions to particle number concentrations of the nucleation (33–38%), Aitken (39–49%) and accumulation mode (18–22%) were estimated. We examined the source and time variability of atmospheric aerosol particles by using both K-means clustering and Positive Matrix Factorization (PMF) analysis. Performing clustering analysis on hourly size distributions, nine K-means DMPS clusters were identified and, by directional association, diurnal variation and relationship to meteorological and pollution variables, four typical aerosol size distribution scenarios were identified: traffic (69% of the time), dilution (15% of the time), summer background conditions (4% of the time) and regional pollution (12% of the time). According to the results of PMF, vehicle exhausts are estimated to contribute at least to 62–66% of the total particle number concentration, with a slightly higher proportion distributed towards the nucleation mode (34%) relative to the Aitken mode (28–32%). Photochemically induced nucleation particles make only a small contribution to the total particle number concentration (2–3% of the total), although only particles larger than 13 nm were considered in this study. Overall the combination of the two statistical methods is successful at separating components and quantifying relative contributions to the particle number population.

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Long-Term Characterization of Submicron Atmospheric Particles in an Urban Background Site in Southern Italy

Atmosphere ◽

10.3390/atmos11040334 ◽

2020 ◽

Vol 11 (4) ◽

pp. 334 ◽

Cited By ~ 3

Author(s):

Adelaide Dinoi ◽

Marianna Conte ◽

Fabio M. Grasso ◽

Daniele Contini

Keyword(s):

Particle Number ◽

Meteorological Parameters ◽

Particle Diameter ◽

Number Concentration ◽

Total Particle Number ◽

Total Particle ◽

Late Evening ◽

20 Nm

Continuous measurements of particle number size distributions in the size range from 10 nm to 800 nm were performed from 2015 to 2019 at the ECO Environmental-Climate Observatory of Lecce (Global Atmosphere Watch Programme/Aerosol, Clouds and Trace Gases Research Infrastructure (GAW/ACTRIS) regional station). The main objectives of this work were to investigate the daily, weekly and seasonal trends of particle number concentrations and their dependence on meteorological parameters gathering information on potential sources. The highest total number concentrations were observed during autumn-winter with average values nearly twice as high as in summer. More than 52% of total particle number concentration consisted of Aitken mode (20 nm < particle diameter (Dp) < 100 nm) particles followed by accumulation (100 nm < Dp < 800 nm) and nucleation (10 nm < Dp < 20 nm) modes representing, respectively, 27% and 21% of particles. The total number concentration was usually significantly higher during workdays than during weekends/holidays in all years, showing a trend likely correlated with local traffic activities. The number concentration of each particle mode showed a characteristic daily variation that was different in cold and warm seasons. The highest concentrations of the Aitken and accumulation particle mode were observed in the morning and the late evening, during typical rush hour traffic times, highlighting that the two-particle size ranges are related, although there was significant variation in the number concentrations. The peak in the number concentrations of the nucleation mode observed in the midday of spring and summer can be attributed to the intensive formation of new particles from gaseous precursors. Based on Pearson coefficients between particle number concentrations and meteorological parameters, temperature, and wind speed had significant negative relationships with the Aitken and accumulation particle number concentrations, whereas relative humidity was positively correlated. No significant correlations were found for the nucleation particle number concentrations.

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Classification of aerosol population type and cloud condensation nuclei properties in a coastal California littoral environment using an unsupervised cluster model

10.5194/acp-2018-1297 ◽

2019 ◽

Author(s):

Samuel A. Atwood ◽

Sonia M. Kreidenweis ◽

Paul J. DeMott ◽

Markus D. Petters ◽

Gavin C. Cornwell ◽

...

