Interstitial aerosol chemical composition measured by HR-TOF-AMS during the FAIRARI campaign, Po Valley, Italy, Feb.–⁠May 2022

Matteo Rinaldi, Marco Paglione, Stefano Decesari

This dataset provides the bulk aerosol chemical composition measured with a High-Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-TOF-AMS) from 17 February to 11 May 2022 at San Pietro Capofiume, northern Italy, during the Fog and Aerosol InteRAction Research Italy (FAIRARI) campaign 2021/2022.

The HR-ToF-AMS provides measurements of the non-refractory sulfate, nitrate, ammonium, chloride, and organic mass of the submicron particles (NR-PM1).

The chemical composition of aerosols is a key factor linking air pollution to both human health and climate. It controls aerosol toxicity and health impacts, as well as optical properties and hygroscopicity, which determine their direct radiative effects and their indirect effects on climate through cloud and fog formation and modification.

AtmosphereAerosolsAtmosphereAerosolsAerosol chemical compositionHR-TOF-AMSPo Valley, ItalyFAIRARI

Name

Version

Citation

References

Mattsson F, Neuberger A, Heikkinen L, Gramlich Y, Paglione M, Rinaldi M, Decesari S, Zieger P, Riipinen I, Mohr C (2025) Enrichment of organic nitrogen in fog residuals observed in the Italian Po Valley. Atmospheric Chemistry and Physics 25:7973–7989. 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 106:E23–E50. https://doi.org/10.1175/bams-d-23-0166.1

Data description

The data are provided in one comma-separated values (csv) file with the following variables:

• datetime_LT 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)
• fog_label: reporting a flag to indicate the occurrence of fog events (fog) and the periods considered pre-fog (pre) and post-fog (post)

The file includes the 5-minute resolution timeseries of the bulk chemical composition of ambient NR-PM1 collected behind the PM2.5-air inlet (therefore, during fog events, representing the chemical composition of interstitial, meaning “non-activated”, particles).

Data obtained using a high-resolution time-of-flight mass spectrometer (HR-TOF-AMS, Aerodyne inc). The data is given at ambient pressure and temperature conditions.

Comments

Sampling

The instrument was placed in the CNR-container and sampled behind a PM2.5 inlet. Therefore, during fog events, this AMS sampled only the interstitial (non-activated) particles, while fog droplets (activated particles) could not reach the sampling line because of the smaller cutoff of the sampling head (Neuberger et al., 2025).

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

Data treatment and corrections

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 V-mode MS.

The following corrections were done on all data:

1. Airbeam correction
2. Ionization efficiency and relative ionization efficiency based on periodic calibrations using NH4NO3 during the 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 SMPS and OPC and comparison against ion chromatography on PM1 filter samples.

Associated datasets

The current dataset is part of a collection of datasets from The fog and aerosol interaction research Italy (FAIRARI) campaign, November 2021 to May 2022.

Project

European Union’s Horizon 2020 research and innovation programme (Project FORCeS under Grant Agreement 821205)

Publisher

Bolin Centre Database

License

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

First name

Marco

Last name or organisation

Paglione

Email address

marco.paglione@cnr.it

Address

Institute of Atmospheric Sciences and Climate (ISAC); National Research Council of Italy (CNR)

Postal code

IT-40129

City

Bologna

Province or state

Bologna (BO)

Country

Italy

GCMD science keyword

Earth science

GCMD location

Continent > Europe > Southern Europe > Italy

Begin date

2022-02-17

End date

2022-05-11

DOI

Time