Aerosol chemical composition measured during the FAIRARI campaign, Po Valley, Italy, February⁠ – ⁠April 2022

Fredrik Mattsson, Almuth Neuberger, Liine Heikkinen, Paul Zieger, Claudia Mohr

This dataset provides the bulk aerosol chemical composition measured with a Soot-Particle Aerosol Mass Spectrometer (SP-AMS) from 8 February to 4 April 2022 at San Pietro Capofiume, northern Italy, during the Fog and Aerosol InteRAction Research Italy (FAIRARI) campaign 2021/2022.

Chemical species include the organics, nitrate, sulfate, ammonium, chloride and black carbon. The instrument was placed in the mobile aerosol-cloud laboratory (or SU-container), and sampled behind a 3-way switch connected to two inlets. The ambient aerosol was measured behind a whole-air inlet and the fog residuals were measured behind a ground-based counterflow virtual impactor (GCVI) inlet.

The chemical composition of aerosol particles is an important characteristic, influencing their optical properties and hygroscopicity, which in turn affect the climate. The aerosol optical properties determine their scattering or absorbing of solar radiation, while their hygroscopicity determines how likely they are to interact with clouds and fog.

AtmosphereAerosolsAerosol chemical compositionSP-AMSPo ValleyItalyFAIRARI

Name

Version

Citation

References

Mattsson F, and Neuberger A, and Heikkinen L, and Gramlich Y, and Paglione M, and Rinaldi M, and Decesari S, and Zieger P, and Riipinen I, and Mohr C (2025) Enrichment of organic nitrogen in fog residuals observed in the Italian Po Valley. Atmospheric Chemistry and Physics. https://doi.org/10.5194/acp-25-7973-2025

Neuberger A, Decesari S, Aktypis A, Andersen H, Baumgardner D, Bianchi F, Busetto M, Cai J, Cermak J, Dipu S, Ekman A, Fuzzi S, Gramlich Y, Haslett SL, Heikkinen L, Joutsensaari J, Kaltsonoudis C, Kangasluoma J, Krejci R, Lupi A, Marinoni A, Matrali A, Mattsson F, Mohr C, Nenes A, Paglione M, Pandis SN, Patel A, Riipinen I, Rinaldi M, Steimer SS, Stolzenburg D, Sulo J, Vasilakopoulou CN, Zieger P (2025) From molecules to droplets: The Fog and Aerosol InteRAction Research Italy (FAIRARI) 2021/22 campaign. Bulletin of the American Meteorological Society. https://doi.org/10.1175/bams-d-23-0166.1

Data description

Data provided was obtained using a soot-particle aerosol mass spectrometer (SP-AMS). The data is given at ambient pressure and temperature conditions.

The data has been cleaned from HEPA filter runs, calibrations, and measurement errors. All times in local time (CET) with format: yyyy-mm-dd HH:MM:SS.

All data are in μg/m³ and were measured using Laser OFF V-mode MS, except rBC which was measured in Laser ON V-mode MS.

The following corrections were done on all data:

1. Airbeam correction
2. Ionization efficiency and relative ionization efficiency based on calibrations using NH4NO3 (and Regal Black for rBC) during campaign
3. Composition dependent collection efficiency, time dependent.
4. Fragmentation table adaptation for air Fragmentation Patterns using HEPA filter periods in PIKA1.26.
5. Correction and validation using co-located HR-TOF-AMS (interstitial AMS), which in turn was validated against ion chromatography on PM1 filter samples).

Readme.txt contains the data description (same as below).

The following csv files are included, divided into five categories depending on what type of data they contain:

1-minute resolution timeseries of the PM1 bulk chemical composition, OA families, and elemental ratios

• FAIRARI_SP-AMS_HR_timeseries_ambient.csv includes ambient PM1 bulk chemical composition, OA families, and elemental ratios, collected behind the whole-air inlet.
• FAIRARI_SP-AMS_HR_timeseries_residuals.csv includes fog residual PM1 bulk chemical composition, OA families, and elemental ratios, collected behind the GCVI inlet.

These two csv files contain the following columns:

• datetime Date and time in local time (CET) with format YYYY-MM-DD hh:mm:ss
• HROrg High resolution mass concentration of organics (μg/m³)
• HRNO3 High resolution mass concentration of nitrates (μg/m³)
• HRSO4 High resolution mass concentration of sulfates (μg/m³)
• HRNH4 High resolution mass concentration of ammonium (μg/m³)
• HRChl High resolution mass concentration of chloride (μg/m³)
• HRBC High resolution mass concentration of black carbon (μg/m³)
• familyCH High resolution mass concentration CH-ions (μg/m³)
• familyCHO1 High resolution mass concentration of CHO_1-ions (μg/m³)
• familyCHOgt1 High resolution mass concentration of CHOgt1-ions(μg/m³)
• familyCHN High resolution mass concentration of CHN-ions (μg/m³)
• familyCHO1N High resolution mass concentration of CHO1N-ions (μg/m³)
• Ratio_O_C_IA Elemental ratio of oxygen:carbon in the organics
• Ratio_N_C_IA Elemental ratio of nitrogen:carbon in the organics

5-minute resolution timeseries of CHN1 and CHN2 mass concentrations.

Averaging was done with time_end as new time.