Keyword(s):

Cluster Model ◽

Particle Number ◽

Cloud Condensation Nuclei ◽

Sea Breeze ◽

Northern Coast ◽

Size Distributions ◽

Condensation Nuclei ◽

Entire Study ◽

Total Particle Number ◽

Total Particle

Abstract. Aerosol particle and cloud condensation nuclei (CCN) measurements from a littoral location on the northern coast of California at Bodega Bay Marine Laboratory (BML) are presented for approximately six weeks of observations during the CalWater-2015 field campaign. A combination of aerosol microphysical and meteorological parameters was used to classify variability in the properties of the BML surface aerosol using a K-means cluster model. Eight aerosol population types were identified that were associated with a range of impacts from both marine and terrestrial sources. Average measured total particle number concentrations, size distributions, hygroscopicities, and activated fraction spectra between 0.08 % and 1.1 % supersaturation are given for each of the identified aerosol population types, along with meteorological observations and transport pathways during time periods associated with each type. Five terrestrially influenced aerosol population types represented different degrees of aging of the continental outflow from the coast and interior of California and their appearance at the BML site was often linked to changes in wind direction and transport pathway. In particular, distinct aerosol populations, associated with diurnal variations in source region induced by land/sea-breeze shifts, were classified by the clustering technique. A terrestrial type representing fresh emissions, and/or a recent new particle formation event, occurred in approximately 10 % of the observations. Over the entire study period, three marine influenced population types were identified that typically occurred when the regular diurnal land/sea-breeze cycle collapsed and BML was continuously ventilated by air masses from marine regions for multiple days. These marine types differed from each other primarily in the degree of cloud processing evident in the size distributions, and in the presence of an additional large-particle mode for the type associated with the highest wind speeds. One of the marine types was associated with a multi-day period during which an atmospheric river made landfall at BML. The generally higher total particle number concentrations but lower activated fractions of four of the terrestrial types yielded similar CCN number concentrations to two of the marine types for supersaturations below about 0.4 %. Despite quite different activated fraction spectra, the two remaining marine and terrestrial types had CCN spectral number concentrations very similar to each other, due in part to higher number concentrations associated with the terrestrial type.

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Formaldehyde over the eastern Mediterranean during MINOS: Comparison of airborne in-situ measurements with 3D-model results

Atmospheric Chemistry and Physics ◽

10.5194/acp-3-851-2003 ◽

2003 ◽

Vol 3 (3) ◽

pp. 851-861 ◽

Cited By ~ 40

Author(s):

R. Kormann ◽

H. Fischer ◽

M. de Reus ◽

M. Lawrence ◽

Ch. Brühl ◽

...

Keyword(s):

Boundary Layer ◽

3D Model ◽

Transport Model ◽

Eastern Mediterranean ◽

Lower Atmosphere ◽

Photochemical Degradation ◽

Chemical Transport Model ◽

Acetone Concentration ◽

Volatile Organic ◽

The Mediterranean

Abstract. Formaldehyde (HCHO) is an important intermediate product in the photochemical degradation of methane and non-methane volatile organic compounds. In August 2001, airborne formaldehyde measurements based on the Hantzsch reaction technique were performed during the Mediterranean INtensive Oxidant Study, MINOS. The detection limit of the instrument was 42 pptv (1s) at a time resolution of 180 s (10-90%). The overall uncertainty of the HCHO measurements was 30% at a mixing ratio of 300 pptv. In the marine boundary layer over the eastern Mediterranean Sea average HCHO concentrations were of the order of 1500 pptv, in reasonable agreement with results from a three-dimensional global chemical transport model of the lower atmosphere including non-methane volatile organic compound (NMVOC) chemistry. Above the boundary layer HCHO mixing ratios decreased with increasing altitude to a minimum level of 250 pptv at about 7 km. At higher altitudes (above 7 km) HCHO levels showed a strong dependency on the airmass origin. In airmasses from the North Atlantic/North American area HCHO levels were of the order of 300 pptv, a factor of 6 higher than values predicted by the model. Even higher HCHO levels, increasing to values of the order of 600 pptv at 11 km altitude, were observed in easterlies transporting air affected by the Indian monsoon outflow towards the Mediterranean basin. Only a small part (~30 pptv) of the large discrepancy between the model results and the measurements of HCHO in the free troposphere could be explained by a strong underestimation of the upper tropospheric acetone concentration by up to a factor of ten by the 3D-model. Therefore, the measurement-model difference in the upper troposphere remains unresolved, while the observed dependency of HCHO on airmass origin might indicate that unknown, relatively long-lived NMVOCs - or their reaction intermediates - associated with biomass burning are at least partially responsible for the observed discrepancies.

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