• FAIRARI_SP-AMS_HR_timeseries_CHN1_CHN2.csv includes CHN1 and CHN2 mass concentration (in μg/m³) measured in ambient and fog residuals.

This csv file contains the following columns:

• datetime Date and time in local time (CET) with format YYYY-MM-DD hh:mm:ss
• familyCHN1_ambient High resolution mass concentration of CHN1-ions (μg/m³) in non-fog ambient aerosol
• familyCHN1_fog_resid High resolution mass concentration of CHN1-ions (μg/m³) in fog residuals
• familyCHN2_ambient High resolution mass concentration of CHN2-ions (μg/m³) in non-fog ambient aerosol
• familyCHN2_fog_resid High resolution mass concentration of CHN2-ions (μg/m³) in fog residuals

Average high resolution (HR) mass spectra for the organic nitrogen (ON) ions

• FAIRARI_SP-AMS_ON_mass_spectra_ambient.csv includes average ambient ON mass spectra as percentage of total OA signal collected behind the whole-air inlet.
• FAIRARI_SP-AMS_ON_mass_spectra_fog_residuals.csv includes average fog residual ON mass spectra as percentage of total OA signal collected behind the GCVI inlet.
• FAIRARI_SP-AMS_ON_mass_spectra_fog_water.csv includes average fog water ON mass spectra as percentage of total OA signal from the fog water samples.
• FAIRARI_SP-AMS_ON_mass_spectra_interstitial.csv includes average interstitial ON mass spectra as percentage of total OA signal collected behind the PM2.5 inlet.

These 4 csv files contain the following columns:

• amu_mz_HR Mass to charge (m/z) ratio
• familyCHN1 Fraction of CHN1-ions signal over total organic signal
• familyCHN2 Fraction of CHN2-ions signal over total organic signal
• familyCHO1N Fraction of CHO1N-ions signal over total organic signal

Chemically resolved aerosol mass size distribution data over time

• FAIRARI_SP-AMS_mass_size_dist_timeseries_NH4_ambient.csv includes the ambient NH4 mass size distribution collected behind the whole-air inlet.
• FAIRARI_SP-AMS_mass_size_dist_timeseries_NH4_fog_resid.csv includes the fog residual NH4 mass size distribution collected behind the GCVI inlet.
• FAIRARI_SP-AMS_mass_size_dist_timeseries_NO3_ambient.csv includes the ambient NO3 mass size distribution collected behind the whole-air inlet.
• FAIRARI_SP-AMS_mass_size_dist_timeseries_NO3_fog_resid.csv includes the fog residual NO3 mass size distribution collected behind the GCVI inlet.
• FAIRARI_SP-AMS_mass_size_dist_timeseries_OA_ambient.csv includes the ambient OA mass size distribution collected behind the whole-air inlet.
• FAIRARI_SP-AMS_mass_size_dist_timeseries_OA_fog_resid.csv includes the fog residual OA mass size distribution collected behind the GCVI inlet.
• FAIRARI_SP-AMS_mass_size_dist_timeseries_rBC_ambient.csv includes the ambient rBC mass size distribution collected behind the whole-air inlet.
• FAIRARI_SP-AMS_mass_size_dist_timeseries_rBC_fog_resid.csv includes the fog residual rBC mass size distribution collected behind the GCVI inlet.
• FAIRARI_SP-AMS_mass_size_dist_timeseries_SO4_ambient.csv includes the ambient SO4 mass size distribution collected behind the whole-air inlet.
• FAIRARI_SP-AMS_mass_size_dist_timeseries_SO4_fog_resid.csv includes the fog residual SO4 mass size distribution collected behind the GCVI inlet.

These 10 csv files contain the following columns:

• datetime Date and time in local time (CET) with format YYYY-MM-DD hh:mm:ss
• column 2 - 51 DM/dlog10dva (μg/m³), where each column corresponds to the rows 1 - 50 of FAIRARI_SP-AMS_mass_size_diameter.csv

Particle diameter (nm)

• FAIRARI_SP-AMS_mass_size_diameter.csv includes one column of 50 rows which corresponds to the particle diameter of column 2-51 of FAIRARI_SP-AMS_mass_size_dist_timeseries_...csv

This csv file contains the following column:

• diameter_Dva_nm Aerodynamic vacuum particle diameter (D_va) in nanometers (nm)

Comments

Further details on the instrument, field campaign and data processing can be found in Mattsson et al. (2025) and Neuberger et al. (2025).

Project

European Union’s Horizon 2020 research and innovation programme (project FORCeS under grant agreement No 821205); European Research Council (Consolidator grant INTEGRATE No 865799); Knut and Alice Wallenberg Foundation (grant numbers 2021.0169 and 2021.0298).

Publisher

Bolin Centre Database

License

Open Data Commons Attribution License (ODC-By) v1.0

First name

Fredrik

Last name or organisation

Mattsson

Email address

paul.zieger@aces.su.se

Address

Department of Environmental Science; Stockholm University

Postal code

SE-106 91

City

Stockholm

Country

Sweden

GCMD science keyword

Earth science > Atmosphere > Aerosols

GCMD location

Continent > Europe > Southern Europe > Italy

Dataset language

English

Begin date

2022-02-08

End date

2022-04-04

DOI

Time